The Ore Minerals Under the Microscope, Volume 3: An Optical Guide (Atlases in Geoscience)

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ATLASES IN GEOSCIENCE, 3

The Ore Minerals Under the Microscope An Optical Guide

This page intentionally left blank

ATLASES IN GEOSCIENCE, 3

The Ore Minerals Under the Microscope An Optical Guide

Edited by Bernhard Pracejus

Amsterdam – Boston – Heidelberg – London – New York – Oxford – Paris San Diego – San Francisco – Singapore – Sydney – Tokyo

Elsevier Radarweg 29, PO Box 211, 1000 AE Amsterdam, The Netherlands Linacre House, Jordan Hill, Oxford OX2 8DP, UK

First edition 2008 Copyright © 2008 Elsevier B.V. All rights reserved No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, mechanical, photocopying, recording or otherwise without the prior written permission of the publisher Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone (+44) (0) 1865 843830; fax (+44) (0) 1865 853333; email: [email protected]. Alternatively you can submit your request online by visiting the Elsevier web site at http://elsevier.com/locate/ permissions, and selecting Obtaining permission to use Elsevier material Notice No responsibility is assumed by the publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein. Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made

British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress ISBN: 978-0-444-52863-6 ISSN: 1574-1966

For information on all Elsevier publications visit our website at www.elsevierdirect.com

Printed and bound in Hungary 08 09 10 11 12 13

10 9 8 7 6 5 4 3 2 1

Table of Contents Page XV XVI XVII

Acknowledgements & Sample Sources Instrument Settings Preface

1 3

Mineral Descriptions Explanations & Abbreviations Mineral

Strunz-Group

Page

I - Elements I/A - Metallic and Intermetallic Compounds, Carbides, Nitrides, Phosphides and Silicides Copper I/A.01-10 4 Silver I/A.01-20 6 Gold I/A.01-40 8 Auricupride I/A.01-50 10 Amalgam I/A.02-30 12 Aluminium I/A.03-05 14 Cadmium I/A.04-40 16 Lead I/A.05-20 18 Iron I/A.07-10 20 Kamacite I/A.07-20 22 Taenite I/A.08-20 24 Awaruite I/A.08-40 26 Cohenite I/A.09-50 28 Carlsbergite 30 I/A.10-20 Sinoite I/A.10-50 32 Schreibersite I/A.11-20 34 Gupeiite I/A.12-30 36 Xifengite I/A.12-40 38 Fersilicite I/A.12-50 40 Hexaferrum I/A.13-15 42 Osmium I/A.13-20 44 Ruthenium I/A.13-30 46 Rutheniridosmine I/A.13-40 48 Iridium I/A.14-30 50 Platinum I/A.14-70 52 Hongshiite I/A.14-90 54 Isoferroplatinum I/A.15-10 56 I/A.15-30 58 Tulameenite I/A.16-20 60 Atokite Niggliite I/A.16-40 62 Stannopalladinite I/A.16-50 64 Palarstanide I/A.16-60 66 Plumbopalladinite I/A.16-70 68 Paolovite I/A.17-10 70 Cabriite I/A.17-20 72 Taimyrite I/A.17-30 74 I/B - Semimetals and Nonmetals Arsenic Antimony Bismuth Arsenolamprite

I/B.01-10 I/B.01-30 I/B.01-40 I/B.01-50 V

76 78 80 82

Mineral

Strunz-Group

Graphite Sulfur Selenium Tellurium

I/B.02-10 I/B.03-10 I/B.03-30 I/B.03-40

II - Sulfides and Sulphosalts II/A - Alloys and Alloy-like Compounds, with Copper, Silver, Gold and Nickel Algodonite II/A.01-10 Domeykite II/A.01-20 Dyscrasite II/A.02-20 Maucherite II/A.04-30 Arsenopalladinite II/A.05-40 Isomertieite II/A.05-50 Stibiopalladinite II/A.05-80 Palladodymite II/A.05-102 Rhodarsenide II/A.05-105 Telargpalite II/A.07-10 Oulankaite II/A.07-35 Temagamite II/A.07-50 II/B - Sulfides with Metal : Sulfur, Selenium and Tellurium > 1:1 Chalcocite II/B.01-10 Djurleite II/B.01-20 Digenite II/B.01-30 Anilite II/B.01-50 Betekhtinite II/B.02-10 Bornite II/B.02-30 Berzelianite II/B.03-10 Crookesite II/B.03-30 Umangite II/B.03-50 Weissite II/B.04-10 Rickardite II/B.04-20 Argentite II/B.05-02 II/B.05-10 Acanthite Naumannite II/B.05-30 Hessite II/B.05-40 Jalpaite II/B.06-10 Stromeyerite II/B.06-30 Eucairite II/B.06-40 Fischesserite II/B.07-50 Petzite II/B.07-60 Argyrodite II/B.08-10 Canfieldite II/B.08-20 Shandite II/B.12-20 Parkerite II/B.12-30 Heazlewoodite II/B.12-40 Oregonite II/B.12-50 Hauchecornite II/B.15-20 Pentlandite II/B.16-10 Miassite II/B.16-80 Mackinawite II/B.17-10 Godlevskite II/B.17-20

VI

Page 84 86 88 90

92 94 96 98 100 102 104 106 108 110 112 114

116 118 120 122 124 126 128 130 132 134 136 138 140 142 144 146 148 150 152 154 156 158 160 162 164 166 168 170 172 174 176

Mineral

Strunz-Group

II/C - Sulfides with Metal : Sulfur, Selenium and Tellurium = 1:1 Sphalerite II/C.01-10 Metacinnabar II/C.01-30 Stilleite II/C.01-40 Tiemannite II/C.01-50 Coloradoite II/C.01-60 Lautite II/C.02-10 Chalcopyrite II/C.03-10 Eskebornite II/C.03-20 Lenaite II/C.03-25 Gallite II/C.03-30 Roquesite II/C.03-40 Isocubanite II/C.04-50 Orickite II/C.04-60 Luzonite II/C.06-10 Famatinite II/C.06-20 Permingeatite II/C.06-30 Briartite II/C.06-40 Stannite II/C.06-60 Kesterite II/C.06-80 Sakuraiite II/C.06-130 Stannoidite II/C.07-10 Mawsonite II/C.08-20 Renierite II/C.10-10 Germanite II/C.10-20 Colusite II/C.10-40 Sulvanite II/C.10-60 Tennantite II/C.11-10 Tetrahedrite II/C.11-40 Schwazite II/C.11-40 Freibergite II/C.11-50 Goldfieldite II/C.11-60 Wurtzite II/C.13-10 Greenockite II/C.13-30 Enargite II/C.14-10 II/C.14-20 Cubanite II/C.14-30 Sternbergite II/C.14-40 Argentopyrite Niningerite II/C.15-10 Oldhamite II/C.15-20 Alabandite II/C.15-30 Galena II/C.15-40 Clausthalite II/C.15-50 Altaite II/C.15-60 Miargyrite II/C.16-10 Aramayoite II/C.16-20 Matildite II/C.16-30 Herzenbergite II/C.17-10 Stistaite II/C.17-20 Teallite II/C.17-40 Franckeite II/C.17-70 Cylindrite II/C.17-80 Cinnabar II/C.18-10 II/C.19-10 Troilite VII 7

Page 178 180 182 184 186 188 190 192 194 196 198 200 202 204 206 208 210 212 214 216 218 220 222 224 226 228 230 232 234 236 238 240 242 244 246 248 250 252 254 256 258 260 262 264 266 268 270 272 274 276 278 280 282

Mineral

Strunz-Group

Page

II/C.19-20 II/C.19-50 II/C.20-20 II/C.20-30 II/C.20-40 II/C.20-100 II/C.20-110 II/C.20-130 II/C.21-30 II/C.22-10 II/C.22-20 II/C.22-30 II/C.23-20 II/C.23-40 II/C.23-50 II/C.24-10 II/C.25-20 II/C.25-30

284 286 288 290 292 294 296 298 300 302 304 306 308 310 312 314 316 318

Pyrrhotite Smythite Nickeline Breithauptite Freboldite Polarite Sobolevskite Cherepanovite Millerite Covellite Klockmannite Idaite Valleriite Tochilinite Vyalsovite Vulcanite Braggite Cooperite

II/D - Sulfides with Metal : Sulfur, Selenium and Tellurium < 1:1, Tellurides with Copper, Silver and Gold Linnaeite II/D.01-20 320 Polydymite II/D.01-30 322 Carrollite II/D.01-40 324 Violarite II/D.01-70 326 Siegenite II/D.01-80 328 Indite II/D.01-90 330 Daubreelite II/D.01-100 332 Bornhardtite II/D.01-120 334 Tyrrellite II/D.01-140 336 Cuprorhodsite II/D.02-20 338 Cuproiridsite II/D.02-30 340 Malanite II/D.02-40 342 Kashinite II/D.06-10 344 Bowieite II/D.06-20 346 Edgarite II/D.07-20 348 Stibnite II/D.08-20 350 Bismuthinite II/D.08-40 352 Guanajuatite II/D.08-50 354 Ottemannite II/D.08-60 356 Tellurantimony II/D.09-10 358 Tellurobismuthite II/D.09-20 360 Paraguanajuatite II/D.09-30 362 Tetradymite II/D.09-60 364 Joséite II/D.11-30 366 Pilsenite II/D.11-40 368 II/D.15-10 370 Montbrayite Nagyagite II/D.15-20 372 Sylvanite II/D.16-20 374 Krennerite II/D.16-30 376 Calaverite II/D.16-40 378 Villamaninite II/D.17-20 380 Pyrite II/D.17-30 382 Cattierite II/D.17-40 384 VIII

Mineral Vaesite Hauerite Penroseit Laurite Erlichmanite Sperrylite Aurostibite Geversite Insizwaite Padmaite Cobaltite Gersdorffite Ullmannite Hollingworthite Irarsite Marcasite Ferroselite Hastite Frohbergite Mattagamite Froodite Arsenopyrite Glaucodot Gudmundite Löllingite Safflorite Rammelsbergite Pararammelsbergite Molybdenite Jordisite Tungstenite Berndtite Melonite Moncheite Skutterudite Nickel-skutterudite

Strunz-Group

Page

II/D.17-50 II/D.17-60 II/D.17-90 II/D.17-100 II/D.17-110 II/D.17-120 II/D.17-130 II/D.17-140 II/D.17-150 II/D.17-175 II/D.18-10 II/D.18-20 II/D.18-40 II/D.18-50 II/D.18-60 II/D.20-10 II/D.20-20 II/D.20-30 II/D.20-50 II/D.20-60 II/D.21-10 II/D.22-10 II/D.22-20 II/D.22-30 II/D.23-10 II/D.23-20 II/D.23-30 II/D.24-20 II/D.25-10 II/D.25-20 II/D.25-40 II/D.28-10 II/D.28-30 II/D.28-50 II/D.29-10 II/D.29-20

386 388 390 392 394 396 398 400 402 404 406 408 410 412 414 416 418 420 422 424 426 428 430 432 434 436 438 440 442 444 446 448 450 452 454 456

II/E - Sulfosalts (S : As,Sb,Bi = x), Sulfosalts with Predominant Iron and Copper x = 2.0 Berthierite II/E.01-10 458 Wittichenite II/E.03-20 460 Chalcostibite II/E.04-10 462 Emplectite II/E.04-20 464 Polybasite II/E.05-50 466 Stephanite II/E.06-10 468 Proustite II/E.07-10 470 Pyrargyrite II/E.07-20 472 Xanthoconite II/E.07-30 474 Samsonite II/E.07-50 476 II/E.13-45 478 Hutchinsonite II/E.13-50 480 Lorandite II/E.15-10 482 Jordanite II/E.15-20 484 Geocronite II/E.15-30 486 Gratonite II/E.15-40 488 Meneghinite IX

Mineral Seligmannite Bournonite Freieslebenite Diaphorite Owyheeite Dufrenoysite Falkmanite Boulangerite Semseyite Heteromorphite Plagionite Jamesonite Ramdohrite Andorite Baumhauerite Rathite Sartorite Zinckenite Aikinite Emilite Lindströmite Krupkaite Paarite Lillianite Kobellite Cosalite Weibullite Cannizzarite Felbertalite Galenobismuthite

Strunz-Group

Page

II/E.16-10 II/E.16-20 II/E.17-20 II/E.17-30 II/E.17-50 II/E.18-10 II/E.19-10 II/E.19-30 II/E.21-20 II/E.21-30 II/E.21-40 II/E.22-10 II/E.23-30 II/E.23-40 II/E.24-10 II/E.25-20 II/E.25-30 II/E.26-10 II/E.30-10 II/E.30-25 II/E.30-40 II/E.30-50 II/E.30-54 II/E.31-20 II/E.33-20 II/E.34-10 II/E.34-30 II/E.34-60 II/E.34-85 II/E.34-110

490 492 494 496 498 500 502 504 506 508 510 512 514 516 518 520 522 524 526 528 530 532 534 536 538 540 542 544 546 548

II/F - Sulfides with Nonmetallic Properties, Arsenic-Sulfides Patronite II/F.01-10 Realgar II/F.02-30 Orpiment II/F.02-70 Djerfisherite II/F.06-10 Rasvumite II/F.07-10 Bartonite II/F.07-20 Schöllhornite II/F.08-20 Cronusite II/F.08-30 Erdite II/F.09-10 Kermesite II/F.11-10

550 552 554 556 558 560 562 564 566 568

II/X-Unclassified Strunz Sulfides and sulphosalts II/X.00-00 Bravoite

570

III - Halogenides III/A - Simple Halogenides, without Water Metal : Halogen = 1 : 1 Chlorargyrite III/A.02-50 Iodargyrite III/A.03-10 Calomel III/A.05-10 Fluorite III/A.08-10

X

572 574 576 578

Mineral

Strunz-Group

Page

III/D-Oxi-halogenides with Mg-Mn-Cu-Zn-Sn Atacamite III/D.01-30

580

IV - Oxides IV/A - Oxides with Metal : Oxygen = 1:1 and 2:1 (M2O, MO) Cuprite IV/A.02-10 Zincite IV/A.03-20 Wüstite IV/A.04-20 Manganosite IV/A.04-40 Tenorite IV/A.05-10 Paramelaconite IV/A.05-20 Delafossite IV/A.05-30 IV/A.05-50 Crednerite IV/A.06-20 Litharge IV/A.06-30 Massicot

582 584 586 588 590 592 594 596 598 600

IV/B - Oxides with Metal : Oxygen = 3:4 (Spinel type M3O4 and related), Aluminat-Spinels Hercynite IV/B.01-20 602 Galaxite IV/B.01-30 604 Gahnite IV/B.01-40 606 Magnetite IV/B.02-20 608 Jacobsite IV/B.02-30 610 Franklinite IV/B.02-60 612 Chromite IV/B.03-20 614 Ulvite IV/B.04-40 616 Hausmannite IV/B.05-10 618 Hetaerolite IV/B.05-40 620 IV/B.05-50 Hydrohetaerolite 622 IV/B.05-60 624 Marokite IV/B.06-50 626 Minium IV/C - Oxides with Metal : Oxygen = 2:3 (M2O3 and related compounds) Valentinite IV/C.01-20 Bismite IV/C.02-30 Bixbyite IV/C.03-10 Corundum IV/C.04-10 Hematite IV/C.04-20 Eskolaite IV/C.04-30 Karelianite IV/C.04-40 Geikielite IV/C.05-10 Ilmenite IV/C.05-20 Pyrophanite IV/C.05-30 Maghemite IV/C.06-10 Högbomite IV/C.07-10 Magnetoplumbite IV/C.08-40 Plumboferrite IV/C.08-50 Loveringite IV/C.09-30 Davidite-(Ce, La, Y) IV/C.09-70 Perovskite IV/C.10-20 Macedonite IV/C.10-80 Stibiconite IV/C.11-50 Bindheimite IV/C.11-70 Pyrochlore IV/C.17-10 Armalcolite IV/C.24-10 XI

628 630 632 634 636 638 640 642 644 646 648 650 652 654 656 658 660 662 664 666 668 670

Mineral

Strunz-Group

Page

IV/C.24-20

672

Pseudobrookite

IV/D - Oxides with Metal : Oxygen = 1:2 (MO2 and related compounds) Quartz IV/D.01-10 Silica, amorphous IV/D.01-80 Rutile IV/D.02-10 Pyrolusite IV/D.02-20 Polianite IV/D.02-20 Cassiterite IV/D.02-40 Plattnerite IV/D.02-60 Ilmenorutile IV/D.03-10 Tapiolite IV/D.04-00 Cryptomelane IV/D.08-20 Hollandite IV/D.08-60 IV/D.08-70 Coronadite IV/D.09-10 Todorokite IV/D.09-20 Woodruffite IV/D.09-30 Romanéchite IV/D.10-10 Ramsdellite Nsutite IV/D.10-20 Anatase IV/D.14-10 Wolframite IV/D.16-00 Hübnerite IV/D.16-10 Ferberite IV/D.16-20 Ferrocolumbite IV/D.18-30 Ferrotantalite IV/D.18-50 Brannerite IV/D.22-20 Foordite IV/D.29-10 Thoreaulite IV/D.29-20 Baddeleyite IV/D.31-10 IV/D.31-60 Uraninite IV/D.31-60 Thucholite

674 676 678 680 682 684 686 688 690 692 694 696 698 700 702 704 706 708 710 712 714 716 718 720 722 724 726 728 730

IV/E - Oxides with Metal : Oxygen < 1:2 (M2O5, MO3) Molybdite IV/E.03-10

732

IV/F - Hydroxides and Oxidic Hydrates, Water-bearing Oxides with Layered Structure Pyrochroite IV/F.03-30 734 Goethite IV/F.06-30 736 Lepidocrocite IV/F.06-40 738 Manganite IV/F.06-70 740 Groutite IV/F.06-80 742 Feitknechtite IV/F.06-90 744 Lithiophorite IV/F.07-10 746 Heterogenite IV/F.07-30/40 748 Guyanaite IV/F.07-60 750 IV/F.11-20 752 Chalcophanite IV/F.11-30 754 Birnessite IV/F.14-10 756 Quenselite IV/F.15-10 758 Söhngeite IV/F.15-20 760 Dzhalindite IV/G - Vanadiumoxides (with V4+/5+), Group-vanadates Melanovanadite IV/G.10-10 XII

762

Mineral

Strunz-Group

IV/K - Sulfides, Selenides, Tellurides with [XO3]2- groups and Related Structures Chalcomenite IV/K.06-10 V - Nitrates, Carbonates and Borates V/B - Waterfree Carbonates [CO3]2- without unfamiliar anions Calcite V/B.02-20 Siderite V/B.02-40 Rhodochrosite V/B.02-50 V/B.04-40 Cerussite

Page 764

766 768 770 772

V/C - Waterfree Carbonates with Unfamiliar Anions V/C.01-10 Azurite V/C.01-20 Malachite V/C.06-30 Defernite

774 776 778

V/G - “Insel” Borates, [BO3]3- “inseln” Jimboite Hulsite Ludwigite Vonsenite Gaudefroyite

780 782 784 786 788

V/G.01-20 V/G.03-40 V/G.04-10 V/G.04-20 V/G.04-100

VI - Sulfates, Chromates, Molybdates and Tungstates VI/A - Waterfree Sulfates [SO4]2- without Unfamiliar Anions. Cations of Medium Size VI/A.08-50 790 Anhydrite VI/A.09-20 792 Barite VI/A.09-50 794 Anglesite VI/B - Waterfree Sulfates [SO4]2- with Unfamiliar Anions. Cations of Medium Size Jarosite VI/B.11-60

796

VI/C - Water-bearing Sulfates without Unfamiliar Anions. Cations of Medium Size VI/C.22-20 798 Gypsum VI/F - Chromates [CrO4]2Crocoite Vauquelinite

VI/F.01-30 VI/F.02-10

800 802

VI/G - Molybdates [MoO4]2- and Wolframates [WO4]2Scheelite VI/G.01-20 Wulfenite VI/G.01-30

804 806

VII - Phosphates, Arsenates and Vanadates VII/A - Waterfree Phosphates [PO4]3- without Unfamiliar Anions, Cations of Small Size: Li, Be, Al Monazite VII/A.15-20 808 VII/B - Waterfree Phosphates with Unfamiliar Anions F, Cl, O, OH, Cations of Very Small Size: Li, Be Libethenite VII/B.06-10 810 Duftite VII/B.26-80 812 Descloizite VII/B.27-20 814 Pyromorphite VII/B.39-150 816 XIII

Mineral Mimetite Vanadinite Sahlinite

Strunz-Group

Page

VII/B.39-160 VII/B.39-170 VII/B.40-30

818 820 822

VII/C - Water-bearing Phosphates without Unfamiliar Anions. Cations of Medium and Small Size: Be and Mn, Fe, Cu, Zn, Mg Erythrine VII/C.13-70 824 Annabergite VII/C.13-80 826 VIII - Silicates VIII/A - Nesosilicates, with [SiO4]4- groups, Cations of Tetrahedric Orientation [4] Willemite VIII/A.01-20 Olivine VIII/A.04-00 VIII/A.08-20 Almandine VIII/A.08-160 Henritermierite VIII/A.09-40 Coffinite

828 830 832 834 836

VIII/B - Nesosubsilicates, with Anions Unfamiliar to Tetraheders, Cations of Octahedral and Tetrahedral Orientation [4/6] VIII/B.02-70 838 Topaz VIII/B.09-03 840 Braunite Neltnerite VIII/B.09-07 842 Titanite VIII/B.12-10 844 VIII/C - Sorosilicates, with [Si2O7]6-, without Anions Unfamiliar to Tetraheders Ilvaite VIII/C.10-20 Kentrolite VIII/C.20-20

846 848

VIII/E - Cyklosilicates, Triplet Rings [Si3O9]6Chrysocolla VIII/E.21-20

850

VIII/F - Inosilicates (Chain and Band) Double Chains [Si2O6]4Hedenbergite VIII/F.01-60 Riebeckite VIII/F.08-50 Bustamite VIII/F.18-40 Rhodonite VIII/F.27-10

852 854 856 858

VIII/H - Phyllosilicates (Layered), Tetragonal or Pseudotetragonal Layered Structures [Si4O10]4- and others Muscovite VIII/H.10-70 860 VIII/H.11-00 Biotite 862 Chamosite VIII/H.23-30 864

Page 867 870 871

Bibliography / Print Media Bibliography / Electronic Media Mineral Index

XIV

Acknowledgements & Sample Sources This book would not have been written were it not for the everlasting patience of my dear wife Ramona, who tolerated my long-lasting mental absence when working behind the microscope or the connected computer and for tirelessly assisting me with data compilation. Our son André also took part in the data gathering, for which I am quite thankful. Many polished sections had not been looked after for decades and D. Lange (FU Berlin) provided much needed help in upgrading severely oxidised samples. Since it is very difficult to gather the vast amount of different ore minerals included in this atlas, I am very much indepted to a number of colleagues, who provided many uncommon samples. In particular, the use of Ramdohr’s famous research collection, now held at the Mineralogy Department of Heidelberg University, as well as the samples from the BGR and the private collection of T. Witzke proved to be valuable sources for many specimens. All published photo contributions are thankfully referenced below and cited in the text with the respective abbreviation in square brackets (e.g., [d]). Abbreviation* Name [a - c] Author’s research and Freie Universität Berlin teaching collections

[d]

[e]

[f]

[g]

[h] [i]

[j]

[k] [l] [m] [n] [o] *(as

Affiliation/Address Luzerner Str. 10-12, D-12205 Berlin, Germany – Freie Universität Berlin, FB Geowissenschaften, Institut für Geologische Wissenschaften, FR Geochemie, Hydrogeologie, Mineralogie, Malteserstr. 74-100, D-12249 Berlin, Germany Bundesanstalt für Geowissenschaften und Dr. Frank Melcher & Rohstoffe (BGR), Stilleweg 2, D-30655 HanDr. Thomas Oberthür nover, Germany Dr. Thomas Kenkmann Museum für Naturkunde der Humboldt-Universität zu Berlin, Invalidenstr. 43, D-10115 Berlin, Germany Prof. Dr. Robert Marschik & Ludwig-Maximilians Universität, Department für Geo- und Umweltwissenschaften, RessourDr. Ana Rieger cengeologie, Luisenstr. 37, D-80333 München, Germany Dr. Thomas Seifert TU Bergakademie Freiberg, Institute of Mineralogy, Department of Economic Geology, Brennhausgasse 14, D-09596 Freiberg, Germany Dr. Thomas Witzke Urho-Kekkonen-Str. 9, D-18147 Rostock, Germany Dipl.-Geol. David van Acken Freie Universität Berlin, FB Geowissenschaften, Institut für Geologische Wissenschaften, FR Geochemie, Hydrogeologie, Mineralogie, Malteserstr. 74-100, D-12249 Berlin, Germany Prof. Dr. Rainer Altherr & Mineralogisches Institut, Universität Heidelberg, Im Neuenheimer Feld 236, D-69120 HeiDr. rer. nat. Michael Hanel delberg, Germany Dr. rer. nat. Erio Rahders Laubsängerweg 45, D-12351 Berlin, Germany Prof. Dr. Supriya Roy Department of Geological Sciences, Jadavpur University, Calcutta - 700 032, India Dr. rer. nat. Hans-Peter Witzlebenstr. 19, D-14057 Berlin, Germany Röper Prof. Dr.-Ing. Peter Halbach Sodenstr. 19, D-12309 Berlin, Germany Dr. Michael Quednau Eichenstraße 15, 61476 Kronberg, Germany

cited in the mineral description text) XV

Instrument Settings Model Lamp Position Filter Aperture Objectives

Microscope Zeiss Axioplan 8 none 2nd to last marking Air (no oil objectives)

Model Optical Zoom Objektive Picture Size/Quality* Rotation* Focusing Point* Makro* AF-assist Light* AF Operation* Zoom*

Camera Canon PowerShot A70 5.4 - 16.2mm Large/Super Fine - 2048x1536 ( 1 MB) 0 degree Automatic Selection Off Off AF Lock 1.3x to 3.2x (also further enhanced electronically)

Flash* Flash Quality* White Balance* Exposure Compensation* Flash Exposure Compensation* Metering Mode* ISO Speed* Photo Effect* Tv/Av Setting* Av* Tv* *(Software

Nicols // Off / Fluorescent 0 / Evaluative 50 Vivid Manual 8.0 1/250 to 1/2000

Settings for “Canon RemoteCapture”)

XVI

Nicols + Off / Fluorescent 0 / Evaluative 50 Vivid Manual 8.0 1/3 to 1/50

Preface Having been involved with ore microscopy for many years, I came to the conclusion that the magnificent work by Ramdohr (1969) on ore petrography needed to be supplemented by colour photos for as many different ore minerals as possible. It is simply impossible to deduce colour tints from black and white micrographs or descriptions alone (not to mention the many ill-tinted micrographs found on the internet). This task was quite daunting, because of the large number of minerals to be photographed. However, tools that were not accessible to Ramdohr, i.e., a desktop computer connected to a digital camera that was mounted on the microscope, eased the challenge considerably. This atlas does not attempt to be a handbook on how to examine ore minerals under the microscope (see following paragraph for some of the respective literature) or distinguish textures for obtaining genetic information, but rather it is meant as a search file for comparative use. Therefore, all text is limited to a minimum. This seems to be contradicted by the fact that the tables relating to an individual mineral are repeated for other members of the same group. Nevertheless, in order to show all relevant information close to the particular photo plate without the need to further search for comprehensive data tabulations, I adopted this approach. Ore minerals generally don’t occur just by themselves and, thus, a number of common gangue minerals are incorporated in this book, together with secondary alteration minerals. The latter present a further tool for the identification of entire mineral associations, because various elements exhibit very typical colours in their oxidised states. Examples are copper phases with green, blue, and sometimes red tinges or cobalt with pink shades, while iron shows pronounced tones of red, brown, and occasionally green. The term gangue minerals can also be fairly misleading for several reasons: a) it constitutes a more economic approach than a strict scientific meaning - a particular gangue mineral may be considered as waste in one deposit and as ore mineral in another (e.g., hedenbergite), b) its meaning shifts over time - sphalerite, for instance, was dumped by early miners, while it is being mined today. Strunz (2001) provides the mineralogical frame in which the minerals of this book are arranged and presented. This grouping of interrelated compounds also makes sense with respect to optical characteristics because of distinctive similarities within the respective groups. Such semblance also proves to be a valuable tool in the identification of unknown minerals. Other books on ore microscopy, which were used during the preparation phase for this atlas, are Baumann and Leeder (1991), Craig and Vaughan (1981), Gierth (1989), Mücke (1989), and Oelsner (1960), while Criddle and Stanley (1986) and Rösler (1991) were frequently consulted for optical and mineralogical information, respectively. Further helpful publications on mineralogy and geochemistry were by Harris and Burke (1970), Lawrence (1998), Makeyev et. al. (1999), Mücke et al. (1999), Naldrett (2005), Strunz et al. (1958). The literature pertaining to the investigated mineral deposits is tremendous and it would have been superfluous to list it comprehensively. However, the most important publications for this atlas are the following ones (excluding those already mentioned above): Barnes and Hay (1983), Blatter (1997), Boström et al. (1979), Cabri and Laflamme (1997), Cairncross (2004), Cook (1979), Dobrovolskaya (1999), Dunn (1995), Dyuzhikov et al. (1999), Excursion-Participants (2002), Favreau and Dietrich (2006), Flach (1984), Garuti et al. (1995), Graeme (1981), Graeme (1993), Graeser (1965), Grokhovskaya (1999), Hammer and Peterson (1968), Hernandez et al. (1999), Holtstam and Langhof (1999), Jahn (1991), Keller (1984), Lahl (2005), Leydet (2006), Lhoest (1995), Lombaard (1986), Martin et al. (1994), Nysten et al. (1999), Ondruš et al. (1997), Parafiniuk and Domanska (2002), Pauliš and Haake (1991), Pawlowski (1991), Ream (2004), Rieck (1993), Sejkora and Tvrdý (2002), Shiga (1987), Sokatsch and Weiss (2001), Stahle et al. (2002), Stekhin (1994), Strunz et al. (1958), Szentpéteri et al. (1999), Torgashin (1994), Torres-Ruiz et al. (1996), Walenta (1992), Watanabe (1959), Watanabe et al. (1960), Watkinson (1999), Weiß (1990), Whitehead (1919), Wilson (1950a, b), Wittern (2001). XVII

A fast internet access helped to obtain additional information, whenever necessary. An enormous wealth of data regarding mineral associations from world-wide locations was found at mindat.org an exquisite source of information, particularly in cases when rare samples were examined for which there was no proper mineral inventory. Further deposit descriptions originated from: binn.strahlen.org, franklin-sterlinghill.com, bergbauverein-ronneburg.de, ge-at.iastate.edu, geology.neab.net/locality/lainejau.htm, grube-lengenbach.ch, k1q.net, metalin.com, nrm.se, vstm.at, wsu.edu, outokumpu.fi, zinngrube.de. These were supplemented by data from gl.rhbnc.ac.uk/geode. Comparable to mindat.org, webmineral.com provides a vast amount of detailed mineralogical, geochemical, and optical data; specific mineral descriptions derived from un2sg4.unige.ch/athena, miner.ch, rruff.geo.arizona.edu, duke.edu, gov.mb.ca, as well as from various museums assembled at euromin.w3sites.net (for precise links see “Bibliography/Electronic Media” on page 870).

XVIII

Mineral Descriptions

Goethite lining vug in coronadite, Broken Hill, Australia

1


Explanations & Abbreviations The mineral names reflect the naming of by the International Mineralogical Association (IMA), wherever possible, and are printed in bold in the index section. Synonyms Synonyms (and outdated names) are provided in brackets immediately behind the mineral name, they are printed in italics in the index section. Geologic Typical geological settings are presented for each mineral, although in many cases, Environment these do not cover all possible genetic conditions. Reflection This is the mineral’s colour in reflected light (without polarisers) as observed on an Colour untarnished surface; it occasionally differs from the handspecimen, which may show internal reflections that contribute to the overall colour impression (even for ore minerals, this is sometimes the case under the microscope). Cleavage and cracks in the observed mineral or phase boundaries between adjacent Internal minerals can result in reflections within semi-transparent or translucent minerals. Reflections Reflectance Reflectance relates to the percentage of light that is reflected from the mineral’s surface relative to the initial beam. Literature data were recalculated to 589 nm for direct comparison of all data (observation wave lengths vary considerably from one publication to the next). When minimum - maximum values are provided, they show the range found for different optical axes in cases of optical anisotropic. Values without decimal places and in square brackets (e.g., [35]) are visual estimates on the basis of photo comparisons (i.e., taken with the same camera setting) and reflection data of 6 well-known minerals; wherever possible, these estimates were made with minerals of similar tints. Tests showed errors ranging between 2 and 5 percent points (e.g. 38% instead of the documented 35%); occasionally, this error may be larger (in particular within fine-grained materials). Bireflectance is an optical effect (see also pleochroism), where the reflectance chanBireflectance ges when the sample is rotated while illuminated by plane polarised light. The polarisers are not crossed (preferably the polariser is taken out) to observe bireflectance. Isotropic minerals, such as pyrite or galena, do not show bireflectance. Anisotropic minerals possess differences in physical properties (e.g., hardness, reAnisotropy fractive index, density, etc.) along different crystallographic axes. Here, anisotropy either results in different grey shades or colours, when the sample is rotated and observed under crossed nicols (polariser + analyser). Occasionally, it is necessary to slightly open the analyser in order to judge anisotropy. Isotropic minerals, such as pyrite or galena, generally do not show anisotropy (although some exceptions are known and also documented in this atlas: see galena, for instance). Pleochroism describes a mineral’s ability to absorb/reflect light of different wavePleochroism lengths depending on the crystallographic orientation of the sample. This results in a colour change when the specimen is rotated (under parallel nicols). Pleochroism is the general term that includes dichroism in uniaxial (one optical axis) and trichroism in biaxial (two optical axes) crystals. I/A.01-10 These are the Strunz classification symbols for the respective mineral. Hermann-Mau- Wherever a precise Hermann-Maugin symbol for the respective mineral has not yet gin Symbols for been determined, the class is given as stated below: Crystallographic tri. = triclinic trig. = trigonal Classes mono. = monoclinic ortho. = orthorhombic tet. = tetragonal hex. = hexagonal cub. = cubic (isometric) [a - o] The letters correspond to individuals and/or institutions providing polished sections for examination and presentation (referenced on page XV). Nic. //, Nic.+ The nicols (polariser & analyser) are parallel (//) or crossed (+, exact alignment). However, in reflected light microscopy, the analyser is occasionally rotated a few degrees (denoted as (+2°) from its ideal position to emphasise anisotropy effects. Mineral Name

3

Copper (Cuivre, Kupfer) Geologic Environment:

Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

basic Precambrian magmatites, at border between oxidation and cementation zone, cap rocks of Cu sulfide veins, volcanic and sedimentary rocks pink-white 92.20 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.01-Copper, Silver and Gold Series I/A.01-10 Copper I/A.01-15 Allabogdanite I/A.01-20 Silver I/A.01-40 Gold I/A.01-50 Auricupride I/A.01-60 Tetraauricupride I/A.01-65 Bogdanovite I/A.01-68 Hunchunite I/A.01-70 Anyuiite

Cu (Fe,Ni)2P Ag Au Cu3Au AuCu (Au,Te,Pb)3(Cu,Fe) (Au,Ag)2Pb Au(Pb,Sb)2

– 4/m 3 2/m 2/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m

Descriptions A Skeletal copper (light pink) with small specs of cuprite (bluish grey); Broken Hill, Australia [c]; Nic. // B Anhedral native copper (pink tint) next to domeykite (grey) in jasper; Çayeli, NE Turkey [n]; Nic. // C Anhedral native copper (dark; scratches) next to domeykite (almost black) in jasper (red internal reflections); Çayeli, NE Turkey [n]; Nic. +

4

Copper A

60 μ

C

B

125 μ

125 μ

5

Silver Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal sulfide veins bright silver white 82.82 Bireflectance: (87.5 antimonian) isotropic, scratches give impression of anisotropy


A B C

D E



Descriptions Anhedral silver (white) in galena (light grey), thin reaction rim of argentite (greenish grey); Monte Narba, Sardinia, Italy [b]; Nic. // Anhedral silver (medium grey, many scratches) in galena (dark, some scratches); Monte Narba, Sardinia, Italy [b]; Nic. + Myrmekitic intergrowth of native silver (white), chalcopyrite (olive), and cabriite (pinkish cream, slight bireflectance), niggliite (here greenish cream), geversite (blue grey), galena (medium grey); Oktjabrsky, Norilsk, GUS [d]; Nic. // Fine-grained aggregates of “knitted” silver (white), galena (medium grey), carbonate matrix (dark grey); Brand-Erbisdorf, Saxony, Germany [g]; Nic. // Silver (isotropic), galena (isotropic), carbonates (white and brownish internal reflections); Brand-Erbisdorf, Saxony, Germany [g]; Nic. +

6

Silver A

60 μ

C

B

125 μ

47 μ

D

E

50 μ

50 μ 7

Gold (Ag-rich Gold = Electrum, Oro) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:

Anisotropy: Pleochroism:

quartz veins, alluvial deposits gold-yellow, silver-white (Ag) to copper-red (Cu) blue and green (transmitted light), otherwise opaque 72.26 Bireflectance: (92.3 Electrum, 66.6 palladian) isotropic, many scratches suggest otherwise


A B C D E



Descriptions Irregular patches of gold (yellow) in pyrite (light cream); West Driefontein, Johannesburg, South Africa [c]; Nic. // Irregular gold grain (yellow) between stibnite (light grey); Murchison Range, South Africa [g]; Nic. // Anhedral electrum (yellowish white), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. // Anhedral electrum (yellowish white), argentite (greenish grey), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. // Anhedral electrum (yellowish white), pyrite (cream) altered to goethite (bluish grey shades), quartz (dark grey); New Bullfrog mine, Nye Co., Nevada, USA [h]; Nic. //

8

Gold A

60 μ

C

B

125 μ

20 μ

D

E

20 μ

13 μ 9

Auricupride Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low temperature un-mixing of Au-Cu alloys violet rose [65] isotropic

Bireflectance:




Descriptions A Subhedral auricupride (bright orange) in nickeline matrix (slight pinkish brown anisotropy); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. // B Subhedral auricupride grain (bright orange) with core of native gold (yellow), nickeline matrix (brownish grey), skutterudite (light grey, lower right corner); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. //

10

Auricupride A

10 μ

B

3μ 11

Amalgam (Kongsbergite, Mercury Silver, Silver Amalgam) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal grey [35] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.02-Mercury and Amalgame series I/A.02-10 Mercury I/A.02-20 Kolymite I/A.02-22 Belendorffite I/A.02-28 Eugenite I/A.02-30 Amalgam I/A.02-40 Luanheite I/A.02-50 Schachnerite I/A.02-60 Paraschachnerite I/A.02-70 Goldamalgam I/A.02-80 Weishanite I/A.02-90 Potarite I/A.02-100 Leadamalgam

Hg Cu7Hg6 Cu7Hg6 Ag9Hg2 Ag2Hg3 Ag3Hg Ag1.1Hg0.9 Ag3Hg2 (Au,Ag)Hg (Au,Ag)3Hg2 PdHg HgPb2

– 3 2/m – 43m 3m – 43m – 4/m 3 2/m 6/m 2/m 2/m 6/m 2/m 2/m 2/m 2/m 2/m – 4/m 3 2/m 6/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Rim of amalgam (medium grey) replacing pyrite (tinted white), goethite (dark grey); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. // B Amalgam (dark grey), pyrite (isotropic, brownish grey), goethite (dark grey, some brown internal reflections); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. +

12

Amalgam A

5μ

B

12 μ 13

Aluminium Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low oxygen fugacity environments; Tolbachik volcano, Kamchatka, Russia white [> 70] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.03-Aluminium-Khatyrkite series I/A.03-05 Aluminum I/A.03-10 Cupalite I/A.03-20 Khatyrkite

Al (Cu,Zn)Al (Cu,Zn)Al2

– 4/m 3 2/m ortho. 4/m 2/m 2/m

Descriptions A Anhedral native aluminium (light grey, “grainy” appearance); mud volcano, Caspian Sea near Baku, Azerbaidzhan [h]; Nic. // B Native aluminium (fine multicolour reflections); mud volcano, Caspian Sea near Baku, Azerbaidzhan [h]; Nic. +

14

Aluminium A

60 μ

B

60 μ 15

Cadmium Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Ust'-Khannin gabbro intrusive tin white with bluish tint [60]

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.04-Zinc-Cadmium series I/A.04-10 Zinc I/A.04-15 Brass I/A.04-20 Zhanghengite I/A.04-30 Danbaite I/A.04-40 Cadmium

Zn Cu3Zn2 (Cu,Zn,Fe,Al,Cr) CuZn2 Cd

6/m 2/m 2/m cub. – 4/m 3 2/m cub. 6/m 2/m 2/m

Descriptions A Rounded grain of native cadmium (white, many scratches); West Verkhoyansky Range, Siberia, Russia [h]; Nic. // B Rounded grain of native cadmium (dark brownish grey, many scratches); West Verkhoyansky Range, Siberia, Russia [h]; Nic. +

16

Cadmium A

60 μ

B

60 μ 17

Lead (Plumbum) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, placers, possibly authigenic processes, replacement of tree roots medium grey with brownish tint rare, brownish-red 50.67 Bireflectance: isotropic, but also anomalous dark to bluish grey anisotropy

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.05-Lead series I/A.05-10 I/A.05-20 I/A.05-30

Indium Lead Tin

In Pb Sn

4/m 2/m 2/m – 4/m 3 2/m 4/m 2/m 2/m

Descriptions A Anhedral native lead (medium grey with brownish tint, translation lamellae; also compare with freshly polished lead in litharge sample - photo A), dolomite (dark grey); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. // B Native lead (isotropic parts and anomalous brownish to bluish grey anisotropy), dolomite (milky internal reflections); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. + C Small grain of native lead (dark with brown internal reflections), dolomite matrix (bright internal reflections); Harstigen Mine, Pajsberg, Filipstad, Värmland, Sweden [j]; Nic. +

18

Lead A

120 μ

C

B

250 μ

26 μ

19

Iron (Eisen) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

meteorites, rarely in basalts which intruded carbon-rich sediments white 58.07 (58.6 nickelian) isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.07-Iron series I/A.07-10 I/A.07-20 I/A.07-30

Iron Kamacite Wairauite

Fe alpha-(Fe,Ni) CoFe

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Network of native iron (light grey) in silicate matrix (dark grey); Ovifak, W-Greenland [e]; Nic. // B Anhedral iron (light grey) with goethite rim (various darker grey shades), ilmenite (brownish pleochroism), silicates (dark grey); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. // C Iron (dark grey), goethite (dark grey), ilmenite (bluish grey anisotropy), silicates (brown and multicolour internal reflections); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. +

20

Iron A

239 μ

C

B

99 μ

99 μ

21

Kamacite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Fe meteorites medium grey with brownish tint [20] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.07-Iron series I/A.07-10 I/A.07-20 I/A.07-30

Iron Kamacite Wairauite

Fe alpha-(Fe,Ni) CoFe

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Massive kamacite (medium grey, main mineral) with seams of taenite (medium grey) and unidentified mineral (same grey shade as taenite); Meteorite, locality unknown [d]; Nic. // B Kamacite (dark grey, isotropic), taenite (almost black), unidentified mineral (brown internal reflections); Meteorite, locality unknown [d]; Nic. +

22

Kamacite A

40 μ

B

40 μ 23

Taenite (Antitaenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

meteorites dark grey [7] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.08-Nickel series I/A.08-10 I/A.08-20 I/A.08-30 I/A.08-40 I/A.08-50

Nickel Taenite Tetrataenite Awaruite Jedwabite

Ni gamma-(Fe,Ni) FeNi Ni2Fe to Ni3Fe Fe7(Ta,Nb)3

– 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m – 4/m 3 2/m 6mm

Descriptions A Anhedral mass and myrmekitic taenite (medium grey) in kamacite (light grey), partial oxidation of taenite to goethite (slightly bluish grey in massive material); Meteorite, locality unknown [d]; Nic. // B Taenite (black), kamacite (lighter grey), goethite (brown internal reflections); Meteorite, locality unknown [d]; Nic. +

24

Taenite A

60 μ

B

60 μ 25

Awaruite (Bobrovskite, Josephinite, Souesite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

fluviatil placers, serpentinised peridotites, meteorites tinted grey 64.98 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.08-Nickel series I/A.08-10 I/A.08-20 I/A.08-30 I/A.08-40 I/A.08-50

A B C D E

Nickel Taenite Tetrataenite Awaruite Jedwabite

Ni gamma-(Fe,Ni) FeNi Ni2Fe to Ni3Fe Fe7(Ta,Nb)3

– 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m – 4/m 3 2/m 6mm

Descriptions Anhedral awaruite (white) and heazlewoodite (slight yellow tint) enclosed by magnetite (medium grey), silicates (dark grey); Oko, NE of Koti, Shikoku, Japan [j]; Nic. // Irregular intergrowth of awaruite (slightly tinted light grey) with goethite (dark grey) and silicates (dark grey); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. // Awaruite (dark greys, faint anisotropy), goethite (brown internal reflections), silicates (colourless); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. + Massive awaruite (slightly tinted grey) with inclusions of oregonite (slightly pinkish), silicates and goethite (dark grey); Canyon Creek Trail, Josephine Co., Oregon, USA [j]; Nic. // Anhedral awaruite (white) next to chromite (medium grey) and magnetite (slightly lighter grey), silicates (dark grey); Keeps Mine, Wyangle, Tumut, New South Wales, Australia [j]; Nic. //

26

Awaruite A

19 μ

C

B

125 μ

125 μ

D

E

125 μ

50 μ 27

Cohenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Fe meteorites, terrestrial Fe from mafic rocks (assimilation of graphite) cream-white 57.67 - 59.62 slight

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.09-Honquiite-Tantalcarbide series I/A.09-10 Hongquiite I/A.09-20 Khamrabaevite I/A.09-30 Tongbaite I/A.09-35 Isovite I/A.09-40 Haxonite I/A.09-50 Cohenite I/A.09-55 Niobocarbide I/A.09-60 Tantalcarbide

TiO (Ti,V,Fe)C Cr3C2 (Cr,Fe)23C6 (Fe,Ni)23C6 (Fe,Ni,Co)3C (Nb,Ta)C TaC

– 4/m 3 2/m – 4/m 3 2/m 2/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m 2/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Large patches and lamella of cohenite (slightly more cream than iron) between and in native iron grains (white, almost bluish in comparison), goethite (medium grey, dendritic) as oxidation product; Ovifak, W-Greenland [e]; Nic. // B Vermiform cohenite (slightly brighter than iron, cream) in native iron (white); Ovifak, WGreenland [e]; Nic. // C Lamellar cohenite (slightly cream) in native iron (white) largely replaced by goethite (large medium grey patches); Ovifak, W-Greenland [e]; Nic. //

28

Cohenite A

60 μ

C

B

20 μ

125 μ

29

Carlsbergite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

inclusions in kamacite and troilite, Fe meteorites light grey with a rose-violet tint 41.00 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.10-Osbornite-Sinoite series I/A.10-10 Osbornite I/A.10-20 Carlsbergite I/A.10-30 Roaldite I/A.10-40 Siderazot I/A.10-45 Nierite I/A.10-50 Sinoite

TiN CrN (Fe,Ni)4N Fe5N2 Si3N4 Si2N2O

– 4/m 3 2/m – 4/m 3 2/m – 43m 622 3m mm2

Descriptions A Irregular carlsbergite grain (light grey) in kamacite (tinted white); Kenton County Meteorite, Kentucky, USA [h]; Nic. //

30

Carlsbergite A

5μ

31

Sinoite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphism of EL6 chondrites or impact melting of EL4 chondrites dark to medium grey milky [12] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.10-Osbornite-Sinoite series I/A.10-10 Osbornite I/A.10-20 Carlsbergite I/A.10-30 Roaldite I/A.10-40 Siderazot I/A.10-45 Nierite I/A.10-50 Sinoite

TiN CrN (Fe,Ni)4N Fe5N2 Si3N4 Si2N2O

– 4/m 3 2/m – 4/m 3 2/m – 43m 622 3m mm2

Descriptions A Anhedral grain of sinoite (medium grey); Pillistfer Enstatite-Chondrite, Estonia [h]; Nic. // B Sinoite (milky internal reflections); Pillistfer Enstatite-Chondrite, Estonia [h]; Nic. +

32

Sinoite A

12 μ

B

12 μ 33

Schreibersite (Lamprite, Partschite, Rhabdite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

octahedrite meteorites, rare in basalts light cream [52] Bireflectance: brownish grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.11-Barringerite-Schreibersite series I/A.11-05 Florenskyite I/A.11-10 Barringerite I/A.11-20 Schreibersite I/A.11-30 Nickelphosphide

(Fe,Ni)TiP (Fe,Ni)2P (Fe,Ni)3P (Ni,Fe)3P

2/m 2/m 2/m 6 m2 – 4 – 4

Descriptions A Interstitial schreibersite (light cream tint, here outlined by goethite (?) at suture) in native iron (light grey), silicates (dark grey); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. // B Schreibersite (brownish grey anisotropy), native iron (medium grey), silicates (brown internal reflections); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. +

34

Schreibersite A

24 μ

B

24 μ 35

Gupeiite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

extraterrestrial origin and concentrated in placers cream-white 53,40 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.12-Perryite-Ferdisilicite series I/A.12-10 Perryite I/A.12-20 Suessite I/A.12-30 Gupeiite I/A.12-35 Hapkeite I/A.12-40 Xifengite I/A.12-50 Fersilicite I/A.12-60 Ferdisilicite

(Ni,Fe)8(Si,P)3 (Fe,Ni)3Si Fe3Si Fe2Si Fe5Si3 FeSi FeSi2

3m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 6/m 2/m 2/m 23 4/m 2/m 2/m

Descriptions A Anhedral exsolution of gupeiite (lightest mineral, cream-white) and fersilicite (darkest mineral) in xifengite (light cream); Isovskaja Field, Priasovje, Ukraine [h]; Nic. //

36

Gupeiite A

11 μ

37

Xifengite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

apparently extraterrestrial, in placers light cream 46.20 - 44.90 Bireflectance: moderate, bluish to brownish grey



3m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 6/m 2/m 2/m 23 4/m 2/m 2/m

Descriptions A Anhedral grain of xifengite (very light cream) with inclusions of gupeiite (slightly lighter than xifengite) and fersilicite (slightly darker than xifengite); Isovskaja Field, Priasovje, Ukraine [h]; Nic. // B Xifengite (brownish grey anisotropy), gupeiite (similar shade as xifengite), fersilicite (slightly darker grey than xifengite); Isovskaja Field, Priasovje, Ukraine [h]; Nic. +

38

Xifengite A

15 μ

B

27 μ 39

Fersilicite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

presumably extraterrestrial origin, concentrated in placers and sandstones of the Poltava series light grey [40]

Bireflectance:



3m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 6/m 2/m 2/m 23 4/m 2/m 2/m

Descriptions A Anhedral exsolution of fersilicite (darkest mineral, light grey) and gupeiite (lightest mineral) in xifengite (light cream); Isovskaja Field, Priasovje, Ukraine [h]; Nic. //

40

Fersilicite A

11 μ

41

Hexaferrum Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

chromite segregations in dunite white [67] Bireflectance: slightly brownish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.13-Osmium series I/A.13-10 Rhenium I/A.13-15 Hexaferrum I/A.13-20 Osmium I/A.13-30 Ruthenium I/A.13-40 Rutheniridosmine

Re (Fe,Os,Ru,Ir) (Os,Ir) (Ru,Ir,Os) (Ir,Os,Ru)

6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m

Descriptions A Euhedral hexaferrum (white) in chromite (medium grey); Pole Corral Pass, Rattlesnake Creek Terrane, Beegum, California, USA [h]; Nic. // B Hexaferrum (brownish grey, slight anisotropy), chromite (isotropic, red brown internal reflections); Pole Corral Pass, Rattlesnake Creek Terrane, Beegum, California, USA [h]; Nic. +

42

Hexaferrum A

8μ

B

8μ 43

Osmium (Iridosmine, Nevyanakite, Rutheniridosmium, Siserskite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic segregations and placers from ultrabasic rocks light grey with bluish tint 63.32 - 65.57 Bireflectance: weak to moderate




Descriptions A Osmium (light grey) in laurite (medium grey) and intergrown with rhodarsenide (light olive), next to large grain of isoferroplatinum (light cream); Maandagshoek, South Africa [d]; Nic. // B Osmium (darker brown), laurite (dark), rhodarsenide (similar to isoferroplatinum; olive), isoferroplatinum (brownish grey); Maandagshoek, South Africa [d]; Nic. +

44

Osmium A

7μ

B

7μ 45

Ruthenium Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers from ultrabasic rocks white with a creamy tint [80] weak

Bireflectance:




Descriptions A In order to show the lamellar ruthenium (bright network) contained in isoferroplatinum (slightly darker), the aperture was almost closed, leading to much darker appearance. At the upper right rim: nickelferroplatinum (same brightness as ruthenium, but larger as lamellae); Maandagshoek, South Africa [d]; Nic. // B Ruthenium (network of dark streaks), isoferroplatinum (slightly brighter), nickelferroplatinum (shade between both other minerals); Maandagshoek, South Africa [d]; Nic. +

46

Ruthenium A

24 μ

B

24 μ 47

Rutheniridosmine Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers from ultrabasic rocks light cream 67.80 Bireflectance: weak, sometimes with wavy extinction, colours tinged with orange weak to absent




Descriptions A Large aggregate of rutheniridosmine (light cream, well developed cleavage) with crystallographically oriented inclusions of isoferroplatinum (lightest cream), fine-grained cooperite (light grey, on cracks/cleavage), unnamed alloy ((Pt, Ir, Ru, Os); white, long platelets); Pekulney Massif, NE Russia [h]; Nic. // B Rutheniridosmine (dark brownish grey), isoferroplatinum (slightly lighter than rutheniridosmine), cooperite (mottled grey anisotropy), unnamed alloy (brownish grey to bluish anisotropy); Pekulney Massif, NE Russia [h]; Nic. +

48

Rutheniridosmine A

60 μ

B

60 μ 49

Iridium Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

exsolutions in Pt-Fe alloys white 72.14 (74.9 ruthenian) isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.14-Platinum series I/A.14-10 Rhodium I/A.14-20 Palladium I/A.14-30 Iridium I/A.14-70 Platinum I/A.14-80 Yixunite I/A.14-85 Damiaoite I/A.14-90 Hongshiite I/A.14-100 Skaergaardite

(Rh,Pt) Pd,Pt (Ir,Os,Ru,Pt) Pt Pt3In PtIn2 PtCu CuPd

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 3 2/m – 4/m 3 2/m

Descriptions A Euhedral iridium inclusions (white) in isoferroplatinum (slightly tinted white), partial rim of cuproiridsite (medium grey) in lower section of grain; Inagly Massif, Aldan Shield, Russia [h]; Nic. // B Euhedral iridium inclusions (white) in isoferroplatinum (slightly tinted white); Inagly Massif, Aldan Shield, Russia (almost closed aperture; therefore, minerals appear darker than in photo above) [h]; Nic. //

50

Iridium A

60 μ

B

10 μ 51

Platinum (Polyxen) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

grains and nuggets in alluvial deposits cream-white 65.16 isotropic

Bireflectance:




Descriptions A Porous grain of native platinum (cream-white) as rim around cooperite (light grey); Maandagshoek, South Africa [d]; Nic. // B Native platinum (strongly scratched, dark brownish grey), cooperite core (dark grey anisotropy); Maandagshoek, South Africa [d]; Nic. +

52

Platinum A

24 μ

B

24 μ 53

Hongshiite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

apatite-bearing actinolised diopsidite white with pinkish tint 65.80 - 63.8 Bireflectance: weak to moderate, dull grey to dull reddish brown




Descriptions A Anhedral hongshiite (pinkish tint) and palladodymite (brownish grey, darkest mineral) as inclusions in rutheniridosmine matrix (white with slight yellow tint); Miass, Urals, Russia [h]; Nic. / /

54

Hongshiite A

5μ

55

Isoferroplatinum Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt-Fe and Cu-Ni deposits in ultramafics and related placers light cream [77] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.15-Isoferroplatinum-Ferronickelplatinum series I/A.15-05 Chengdeite Ir3Fe I/A.15-10 Isoferroplatinum (Pt,Pd)3(Fe,Cu) I/A.15-20 Tetraferroplatinum PtFe I/A.15-30 Tulameenite Pt2FeCu I/A.15-40 Ferronickelplatinum Pt2FeNi

– 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Subhedral isoferroplatinum (light cream) intergrown with unnamed Pt-Rh-Ru-Fe alloy (slightly lighter than isoferroplatinum) and laurite (medium grey); Maandagshoek, South Africa [d]; Nic. // B Anhedral isoferroplatinum (lightest cream), crystallographically oriented in rutheniridosmine (weak grey, well-developed cleavage), cooperite (light grey, on cleavage/cracks); Pekulney Massif, NE Russia [h]; Nic. //

56

Isoferroplatinum A

24 μ

B

60 μ 57

Tulameenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt placers white 61.50 - 65.50 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.15-Isoferroplatinum-Ferronickelplatinum series I/A.15-05 Chengdeite Ir3Fe I/A.15-10 Isoferroplatinum (Pt,Pd)3(Fe,Cu) I/A.15-20 Tetraferroplatinum PtFe I/A.15-30 Tulameenite Pt2FeCu I/A.15-40 Ferronickelplatinum Pt2FeNi

– 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Tulameenite (white) intergrown with oulankaite (slightly darker cream platelet) and telargpalite (cream, here lighter than oulankaite), chalcopyrite (yellow), silicates (dark grey); Lukkulaisvaara, N Karelia, Russia [h]; Nic. // B Tulameenite (dark), oulankaite (undulating cream to brown anisotropy), telargpalite (brownish grey), chalcopyrite (bluish grey), silicates (multicolour internal reflections); Lukkulaisvaara, N Karelia, Russia [h]; Nic. +

58

Tulameenite A

9μ

B

9μ 59

Atokite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

PGE concentrates from mafic/ultramafic rocks light cream [65] Bireflectance: isotropic, but occasionally slightly anisotropic (strain) none to slight

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.16-Zvyagintsevite-Plumbopalladinite series I/A.16-10 Zvyagintsevite (Pd,Pt,Au)3(Pb,Sn) I/A.16-20 Atokite (Pd,Pt)3Sn I/A.16-30 Rustenburgite (Pt,Pd)3Sn I/A.16-40 Niggliite PtSn I/A.16-50 Stannopalladinite (Pd,Cu)2Sn2 I/A.16-60 Palarstanide Pd8(Sn,As)3 I/A.16-70 Plumbopalladinite Pd3Pb2

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 6/m 2/m 2/m 6/m 2/m 2/m 622 6/m 2/m 2/m

Descriptions A Anhedral atokite (white) in pyrrhotite (cream, slight bireflectance), magnetite (medium grey); Oktjabrsky, Norilsk, Russia [h]; Nic. // B Atokite (bluish grey), pyrrhotite (brownish grey, slight anisotropy), magnetite (isotropic); Oktjabrsky, Norilsk, Russia [h]; Nic. +

60

Atokite A

120 μ

B

120 μ 61

Niggliite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late hydrothermal veins cream to blue-grey 44.69 - 60.90 Bireflectance: strong strong, creamish brown to blue-black strong, cream to pale blue



Descriptions A Niggliite (brownish to blue anisotropy), cabriite (dark), geversite (dark), chalcopyrite (dark); Oktjabrsky, Norilsk, GUS [d]; Nic. + B Irregular niggliite (cream to blue-grey; strong bireflectance) in cabriite (pinkish brown, compare bireflectance with next photo), geversite (light grey), chalcopyrite (olive); Oktjabrsky, Norilsk, GUS [d]; Nic. // C Niggliite (cream to blue-grey; strong bireflectance), cabriite (pinkish brown, compare bireflectance with previous photo), geversite (light grey), chalcopyrite (olive); Oktjabrsky, Norilsk, GUS [d]; Nic. //

62

Niggliite A

60 μ

C

B

74 μ

74 μ

63

Stannopalladinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Cu-Ni sulfides intergrown with niggliite very slight pinkish tint 54.00 - 55.50 Bireflectance: strong, light brownish grey to lilac-red to grey-blue



Descriptions (very slight pinkish tint) in atokite (white); Oktjabrsky,

A Hexagonal stannopalladinite crystal Norilsk, Russia [h]; Nic. // B Stannopalladinite (light brownish grey), atokite (dark brownish grey); Oktjabrsky, Norilsk, Russia [h]; Nic. +

64

Stannopalladinite A

5μ

B

5μ 65

Palarstanide Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

massive cubanite, chalcopyrite, and talnakhite ores light grey 55.64 - 56.85 Bireflectance: dark grey to brownish grey



Descriptions A Euhedral palarstanide (light grey) surrounded by atokite (white) in a matrix of cubanite (brownish tint), magnetite (medium grey); Majak Mine, Talnakh, Urals, Russia [h]; Nic. // B Palarstanide (dark brown-grey), atokite (bluish to brownish grey anisotropy), cubanite (slightly darker than palarstanide; Majak Mine, Talnakh, Urals, Russia [h]; Nic. +

66

Palarstanide A

120 μ

B

120 μ 67

Plumbopalladinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Ni-Cu ores white with pink tint 54.49 - 57.51 Bireflectance: distinct, light to dark brown and orange hardly noticeable, brownish greys



Descriptions A Anhedral plumbopalladinite (pink tint) intergrown with oriented polarite (light grey, similar reflectivity), rim of isoferroplatinum (white), cubanite (greenish brown tint), pentlandite (creamish brown), valleriite (dark brownish and bluish grey pleochroism); Majak Mine, Talnakh Norilsk, Urals, Russia [h]; Nic. // B Plumbopalladinite (light to dark brown and orange anisotropy), polarite (light to dark brown anisotropy), isoferroplatinum (medium grey), cubanite (bluish grey anisotropy), pentlandite (brownish tinted grey), valleriite (light orange to grey anisotropy); Majak Mine, Talnakh Norilsk, Urals, Russia [h]; Nic. +

68

Plumbopalladinite A

60 μ

B

60 μ 69

Paolovite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Cu-Ni sulfides lilac-grey 51.71 - 55.99 reddish to brown

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/A.17-Paolovite-Taimyrite series I/A.17-10 Paolovite I/A.17-20 Cabriite I/A.17-30 Taimyrite I/A.17-40 Tatyanaite

Pd2Sn Pd2SnCu (Pd,Cu,Pt)3Sn (Pt,Pd,Cu)9Cu3Sn4

2/m 2/m 2/m 2/m 2/m 2/m ortho. ortho.

Descriptions A Anhedral paolovite (lilac-grey) in stannite (olive grey), chalcopyrite (greenish yellow); Majak Mine, Talnagh, Norilsk, Urals, Russia [h]; Nic. // B Paolovite (reddish to brown anisotropy), stannite (greenish greys anisotropy), chalcopyrite (greenish grey anisotropy); Majak Mine, Talnagh, Norilsk, Urals, Russia [h]; Nic. +

70

Paolovite A

60 μ

B

60 μ 71

Cabriite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

galena-chalcopyrite veins, massive mooihoekite ore pink with lilac tint 48.34 - 56.99 Bireflectance: strong, greyish brown to golden slight

slight




Descriptions A Cabriite (red brown to dark anisotropy), niggliite (large grains and lamellae in cabriite; strong cream to blue anisotropy), geversite (dark blue grey), chalcopyrite (dark), native silver (medium grey); Oktjabrsky, Norilsk, Russia [d]; Nic. + B Massive cabriite (pinkish cream, slight bireflectance, compare next photo) with fine, almost invisible lamellar intergrowths of niggliite (strong cream to blue bireflectance, also as larger anhedral grains), geversite (blue grey), chalcopyrite (olive), native silver (white); Oktjabrsky, Norilsk, Russia [d]; Nic. // C Cabriite (pinkish, slight bireflectance, compare previous photo), niggliite (strong cream to blue bireflectance), geversite (blue grey), chalcopyrite (olive), native silver (white); Oktjabrsky, Norilsk, Russia [d]; Nic. //

72

Cabriite A

60 μ

C

B

125 μ

125 μ

73

Taimyrite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

grains and veinlets in gabbro-dolerites greenish cream to brownish 48.44 - 52.68 Bireflectance: clearly visible dark grey with a blue tint to yellowish grey distinct, greenish to brownish




Descriptions A Taimyrite (slight greenish tint, bireflectance compare next picture, cleavage), magnetite (medium grey), pentlandite (yellow tint), chalcopyrite (yellow); Majak mine, Talnakh, GUS [d]; Nic. // B Taimyrite (brown tint, bireflectance compare previous picture, cleavage), magnetite (medium grey), pentlandite (yellow tint), chalcopyrite (yellow); Majak mine, Talnakh, GUS [d]; Nic. // C Taimyrite (bluish grey to brown anisotropy), magnetite (isotropic), pentlandite (bluish grey), chalcopyrite (blue); Majak mine, Talnakh, GUS [d]; Nic. + (+2°)

74

Taimyrite A

16 μ

C

B

36 μ

36 μ

75

Arsenic Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins slightly brownish grey 46.95 - 52.76 Bireflectance: distinct, yellow brown and light grey to yellowish grey feeble

Strunz Classification - Group Members - Chemical Formula - Crystallography I/B.01-Arsenic-Bismuth series I/B.01-10 Arsenic I/B.01-20 Stibarsen I/B.01-30 Antimony I/B.01-40 Bismuth I/B.01-50 Arsenolamprite I/B.01-55 Pararsenolamprite I/B.01-60 Paradocrasite

A B

C

D E

As SbAs Sb Bi As As Sb2(Sb,As)2

– 3 2/m – 3 2/m – 3 2/m – 3 2/m 2/m 2/m 2/m ortho. 2

Descriptions Native arsenic (cream, distinctive cleavage); Vater Abraham Mine, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. // Anhedral arsenic (light grey), antimony (white lower part), dyscrasite (cream tint), crust of safflorite (darker grey than arsenic) covered by pyrargyrite (blue grey); St. Andreasberg, Hartz Mts., Germany [f]; Nic. // Arsenic (brown grey), antimony (grey), dyscrasite (lighter brownish grey), safflorite (blue to brown to dark anisotropy), pyrargyrite (small red internal reflections); St. Andreasberg, Hartz Mts., Germany [f]; Nic. + Radial arsenic (grey with brownish tint) in matrix of antimony (slightly lighter grey); St. Andreasberg, Hartz Mts., Germany [e]; Nic. // Euhedral native arsenic (cream) overgrown by xanthoconite (bluish grey); Vater Abraham Mine, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. //

76

Arsenic A

40 μ

C

B

125 μ

125 μ

D

E

50 μ

250 μ 77

Antimony (Stibium) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins white 68.82 - 70.71 weak very week

Bireflectance:



– 3 2/m – 3 2/m – 3 2/m – 3 2/m 2/m 2/m 2/m ortho. 2

Descriptions A Botryoidal antimony (medium grey) with interstitial arsenic patches (slightly darker grey in lower section); St. Andreasberg, Hartz Mts., Germany [e]; Nic. // B Anhedral antimony (white, scratched) below safflorite crust (light grey); St. Andreasberg, Hartz Mts., Germany [f]; Nic. // C Antimony (grey) below safflorite crust (blue to brown to grey anisotropy); St. Andreasberg, Hartz Mts., Germany [f]; Nic. +

78

Antimony A

60 μ

C

B

125 μ

125 μ

79

Bismuth Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Co-Ni-Ag-Sn ores, pegmatites, topaz-Sn-W veins white, brilliant creamy 65.35 - 66.65 distinct feeble

Bireflectance:



– 3 2/m – 3 2/m – 3 2/m – 3 2/m 2/m 2/m 2/m ortho. 2

Descriptions A Skeletal bismuth (pinkish white, strongly scratched) in safflorite (white); Schneeberg, Germany [b]; Nic. // B Twin lamellae in native bismuth (yellowish to blue grey anisotropy); Huallatani Mine, Bolivia [c]; Nic. + C Twinned skeletal bismuth (distinct anisotropy along twin suture) in safflorite (brown to blue anisotropy); Schneeberg, Germany [b]; Nic. +

80

Bismuth A

107 μ

C

B

80 μ

250 μ

81

Arsenolamprite (Hypotyphite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins light grey 42.66 - 47.87 weak

Bireflectance:


A B C D

E


– 3 2/m – 3 2/m – 3 2/m – 3 2/m 2/m 2/m 2/m ortho. 2

Descriptions Aggregate of arsenolamprite (light grey, cleavage), arsenic (slightly darker grey, finely dispersed), carbonate (dark grey); Marienberg, Saxony, Germany [j]; Nic. // Radially oriented arsenolamprite (light grey, cleavage), arsenic (slightly darker grey, finely dispersed), carbonate (dark grey), goethite (dark grey); Marienberg, Saxony, Germany [j]; Nic. // Arsenolamprite (blue to brownish anisotropy), arsenic (too fine to identify anisotropy), carbonate (dark), goethite (brown internal reflections); Marienberg, Saxony, Germany [j]; Nic. + Acicular arsenolamprite (light grey) and safflorite (white) in calcite (dark grey) and goethite (dark grey); Schwarzenthal, Krkonose Mts., Hradec Králové Region, Bohemia, Czech Republic [j]; Nic. // Arsenolamprite (dark grey, slight anisotropy), safflorite (blue and brown anisotropy), calcite (light internal reflections), goethite (reddish brown internal reflections); Schwarzenthal, Krkonose Mts., Hradec Králové Region, Bohemia, Czech Republic [j]; Nic. +

82

Arsenolamprite A

120 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 83

Graphite (Tremenbeerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed limestones, organic-rich shales, coal beds medium to dark grey 7.45 - 21.48 Bireflectance: very high extreme, light brownish grey to dark grey strong, grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography I/B.02-Carbon series, Graphite-Lonsdaleite I/B.02-10 Graphite I/B.02-20 Chaoite I/B.02-30 Moissanite I/B.02-40 Diamond I/B.02-50 Lonsdaleite

A B C D

E

C C SiC C C

6/m 2/m 2/m 6/m 2/m 2/m 6mm – 4/m 3 2/m 6/m 2/m 2/m

Descriptions Tectonically stressed graphite (medium to darker grey) with undulating grains, strong bireflectance; Kropfmühl, Germany [c]; Nic. // Graphite (strong yellowish to dark grey anisotropy); Kropfmühl, Germany [c]; Nic. + Spherular graphite (mottled brownish grey, bireflectance) in augite (dark grey), other silicates (mottled dark grey); Walker Mine, Buckingham Township, Québec, Canada [a]; Nic. // Spherular graphite (mottled brownish grey, bireflectance), pyrite rim (cream), small inclusions of magnetite (medium grey), silicates (mottled dark grey); Walker Mine, Buckingham Township, Québec, Canada [a]; Nic. // Graphite (mottled brownish to grey anisotropy), pyrite (isotropic), magnetite (isotropic), silicates (milky to multicolour internal reflections); Walker Mine, Buckingham Township, Québec, Canada [a]; Nic. +

84

Graphite A

120 μ

C

B

250 μ

125 μ

D

E

66 μ

66 μ 85

Sulfur Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

fumaroles, sedimentary (bacterial reduction of sulfates), oxidation of sulfides dark grey white to yellow [12] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography I/B.03-Sulfur-Selenium series I/B.03-10 Sulfur I/B.03-20 Rosickyite I/B.03-30 Selenium I/B.03-40 Tellurium

S8 S Se Te

2/m 2/m 2/m 2/m 32 32

Descriptions A Fine-grained sulfur (whitish internal reflections) cementing volcanic glass (brown internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + B Massive sulfur (strong relief due to low hardness, darker grey) with incorporated volcanic ash fragments (slightly lighter than sulfur and better polish); Akan National Park, Hokkaido, Japan [c]; Nic. // C Sulfur (bright yellow internal reflections), volcanic ash fragments (dark brown and white); Akan National Park, Hokkaido, Japan [c]; Nic. +

86

Sulfur A

120 μ

C

B

250 μ

250 μ

87

Selenium Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sublimation product of fumarolic vapours, precipitate from fluids in sandstone U and U-V deposits medium bluish to brownish grey red-brown 25.07 - 33.86 Bireflectance: weak strong, though not always visible, blue to brown


S8 S Se Te

2/m 2/m 2/m 2/m 32 32

Descriptions A Native selenium (brownish grey) as alteration rim at contact between clausthalite (light grey) and cerussite (darker grey, bireflectance),; Eskaborner Berg, Tilkerode, Germany [g]; Nic. // B Selenium (very fine-grained, blue to brown anisotropy), tiemannite (dark), cerussite (white internal reflections), hematite needles (red internal reflections); Eskaborner Berg, Tilkerode, Germany [g]; Nic. + C Native selenium (black, brown internal reflections), freboldite (brownish to bluish anisotropy, lamellar twinning); artificial [j]; Nic. +

88

Selenium A

24 μ

C

B

125 μ

50 μ

89

Tellurium (Silvan) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins white 56.33 - 67.93 Bireflectance: distinct, brownish greys faint


S8 S Se Te

2/m 2/m 2/m 2/m 32 32

Descriptions A Native tellurium (white) intergrown with coloradoite (light grey), euhedral pyrite (cream), quartz (dark grey); Kalgoorlie, Western Australia, Australia [j]; Nic. // B Intergrowth of native tellurium (cream-white) and goldfieldite (medium grey), bismuthinite (bluish grey, slight bireflectance); Mohawk Mine, Goldfield District, Esmeralda Co., Nevada, USA [j]; Nic. // C Native tellurium (brownish grey anisotropy), goldfieldite (dark), bismuthinite (bluish to brownish anisotropy); Mohawk Mine, Goldfield District, Esmeralda Co., Nevada, USA [j]; Nic. +

90

Tellurium A

120 μ

C

B

66 μ

66 μ

91

Algodonite (Whitneyite, Darwinite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal bright cream-white 65.06 weak

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.01-Algodonite-Cuprostibite series II/A.01-10 Algodonite II/A.01-20 Domeykite II/A.01-30 Horsfordite II/A.01-40 Kutinaite II/A.01-50 Koutekite II/A.01-60 Novakite II/A.01-70 Cuprostibite

A B C D E

Cu6As Cu3As Cu5Sb Cu14Ag6As7 Cu5As2 (Cu,Ag)21As10 Cu2(Sb,Tl)

6/m 2/m 2/m – 43m cub. – 4/m 3 2/m 6/m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions Partial to full replacement of algodonite (yellow tint) by unidentified mineral (light greenish grey); Houghton Co., Michigan, USA [g]; Nic. // Anhedral algodonite (yellow tint), native copper (bright pink), quartz (dark grey); Talmessi, Anarak, Iran [a]; Nic. // Algodonite (mottled dark greenish grey), native copper (brownish grey, bright scratches), quartz (milky internal reflections); Talmessi, Anarak, Iran [a]; Nic. + Anhedral algodonite (yellow tint), goethite (bluish grey), quartz (dark grey); Talmessi, Anarak, Iran [a]; Nic. // Algodonite (dark greenish grey), goethite (yellow to brown internal reflections), quartz (colourless internal reflections); Talmessi, Anarak, Iran [a]; Nic. +

92

Algodonite A

60 μ

C

B

50 μ

50 μ

D

E

50 μ

50 μ 93

Domeykite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal steel grey, tarnishes to yellowish, brownish, and iridescence 53.34

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.01-Algodonite-Cuprostibite series II/A.01-10 Algodonite II/A.01-20 Domeykite II/A.01-30 Horsfordite II/A.01-40 Kutinaite II/A.01-50 Koutekite II/A.01-60 Novakite II/A.01-70 Cuprostibite

A

B C D E

Cu6As Cu3As Cu5Sb Cu14Ag6As7 Cu5As2 (Cu,Ag)21As10 Cu2(Sb,Tl)

6/m 2/m 2/m – 43m cub. – 4/m 3 2/m 6/m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions Massive domeykite (greenish grey, rectangular to curved fractures) intergrown with galena (light grey), chalcopyrite (yellow), carbonate (dark grey); Dolores I Mine, Chañarcillo, Copiapó Province, Chile [a]; Nic. // Anhedral domeykite as fissure filling (medium grey) and small grains of native copper (reddish tint) in jasper; Çayeli, NE Turkey [n]; Nic. // Domeykite (dark) and small grains of native copper (dark) in jasper (red internal reflections); Çayeli, NE Turkey [n]; Nic. + Anhedral domeykite (greenish grey) intergrown with safflorite (cream), pyrargyrite (blue grey), carbonate (dark grey); Dolores I Mine, Chañarcillo, Copiapó Province, Chile [a]; Nic. // Domeykite (dark grey), safflorite (strong blue to brown anisotropy), pyrargyrite (red internal reflections, anisotropic), carbonate (milky internal reflections); Dolores I Mine, Chañarcillo, Copiapó Province, Chile [a]; Nic. +

94

Domeykite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 95

Dyscrasite (Antimonsilver, Stibioargentite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

some hydrothermal Ag deposits slight cream tint, tarnishing to lead-grey, yellowish, or black 59.67 - 63.00 Bireflectance: weak, light brownish grey tints very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.02-Allargentum-Dyscrasite series II/A.02-10 Allargentum II/A.02-20 Dyscrasite

Ag1-xSbx Ag3Sb

6/m 2/m 2/m mm2

Descriptions A Large dyscrasite (elongated and angular, slight cream tint) surrounded by native antimony (white) and native arsenic (light grey), irregular safflorite (darkest grey, still very light); St. Andreasberg, Hartz Mts., Germany [f]; Nic. // B Subhedral dyscrasite (cream-white, scratches) overgrown by safflorite (light grey); St. Andreasberg, Hartz Mts., Germany [f]; Nic. // C Dyscrasite (medium grey, many scratches), safflorite (brown and blue anisotropy); St. Andreasberg, Hartz Mts., Germany [f]; Nic. +

96

Dyscrasite A

60 μ

C

B

125 μ

125 μ

97

Maucherite (Placodine = industrial, Temiskamite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins pinkish grey 50.80 - 52.95 Bireflectance: weak, dark olive to brown to violet

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.04-Dienerite-Maucherite series II/A.04-10 Dienerite II/A.04-20 Orcelite II/A.04-30 Maucherite ,

Ni3As Ni5-xAs2 Ni11As8

– 43m 6mm 422

Descriptions A Fibrous to massive maucherite (pinkish grey, slight bireflectance) replaced by nickeline (light orange, bireflectance) at contact to pararammelsbergite (light grey); Zinkwand Mt., Schladming, Styria, Austria [j]; Nic. // B Anhedral maucherite (slightly orange tinted grey) in skutterudite aggregate (very light grey), pyrrhotite (unusual, almost olive grey colour), goethite (dark grey); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. // C Maucherite (slight blue and greenish anisotropy), skutterudite (isotropic), pyrrhotite (here dark), goethite (brown internal reflections); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. +

98

Maucherite A

60 μ

C

B

250 μ

250 μ

99

Arsenopalladinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alluvial placers and ultra-basic intrusions white with yellowish creamy tint 54.85 - 56.81 brownish greys

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.05-Atheneite-Genkinite series II/A.05-10 Atheneite II/A.05-20 Vincentite II/A.05-30 Stillwaterite II/A.05-40 Arsenopalladinite II/A.05-50 Isomertieite II/A.05-60 Mertieite-I II/A.05-70 Mertieite-II II/A.05-80 Stibiopalladinite II/A.05-90 Palladoarsenide II/A.05-100 Palladobismutharsenide II/A.05-102 Palladodymite II/A.05-105 Rhodarsenide II/A.05-110 Majakite II/A.05-112 Menshikovite II/A.05-115 Polkanovite II/A.05-120 Genkinite

(Pd,Hg)3As (Pd,Pt)3(As,Sb,Te) Pd8As3 Pd8(As,Sb)3 Pd11Sb2As2 Pd11(Sb,As)4 Pd8(Sb,As)3 Pd5Sb2 Pd2As Pd2(As,Bi)

6/m 2/m 2/m mono. – 3 1 – 4/m 3 2/m hex. 3m 6mm 2/m ortho.

(Pd,Rh)2As (Rh,Pd)2As PdNiAs Pd3Ni2As3 Rh12As7 (Pt,Pd)4Sb3

2/m 2/m 2/m ortho. hex. hex. 6/m 422

Descriptions A Anhedral arsenopalladinite (light grey) intimately intergrown with majakite and isomertieite (optically, both are hardly distinguishable from arsenopalladinite) next to native gold (light yellow), bornite (brown with violet tinge), silicates (dark grey); Norilsk, Urals, Russia [h]; Nic. // B Anhedral arsenopalladinite (brownish grey, slightly darker than bornite), majakite and isomertieite (both are slightly brighter than arsenopalladinite), native gold (light grey, many scratches), bornite (brownish grey), silicates (whitish internal reflections); Norilsk, Urals, Russia [h]; Nic. +

100

Arsenopalladinite A

10 μ

B

10 μ 101

Isomertieite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers creamish tint 52.71 isotropic

Bireflectance:


(Pd,Hg)3As (Pd,Pt)3(As,Sb,Te) Pd8As3 Pd8(As,Sb)3 Pd11Sb2As2 Pd11(Sb,As)4 Pd8(Sb,As)3 Pd5Sb2 Pd2As Pd2(As,Bi) (Pd,Rh)2As (Rh,Pd)2As PdNiAs Pd3Ni2As3 Rh12As7 (Pt,Pd)4Sb3

6/m 2/m 2/m mono. 3 1 – 4/m 3 2/m hex. 3m 6mm 2/m ortho. 2/m 2/m 2/m ortho. hex. hex. 6/m 422

Descriptions A Anhedral isomertieite (slight cream tint) intergrown with stibiopalladinite (upper portion of grain; white with slight bluish tint); Maandagshoek, South Africa [d]; Nic. // B Anhedral isomertieite (brownish grey) intergrown with gold (yellow); Choudnoe, Urals, GUS [d]; Nic. //

102

Isomertieite A

24 μ

B

13 μ 103

Stibiopalladinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt deposits white with slight yellowish to bluish tint 54.85 - 55.38 Bireflectance: distinct, colours usually lacking but some grains are purplish grey to greenish grey weak, yellowish to bluish



6/m 2/m 2/m mono. – 3 1 – 4/m 3 2/m hex. 3m 6mm 2/m ortho. 2/m 2/m 2/m ortho. hex. hex. 6/m 422

Descriptions A Subhedral stibiopalladinite (3 grains at upper portion of grain; white with slight bluish tint) intergrown with isomertieite (very slight cream tint); Maandagshoek, South Africa [d]; Nic. // B Stibiopalladinite (slightly lighter and darker anisotropy than isomertieite), isomertieite (brownish grey); Maandagshoek, South Africa [d]; Nic. +(+2°)

104

Stibiopalladinite A

24 μ

B

24 μ 105

Palladodymite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt placers from ultrabasic rocks brownish grey 56.50 - 48.30 Bireflectance: distinct, from bluish grey to reddish brown



6/m 2/m 2/m mono. – 3 1 – 4/m 3 2/m hex. 3m 6mm 2/m ortho. 2/m 2/m 2/m ortho. hex. hex. 6/m 422

Descriptions A Anhedral palladodymite (brownish grey, darkest mineral) and hongshiite (pinkish tint) as inclusions in rutheniridosmine (white with slight yellow tint); Miass, Urals, Russia [h]; Nic. //

106

Palladodymite A

3μ

107

Rhodarsenide Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

PGE placers light olive 49.50 - 48.20 Bireflectance: moderate to distinct weak



6/m 2/m 2/m mono. 3 1 – 4/m 3 2/m hex. 3m 6mm 2/m ortho. 2/m 2/m 2/m ortho. hex. hex. 6/m 422

Descriptions A Minute anhedral grain of rhodarsenide (light olive), intergrown with osmium (light grey) in laurite (medium grey) next to large grain of isoferroplatinum (light cream); Maandagshoek, South Africa [d]; Nic. // B Rhodarsenide (similar to isoferroplatinum; olive), osmium (darker brown), laurite (dark), isoferroplatinum (brownish grey); Maandagshoek, South Africa [d]; Nic. +

108

Rhodarsenide A

5μ

B

5μ 109

Telargpalite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

ultrabasic cumulates cream 52.02 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/A.07-Telargpalite-Borovskite series II/A.07-10 Telargpalite II/A.07-20 Keithconnite II/A.07-30 Telluropalladinite II/A.07-35 Oulankaite II/A.07-40 Sopcheite II/A.07-50 Temagamite II/A.07-60 Borovskite

(Pd,Ag)3Te Pd3-xTe Pd9Te4 (Pd,Pt)5(Cu,Fe)4SnTe2S2 Ag4Pd3Te4 Pd3HgTe3 Pd3SbTe4

cub. – 3 2/m tet. ortho. ortho. – 4/m 3 2/m

Descriptions A Telargpalite (cream, here very similar to oulankaite) intergrown with tulameenite (lightest grey) and oulankaite (light cream platelet, bireflectance not detectable here) in a matrix of chalcopyrite (yellow), silicates (dark grey); Lukkulaisvaara, N Karelia, Russia [h]; Nic. // B Telargpalite (brownish grey), tulameenite (dark), oulankaite (undulating cream to brown anisotropy), chalcopyrite (bluish grey), silicates (multicolour internal reflections); Lukkulaisvaara, N Karelia, Russia [h]; Nic. +

110

Telargpalite A

10 μ

B

10 μ 111

Oulankaite (Oulongaite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatoidal plagioclase-bearing pyroxenite light cream [45 - 52] Bireflectance: cream-grey to brown light to darker cream

weak




Descriptions A Euhedral oulankaite (darker cream, bireflectance compare picture B), telargpalite (cream, here lighter than oulankaite), tulameenite (lightest grey), chalcopyrite (yellow), silicates (dark grey); Lukkulaisvaara, N Karelia, Russia [h]; Nic. // B Oulankaite (light cream platelet, bireflectance) intergrown with telargpalite (cream, here very similar to oulankaite) and tulameenite (lightest grey) in a matrix of chalcopyrite (yellow), silicates (dark grey); Lukkulaisvaara, N Karelia, Russia [h]; Nic. // C Oulankaite (undulating cream to brown anisotropy), telargpalite (brownish grey), tulameenite (dark), chalcopyrite (bluish grey), silicates (multicolour internal reflections); Lukkulaisvaara, N Karelia, Russia [h]; Nic. +

112

Oulankaite A

9μ

C

B

12 μ

12 μ

113

Temagamite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal PGE-Au mineralisation hosted by gabbroic rocks and characterised by extensive carbonate-chlorite-sulfide alteration white with a grey tinge 54.20 - 55.00 Bireflectance: weak, pale to dark grey




Descriptions A Anhedral temagamite inclusion (slightly greyish white) in bornite (brown), chalcocite (blue), at least two unidentified minerals (greyish and yellow tint) in alteration rim around temagamite; Prince of Wales Island, Alaska, USA [h]; Nic. // B Temagamite (brown) in bornite (greyish brown), chalcocite (dark); Prince of Wales Island, Alaska, USA [h]; Nic. +

114

Temagamite A

6μ

B

6μ 115

Chalcocite (Cupreine, Redruthite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration products of Cu sulfide deposits blue-grey 29.93 Bireflectance: weak, often only visible with slightly opened analyser

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.01-Chalcocite-Yarrowite series II/B.01-10 Chalcocite II/B.01-20 Djurleite II/B.01-30 Digenite II/B.01-40 Roxbyite II/B.01-50 Anilite II/B.01-60 Geerite II/B.01-70 Spionkopite II/B.01-80 Yarrowite

A B C

D E

Cu2S Cu31S16 Cu9S5 Cu1.78S Cu7S4 Cu8S5 Cu1.4S Cu9S8

2/m 2/m – 3 2/m 2/m 2/m 2/m 2/m trig. 3m 3m

Descriptions Anhedral chalcocite (bluish-grey) replacing pyrite (light yellow) in colloform goethite (different darker grey shades), small covellite grains (blue); Thorn Trees mine, Namibia [c]; Nic. // Massive anhedral mass of chalcocite (bluish-grey), along grain boundaries replaced by goethite and fine-grained malachite (both dark grey); Thorn Trees mine, Namibia [c]; Nic. // With a slightly opened analyser chalcocite reveals its weak anisotropy (compare previous picture; violet to greenish dark); Thorn Trees mine, Namibia [c]; Nic. + (+2°) Subhedral chalcocite (blue-grey) replacing bornite (pinkish-brown) and being replaced by covellite (blue), chalcopyrite (yellow); Otjozonjati Mine, Namibia [c]; Nic. // Lamellar chalcocite (bluish grey) replacing bornite (brownish); Butte, Montana, USA [a]; Nic. //

116

Chalcocite A

120 μ

C

B

250 μ

250 μ

D

E

125 μ

66 μ 117

Djurleite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

secondary Cu sulfides in enrichment zones bluish grey 27.44 - 28.38 Bireflectance: weak, not always visible



2/m 2/m – 3 2/m 2/m 2/m 2/m 2/m trig. 3m 3m

Descriptions A Djurleite (bluish grey) is replaced by tenorite (brownish grey); Timna Mine, Eilat, Israel [j]; Nic. // B Djurleite (dark, anisotropy here not visible), tenorite (brown internal reflections); Timna Mine, Eilat, Israel [j]; Nic. +

118

Djurleite A

24 μ

B

24 μ 119

Digenite (Neodigenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu deposits, mafic intrusives, exhalations, pegmatites distinctly blue 19.89 mostly isotropic

Bireflectance:



2/m 2/m – 3 2/m 2/m 2/m 2/m 2/m trig. 3m 3m

Descriptions A Anhedral digenite (bluish grey) in native copper (pinkish); Broken Hill, Australia [c]; Nic. // B Digenite (blue) replacing tennantite (greenish grey, lightest mineral), surrounded by enargite (brownish tinted greys bireflectance); Khusib Springs mine, Namibia [d]; Nic. //

120

Digenite A

60 μ

B

24 μ 121

Anilite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

quartz vein (Ani mine, Japan) light blue-grey [15]

Bireflectance:



2/m 2/m – 3 2/m 2/m 2/m 2/m 2/m trig. 3m 3m

Descriptions A Replacement of anilite crystals (long laths) by covellite (blue pleochroism) and bornite (pinkish), dolomite (dark grey); Lower Silesia, Poland (Ramdohr’s description points to the dolomite quarry near Redziny, Czarnów) [j]; Nic. // B Euhedral anilite laths (slightly bluish, very similar to some chalcocites) replaced by covellite lamellae (various blue shades pleochroism) and bornite (pinkish), carbonate (dark grey); Lower Silesia, Poland (Ramdohr’s description points to the dolomite quarry near Redziny, Czarnów) [j]; Nic. // C Anilite (brownish grey), covellite (orange anisotropy), bornite (pinkish), carbonate (brownish grey); Lower Silesia, Poland (Ramdohr’s description points to the dolomite quarry near Redziny, Czarnów) [j]; Nic. +

122

Anilite A

7μ

C

B

50 μ

50 μ

123

Betekhtinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins in black cupriferous shales cream grey to yellowish cream 31.91 - 31.80 Bireflectance: strong, dark to medium brown to bluish

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.02-Betekhtinite-Bornite series II/B.02-10 Betekhtinite II/B.02-20 Gortdrumite II/B.02-30 Bornite

Cu10(Fe,Pb)S6 (Cu,Fe)6Hg2S5 Cu5FeS4

2/m 2/m 2/m ortho. 2/m 2/m 2/m

Descriptions A Irregular betekhtinite (brownish tint) intergrown with tennantite (greenish tint) and chalcocite (bluish tint), tungstenite (strong greyish bireflectance), bornite (pinkish brown); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. // B Anhedral betekhtinite (brownish tint) intergrown with chalcocite (bluish grey); Kombat mine, Namibia [d]; Nic. // C Betekhtinite (dark to medium brown to blue anisotropy), chalcocite (dark brown); Kombat mine, Namibia [d]; Nic. +

124

Betekhtinite A

40 μ

C

B

125 μ

125 μ

125

Bornite (Chalcomicline, Erubescite, Poikilite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

igneous intrusions, hydrothermal Cu ore veins, alteration product of Cu minerals pinkish brown 25.08 Bireflectance: weak to absent weak, not always noticeable

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.02-Betekhtinite-Bornite series II/B.02-10 Betekhtinite II/B.02-20 Gortdrumite II/B.02-30 Bornite

A B C D E

Cu10(Fe,Pb)S6 (Cu,Fe)6Hg2S5 Cu5FeS4

2/m 2/m 2/m ortho. 2/m 2/m 2/m

Descriptions Anhedral bornite (pinkish grey; Ag-rich) replacing pyrite (white), covellite (blue); Buena Esperanza mine, Chile [b]; Nic. // Anhedral bornite (pinkish-brown) replacing chalcopyrite (yellow); chalcocite (blue-grey) and covellite (blue) replace bornite; Otjozonjati Mine, Namibia [c]; Nic. // Bornite (pinkish-brown), chalcopyrite (yellow); chalcocite (blue-grey), covellite (blue) bornite; Otjozonjati Mine, Namibia [c]; Nic. + Anhedral bornite (pinkish grey; Ag-rich) with relict chalcopyrite lamellae (yellow), covellite (blue); Buena Esperanza mine, Chile [b]; Nic. // Massive bornite (pinkish grey) replacing individual laminae of colloform chalcopyrite (light yellow); unknown locality [a]; Nic. //

126

Bornite A

60 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 127

Berzelianite (Selenocupride) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veinlets in dolomite bluish grey 22.02 Bireflectance: isotropic, sometimes anisotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.03-Berzelianite-Athabascaite series II/B.03-10 Berzelianite II/B.03-20 Bellidoite II/B.03-30 Crookesite II/B.03-40 Sabatierite II/B.03-50 Umangite II/B.03-60 Athabascaite

Cu2Se Cu2Se Cu7(Tl,Ag)Se4 Cu4TlSe3 Cu3Se2 Cu5Se4

– 4/m 3 2/m 4/m – 4 4/m 2/m 2/m 222 ortho.

Descriptions A Massive berzelianite (bluish grey) with bornite lamellae (pinkish grey); Bukov, Czech Republic [a]; Nic. // B Anhedral berzelianite (bluish grey) in carbonate matrix (dark grey); Lasovice, Czech Republic [a]; Nic. // C Berzelianite (bluish grey), carbonate (bright internal reflections; some hematite with red internal reflections); Lasovice, Czech Republic [a]; Nic. +

128

Berzelianite A

12 μ

C

B

250 μ

250 μ

129

Crookesite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal bluish grey 31.79 - 36.69 Bireflectance: slight greenish, brownish, dark grey, violet weak but distinct, bluish tinge



– 4/m 3 2/m 4/m – 4 4/m 2/m 2/m 222 ortho.

Descriptions A Anhedral crookesite (medium grey with bluish tinge), clausthalite (white), chalcopyrite (yellow, very small); Lasovice, Czech Republic [a]; Nic. // B Crookesite (slight greenish, brownish, dark grey, and violet anisotropy), clausthalite (slightly lighter grey, scratched); Lasovice, Czech Republic [a]; Nic. +

130

Crookesite A

60 μ

B

60 μ 131

Umangite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins violet to greenish 14.18 - 16.05 Bireflectance: distinct very strong, dark to light orange shades violet to greenish



– 4/m 3 2/m 4/m – 4 4/m 2/m 2/m 222 ortho.

Descriptions A Anhedral umangite (distinct bireflectance, violet to greenish pleochroism; sub-parallel twinning); Santa Brigida mine, Sierra de Umango, Argentina [b]; Nic. // B Umangite (strong anisotropy with various orange shades; sub-parallel twinning); Santa Brigida mine, Sierra de Umango, Argentina [b]; Nic. +

132

Umangite A

44 μ

B

44 μ 133

Weissite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Cu mineralisation with minor Au in a hornblende rock bluish greys 31.05 - 32.83 Bireflectance: strong, blue to brownish grey distinct, bluish to grey

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.04-Weissite-Rickardite series II/B.04-10 Weissite II/B.04-20 Rickardite

A

B C D E

Cu1.9Te Cu7Te5

6/m 2/m 2/m ortho.

Descriptions Intergrowth of anhedral weissite (bluish to grey pleochroism, bireflectance) and weibullite (greenish grey pleochroism, distinctive bireflectance), quartz (dark grey); Falu mine, Falun, Dalarna, Sweden [j]; Nic. // Weissite (strong blue to brownish grey anisotropy), weibullite (medium grey to brownish anisotropy), quartz (milky internal reflections); Falu mine, Falun, Dalarna, Sweden [j]; Nic. + Anhedral weissite (bluish bireflectance) in gold (yellow, scratches), quartz (dark); Falu mine, Falun, Dalarna, Sweden [j]; Nic. // Massive weissite (blue-gray) intergrown with native gold (yellow) and rickardite (cream); North Kalgoorlie Mine, Kalgoorlie, Western Australia, Australia [j]; Nic. // Weissite (medium to dark brown anisotropy), native gold (greenish yellow, many scratches), rickardite (grey anisotropy); North Kalgoorlie Mine, Kalgoorlie, Western Australia, Australia [j]; Nic. +

134

Weissite A

40 μ

C

B

83 μ

32 μ

D

E

50 μ

50 μ 135

Rickardite (Sanfordite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late-stage low-temperature hydrothermal deposits cream-grey to blue to violet 23.04 - 19.03 Bireflectance: strong, orange-brown strong, blue to violet

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.04-Weissite-Rickardite series II/B.04-10 Weissite II/B.04-20 Rickardite

Cu1.9Te Cu7Te5

6/m 2/m 2/m ortho.

Descriptions A Intergrowth of rickardite (strong blue to violet pleochroism, weak bireflectance) and weissite (bluish grey pleochroism, bireflectance), native gold (yellow); North Kalgoorlie Mine, Kalgoorlie, Western Australia, Australia [j]; Nic. // B Rickardite (strong orange-brown anisotropy), weissite (dark brown to grey anisotropy), native gold (greenish, scratches); North Kalgoorlie Mine, Kalgoorlie, Western Australia, Australia [j]; Nic. +

136

Rickardite A

24 μ

B

24 μ 137

Argentite (Argyrite, Silver Glance) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low temperature hydrothermal veins dark grey [28] Bireflectance: isotropic, but occasionally slightly bluish grey to dark brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.05-Acantite-Empressite series II/B.05-02 Argentite II/B.05-10 Acanthite II/B.05-30 Naumannite II/B.05-35 Kurilite II/B.05-40 Hessite II/B.05-50 Aguilarite II/B.05-60 Cervelleite II/B.05-70 Benleonardite II/B.05-75 Tsnigriite II/B.05-80 Stützite II/B.05-90 Empressite

Ag2S Ag2S Ag2Se (Ag,Au)2(Te,Se,S) Ag2Te Ag4SeS Ag4TeS Ag8(Sb,As)Te2S3 Ag9SbTe3(S,Se)3 Ag5-xTe3 AgTe

– 4/m 3 2/m 2/m 222 cub. 2/m 222 cub. tet. mono. 6/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Reaction rim of argentite (greenish grey) between galena (light grey) and native silver (white); Monte Narba, Sardinia, Italy [b]; Nic. // B Subhedral argentite (medium grey, strongly scratched) next to stephanite (slightly brighter grey, few scratches); Freiberg, Saxony, Germany [e]; Nic. // C Argentite (twinned, bluish grey to dark brown anisotropy), stephanite (here dark); Freiberg, Saxony, Germany [e]; Nic. +

138

Argentite A

60 μ

C

B

250 μ

250 μ

139

Acanthite (Silver Glance) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low temperature hydrothermal sulfide veins, secondary enrichments grey 29.59 weak

Bireflectance:




Descriptions A Paramorphous acanthite replacing argentite (bluish grey) in nickeline matrix (mottled orange shades, bireflectance), rammelsbergite (white); Medenec (Kupferberg), Ústí Region, Czech Republic [a]; Nic. // B Irregular acanthite (medium grey) impregnations with inclusions of spherular iodargyrite (dark grey), Broken Hill, Australia [c]; Nic. // C Acanthite (dark), iodargyrite (light yellow internal reflections); Broken Hill, Australia [c]; Nic. +

140

Acanthite A

60 μ

C

B

125 μ

125 μ

141

Naumannite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

together with other selenides, quartz, and carbonates in hydrothermal veins bluish grey 33.53 - 36.02 Bireflectance: distinct but weak, bluish to brownish grey




Descriptions A Anhedral naumannite (bluish grey), chalcopyrite (creamish yellow), eskebornite (brownish shades, strong bireflectance), goethite (dark grey), silicates (dark grey); Tilkerode, Germany [a]; Nic. // B Naumannite (bluish to brownish grey anisotropy), chalcopyrite (dark olive grey), eskebornite (strong turquoise to dark brown anisotropy), goethite (reddish brown internal reflections), silicates (whitish internal reflections); Tilkerode, Germany [a]; Nic. +

142

Naumannite A

60 μ

B

60 μ 143

Hessite (Botesite, Savodinskite, Telluric Silver Glance) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate- to low-temperature hydrothermal veins grey with slight brownish tint 38.4 - 42.18 Bireflectance: distinct, brownish to bluish




Descriptions A Massive hessite (light grey, many scratches), chalcopyrite (yellow); Altai Mts., Western-Siberian Region, Russia [j]; Nic. // B Aggregate of euhedral hessite crystals (grey with slight brownish tint, scratches); Sawodinsk, Altai, Russia [e]; Nic. // C Hessite (brownish to bluish anisotropy); Sawodinsk, Altai, Russia [e]; Nic. +

144

Hessite A

120 μ

C

B

500 μ

500 μ

145

Jalpaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal medium grey 29.67 - 32.12 Bireflectance: distinct, medium to dark greys

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.06-Jalpaite-Imiterite series II/B.06-10 Jalpaite II/B.06-20 Mckinstryite II/B.06-30 Stromeyerite II/B.06-40 Eucairite II/B.06-50 Henryite II/B.06-55 Brodtkorbite II/B.06-60 Imiterite

Ag3CuS2 (Ag,Cu)2S AgCuS CuAgSe Cu4Ag3Te4 Cu2HgSe2 Ag2HgS2

4/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m cub. 2/m 2/m

Descriptions A Anhedral jalpaite (medium grey, slight bireflectance), partially replaced by covellite (blue shades, bireflectance); Smeinogorsk, Altai, Russia [e]; Nic. // B Jalpaite (medium and dark grey, strong anisotropy), covellite orange anisotropy); Smeinogorsk, Altai, Russia [e]; Nic. +

146

Jalpaite A

60 μ

B

60 μ 147

Stromeyerite (Cyprargyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Ag veins bluish and brownish grey 27.36 - 29.57 Bireflectance: distinct strong, vivid blue to deep violet and brown weak, bluish and brownish grey




Descriptions A Massive stromeyerite (bluish grey, bireflectance practically not visible here), tennantite (greenish grey) bornite (brownish), covellite (blue, here only slight bireflectance); Magma Mine, Superior, Arizona, USA [a]; Nic. // B Stromeyerite (strong blue to brown anisotropy), tennantite (isotropic), bornite (dark), covellite (orange anisotropy); Magma Mine, Superior, Arizona, USA [a]; Nic. +

148

Stromeyerite A

60 μ

B

60 μ 149

Eucairite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Se deposits cream-white 35.99 - 36.77 Bireflectance: strong, blue-grey to brown weak




Descriptions A Anhedral eucairite (cream-grey) between tyrrellite (light cream) and umangite (violet to greenish grey pleochroism, bireflectance); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. // B Anhedral eucairite (cream-white) next to klockmannite (greenish grey to blue, bireflectance) in matrix of umangite (greenish to violet); Santa Brigida mine, Sierra de Umango, Argentina [b]; Nic. // C Eucairite (blue-grey to brown), klockmannite (to grey to orange anisotropy), umangite (orange to brown anisotropy); Santa Brigida mine, Sierra de Umango, Argentina [b]; Nic. +

150

Eucairite A

10 μ

C

B

125 μ

125 μ

151

Fischesserite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

carbonate veins in epithermal precious metal deposits pinkish grey 31.10

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.07-Petrovskaite-Muthmannite series II/B.07-10 Petrovskaite II/B.07-20 Uytenbogaardtite II/B.07-30 Criddleite II/B.07-40 Penzhinite II/B.07-50 Fischesserite II/B.07-60 Petzite II/B.07-70 Muthmannite

AuAg(S,Se) Ag3AuS2 TlAg2Au3Sb10S10 (Ag,Cu)4Au(S,Se)4 Ag3AuSe2 Ag3AuTe2 AgAuTe2

mono. 422 2/m 622 432 432 ortho.

Descriptions A Anhedral fischesserite (pinkish grey, scratches), fine-grained klockmannite (bluish grey) altering clausthalite (light grey), quartz (dark grey); Predborice, Central Bohemia, Czech Republic [h]; Nic. // B Fischesserite (dark), klockmannite (mottled, dark), clausthalite (isotropic), quartz (white internal reflections); Predborice, Central Bohemia, Czech Republic [h]; Nic. +

152

Fischesserite A

60 μ

B

60 μ 153

Petzite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

vein-controlled Au-Te deposits bluish tinted grey 37.41 Bireflectance: sometimes noticeable

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.07-Petrovskaite-Muthmannite series II/B.07-10 Petrovskaite II/B.07-20 Uytenbogaardtite II/B.07-30 Criddleite II/B.07-40 Penzhinite II/B.07-50 Fischesserite II/B.07-60 Petzite II/B.07-70 Muthmannite

AuAg(S,Se) Ag3AuS2 TlAg2Au3Sb10S10 (Ag,Cu)4Au(S,Se)4 Ag3AuSe2 Ag3AuTe2 AgAuTe2

mono. 422 2/m 622 432 432 ortho.

Descriptions A Anhedral petzite (mottled bluish tinted grey) partially replaced by pyrite (cream-white) and tetradymite (?, lighter grey), quartz (dark grey); Gold Hill, Colorado, USA [a]; Nic. // B Anhedral petzite (bluish tinted grey) intergrown with sphalerite (darker grey), subhedral pyrite (cream-white), quartz (dark grey); Gold Hill, Colorado, USA [a]; Nic. // C Petzite (dark, no visible anisotropy), sphalerite (isotropic, some brown internal reflections), pyrite (isotropic), quartz (multicolour internal reflections); Gold Hill, Colorado, USA [a]; Nic. +

154

Petzite A

31 μ

C

B

61 μ

61 μ

155

Argyrodite (Brongniardite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal low-temperature polymetallic deposits with Ag sulfosalts and high-temperature Sn-Ag deposits grey with violet tint 24.80 weak, dark grey very weak

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.08-Argyrodite-Canfieldite series II/B.08-05 Putzite II/B.08-10 Argyrodite II/B.08-20 Canfieldite

A B C D E

(Cu4.7Ag3.3)GeS6 Ag8GeS6 Ag8SnS6

– 43m mm2 mm2

Descriptions Colloform argyrodite (medium grey) on marcasite (cream-white); Freiberg, Saxony, Germany [e]; Nic. // Anhedral argyrodite (medium grey) intergrown with marcasite (cream-white); Freiberg, Saxony, Germany [e]; Nic. // Argyrodite (dark grey anisotropy, hardly visible), marcasite (turquoise to blue to brownish grey anisotropy); Freiberg, Saxony, Germany [e]; Nic. + Massive argyrodite (twin lamellae with dark grey and greenish grey anisotropy, poorly visible); Freiberg, Saxony, Germany [e]; Nic. + (+2°) Colloform argyrodite (medium grey) grading into more massive argyrodite; Freiberg, Saxony, Germany [e]; Nic. //

156

Argyrodite A

239 μ

C

B

125 μ

125 μ

D

E

125 μ

500 μ 157

Canfieldite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal bluish to violet tinted grey 24.85 Bireflectance: difficult to discern

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.08-Argyrodite-Canfieldite series II/B.08-05 Putzite II/B.08-10 Argyrodite II/B.08-20 Canfieldite

A B

C

D

E

(Cu4.7Ag3.3)GeS6 Ag8GeS6 Ag8SnS6

– 43m mm2 mm2

Descriptions Botryoidal canfieldite (bluish grey), fine-grained galena (light grey); Colquechaca, Chayanta Province, Potosí Department, Bolivia [j]; Nic. // Euhedral mass of canfieldite (bluish tinted grey) intergrown with sphalerite (medium grey) and löllingite (slight yellow tint); Colquechaca, Chayanta Province, Potosí Department, Bolivia [j]; Nic. // Canfieldite (mottled dark brownish grey), sphalerite (brown internal reflections), löllingite (strong blue to brown anisotropy); Colquechaca, Chayanta Province, Potosí Department, Bolivia [j]; Nic. + Rhythmic intergrowth of canfieldite (light grey) and argyrodite (slightly darker), finest specs of native silver (white); Consuelo Mine, Colquechaca, Chayanta Province, Potosí Department, Bolivia [j]; Nic. // The same sample position as before (compare picture D), but 4 minutes later, showing strong light etching: both canfieldite (practically white) and argyrodite (light grey), finest native silver coats everything; Consuelo Mine, Colquechaca, Chayanta Province, Potosí Department, Bolivia [j]; Nic. //

158

Canfieldite A

120 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 159

Shandite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

serpentine light cream-grey [40] Bireflectance: strong, in grey-blue and yellow brown distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.12-Rhodplumsite-Oregonite series II/B.12-10 Rhodplumsite II/B.12-20 Shandite II/B.12-25 Laflammeite II/B.12-30 Parkerite II/B.12-40 Heazlewoodite II/B.12-50 Oregonite

Pb2Rh3S2 Pb2Ni3S2 Pd3Pb2S2 Ni3(Bi,Pb)2S2 Ni3S2 Ni2FeAs2

– 3 2/m – 3 2/m 2/m 2/m 2/m 2/m 32 hex.

Descriptions A Irregular shandite (light cream-grey) next to heazlewoodite (light yellowish cream, large grains), pyrite (light cream, cataclastic cracks), magnetite (medium grey), silicates (dark grey); Trial Harbour, Tasmania, Australia [g]; Nic. // B Shandite (blue anisotropy), heazlewoodite (brownish greys anisotropy), pyrite (isotropic), magnetite (isotropic), valleriite (fine rims, brown anisotropy), silicates (brownish to colourless internal reflections); Trial Harbour, Tasmania, Australia [g]; Nic. + C Shandite (same picture as before; brownish grey anisotropy), heazlewoodite (violet to brownish grey anisotropy), pyrite (isotropic), magnetite (isotropic), valleriite (fine rims, brown anisotropy), silicates (brownish to colourless internal reflections); Trial Harbour, Tasmania, Australia [g]; Nic. +

160

Shandite A

28 μ

C

B

125 μ

125 μ

161

Parkerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal sulfide and arsenide deposits grey shades 46.53 - 51.23 Bireflectance: greenish grey to grey-brown perceptible

slight



– 3 2/m – 3 2/m 2/m 2/m 2/m 2/m 32 hex.

Descriptions A Lamellar parkerite (medium grey shades, bireflectance), geversite (lighter grey), chalcopyrite (olive), native silver (white), cabriite (pinkish brown); Oktjabrsky, Norilsk, GUS [d]; Nic. // B Anhedral parkerite (medium grey shades, bireflectance, lamellar), geversite (lighter grey), chalcopyrite (olive), niggliite (cream), native silver (white), cabriite (pinkish brown, slight bireflectance); Oktjabrsky, Norilsk, GUS [d]; Nic. // C Parkerite (various grey shades, lamellar), geversite (dark), chalcopyrite (dark greenish grey), niggliite (bright cream to bluish anisotropy), native silver (medium grey), cabriite (red-brown to brown anisotropy); Oktjabrsky, Norilsk, GUS [d]; Nic. +

162

Parkerite A

24 μ

C

B

125 μ

125 μ

163

Heazlewoodite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

serpentine, probably hydrothermal cream-white 57.78 Bireflectance: strong to indistinct, brown to bluish grey



– 3 2/m – 3 2/m 2/m 2/m 2/m 2/m 32 hex.

Descriptions A Large anhedral heazlewoodite (light cream), pyrite (slightly darker cream, many cataclastic cracks), magnetite (medium grey), silicates (dark grey); Trial Harbour, Tasmania, Australia [g]; Nic. // B Heazlewoodite (patchy blue and dark anisotropy), pyrite (isotropic), magnetite (isotropic), silicates (colourless to brownish internal reflections); Trial Harbour, Tasmania, Australia [g]; Nic. + C Heazlewoodite (pink to olive anisotropy), millerite (strong blue to golden anisotropy), magnetite (isotropic), serpentine (greenish internal reflections); Heazlewood River, Tasmania, Australia [a]; Nic. + (+2°)

164

Heazlewoodite A

60 μ

C

B

125 μ

250 μ

165

Oregonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

serpentinite light grey with brownish tint 50.64 Bireflectance: weak, brownish to greenish grey very weak, greys

very weak



– 3 2/m – 3 2/m 2/m 2/m 2/m 2/m 32 hex.

Descriptions A Massive granular oregonite (light grey with brownish tint, very slight bireflectance and pleochroism to grey), silicates (almost black); Josephine Creek, Josephine Co., Oregon, USA [j]; Nic. // B Oregonite (dark brownish grey to greenish grey anisotropy), silicates (diffuse green internal reflections); Josephine Creek, Josephine Co., Oregon, USA [j]; Nic. +

166

Oregonite A

60 μ

B

60 μ 167

Hauchecornite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal pinkish 47.71 - 50.56

Bireflectance:

very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.15-Hauchecornite group II/B.15-10 Tucekite II/B.15-20 Hauchecornite II/B.15-30 Arsenohauchecornite II/B.15-40 Tellurohauchecornite II/B.15-50 Bismutohauchecornite

Ni9Sb2S8 Ni9Bi(Sb,Bi)S8 Ni18Bi3AsS16 Ni9BiTeS8 Ni9Bi2S8


Descriptions A Subhedral hauchecornite (pink tint) with millerite exsolution lamellae (yellow), siegenite (grey); Friedrich mine, Wissen, Germany [a]; Nic. // B Massive hauchecornite (pink tint, mainly left part of picture) intergrown with siegenite (grey) and millerite (yellow, subhedral aggregate); Friedrich mine, Wissen, Germany [a]; Nic. // C Hauchecornite (dark brownish grey), siegenite/linnaeite (darkest grey), millerite (olive shades anisotropy); Friedrich mine, Wissen, Germany [a]; Nic. +

168

Hauchecornite A

24 μ

C

B

125 μ

125 μ

169

Pentlandite (Folgerite, Lillhammerite, Nicopyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

basic and ultrabasic intrusive igneous rocks light cream 51.64 (48.55 rhodian) isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.16-Pentlandite group II/B.16-10 Pentlandite II/B.16-20 Cobaltpentlandite II/B.16-30 Argentopentlandite II/B.16-40 Geffroyite II/B.16-50 Manganeseshadlunite II/B.16-60 Shadlunite II/B.16-70 Palladseite II/B.16-80 Miassite

(Fe,Ni)9S8 Co9S8 Ag(Fe,Ni)8S8 (Ag,Cu,Fe)9(Se,S)8 (Mn,Pb)(Cu,Fe)8S8 (Pb,Cd)(Fe,Cu)8S8 Pd17Se15 Rh17S15

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Pentlandite “flames” (light cream) in pyrrhotite (brownish tinted grey), pyrite crystal (white), chalcopyrite (yellow), quartz (dark grey); Outokumpu Mine, Outokumpu, Finland [j]; Nic. // B Massive pentlandite (yellowish cream) with alteration products along cracks, pyrrhotite (slightly darker cream), chalcopyrite (yellow); Madziwa Ni mine, Zimbabwe [d]; Nic. // C Pentlandite (cream) with oriented chalcopyrite exsolution (yellow); Majak mine, Talnak, GUS [d]; Nic. //

170

Pentlandite A

40 μ

C

B

125 μ

110 μ

171

Miassite (Prassoite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers, inclusions in isoferroplatinum light grey 39.05 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.16-Pentlandite group II/B.16-10 Pentlandite II/B.16-20 Cobaltpentlandite II/B.16-30 Argentopentlandite II/B.16-40 Geffroyite II/B.16-50 Manganeseshadlunite II/B.16-60 Shadlunite II/B.16-70 Palladseite II/B.16-80 Miassite

(Fe,Ni)9S8 Co9S8 Ag(Fe,Ni)8S8 (Ag,Cu,Fe)9(Se,S)8 (Mn,Pb)(Cu,Fe)8S8 (Pb,Cd)(Fe,Cu)8S8 Pd17Se15 Rh17S15


Descriptions A Rounded grain of miassite (light grey, larger part of grain) intergrown with cuprorhodsite (slightly lighter); grain at upper right: Cooperite with rim of native platinum; Maandagshoek, South Africa [d]; Nic. // B Miassite and cuprorhodsite are practically indistinguishable (medium to dark grey), Cooperite (darker than miassite), native platinum (strongly scratched and lighter); Maandagshoek, South Africa [d]; Nic. +

172

Miassite A

16 μ

B

16 μ 173

Mackinawite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

serpentinised ultrabasic rocks lighter and darker cream shades 22.38 - 47.13 Bireflectance: extreme, brownish to blue strong, cream shades

distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.17-Mackinawite-Karaelakhite series II/B.17-10 Mackinawite II/B.17-20 Godlevskite II/B.17-30 Kharaelakhite

(Fe,Ni)S0.9 (Ni,Fe)9S8 (Pt,Cu,Pb,Fe,Ni)9S8

4/m 2/m 2/m 222 2/m 2/m 2/m

Descriptions A Lamellar mackinawite (brownish to cream, bireflectance) in massive chalcopyrite (yellow), chalcocite (blue) as alteration product along cracks; Mackinaw Mine (Weden Creek Mine), Monte Cristo, Snohomish Co., Washington, USA [a]; Nic. // B Mackinawite (cream to light blue anisotropy), chalcopyrite (dark bluish grey), chalcocite (almost black); Mackinaw Mine (Weden Creek Mine), Monte Cristo, Snohomish Co., Washington, USA [a]; Nic. +

174

Mackinawite A

24 μ

B

24 μ 175

Godlevskite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, peridotites olive tinted grey 52.81 - 53.14 Bireflectance: bluish to reddish, not always properly visible weak, pale cream to pinkish cream

Strunz Classification - Group Members - Chemical Formula - Crystallography II/B.17-Mackinawite-Karaelakhite series II/B.17-10 Mackinawite II/B.17-20 Godlevskite II/B.17-30 Kharaelakhite

(Fe,Ni)S0.9 (Ni,Fe)9S8 (Pt,Cu,Pb,Fe,Ni)9S8

4/m 2/m 2/m 222 2/m 2/m 2/m

Descriptions A Anhedral godlevskite (slightly olive tinted grey, pleochroism not observable here, irregular cracks) intergrown with native copper (pinkish red), silicates (dark grey shades); Totalpmassiv, Graubünden, Switzerland [i]; Nic. // B Godlevskite (dark grey, slight anisotropy), native copper (brownish grey, scratches, red reflections within silicates), silicates (white to grey internal reflections); Totalpmassiv, Graubünden, Switzerland [i]; Nic. +

176

Godlevskite A

24 μ

B

24 μ 177

Sphalerite (False Galena, Mock Lead Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


hydrothermal sulfide veins, submarine medium grey depending on composition: colourless, yellow, orange, red, brown, green 16.36 Bireflectance: (16.8 manganoan-ferroan) isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.01-Sphalerite group and related compounds II/C.01-10 Sphalerite (Zn,Fe)S II/C.01-20 Hawleyite CdS II/C.01-30 Metacinnabar HgS II/C.01-40 Stilleite ZnSe II/C.01-50 Tiemannite HgSe II/C.01-60 Coloradoite HgTe II/C.01-70 Polhemusite (Zn,Hg)S

A B C D

E

– 43m – 43m – 43m – 43m – 43m – 43m 4/m

Descriptions Massive sphalerite (medium grey) with chalcopyrite disease (DIS; yellow); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // Skeletal sphalerite (grey) in chalcopyrite (yellow); Outokumpu Mine, Outokumpu, Finland [j]; Nic. // Sphalerite (brown to whitish internal reflections show Fe concentrations), galena (dark); Wiesloch, Germany [b]; Nic. + Euhedral sphalerite (transparent, brown internal reflections), colloform amorphous silica (greyish internal reflections, round aggregates), anglesite (white internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Anhedral Sphalerite (bright green internal reflections); Tsumeb, Namibia [b]; Nic. +

178

Sphalerite A

40 μ

C

B

20 μ

500 μ

D

E

125 μ

125 μ 179

Metacinnabar (Onofrite, Saukovite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

near-surface low-temperature hydrothermal deposits brownish to faintly bluish grey practically no red internal reflections (cinnabar intergrowths?) [30] Bireflectance: isotropic, occasionally brownish grey to dark anisotropy weak, occasionally brownish to bluish grey


– 43m – 43m – 43m – 43m – 43m – 43m 4/m

Descriptions A Lamellar twinning of metacinnabar (grey to bluish grey pleochroism), pyrite (cream); Concepción Mine, Teloloapan, Guerrero, Mexico [j]; Nic. // B Lamellar metacinnabar (dark brownish to black anisotropy) is partially replaced by cinnabar (strong greenish anisotropy, red internal reflections); Concepción Mine, Teloloapan, Guerrero, Mexico [j]; Nic. +

180

Metacinnabar A

60 μ

B

120 μ 181

Stilleite (Zincselenide) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Ni-Co-sulfide veins medium grey [30] isotropic

Bireflectance:


– 43m – 43m – 43m – 43m – 43m – 43m 4/m

Descriptions A Euhedral stilleite (medium grey) in carbonate matrix (dark grey); Shinkolobwe Mine, Shinkolobwe, Katanga (Shaba), Zaire [j]; Nic. // B Intergrowth of stilleite (medium grey) and linnaeite (cream), small covellite grain (blue, bireflectance); Shinkolobwe Mine, Shinkolobwe, Katanga (Shaba), Zaire [j]; Nic. // C Stilleite (isotropic, darkest grey), linnaeite (isotropic, lighter grey), covellite (orange anisotropy); Shinkolobwe Mine, Shinkolobwe, Katanga (Shaba), Zaire [j]; Nic. +

182

Stilleite A

24 μ

C

B

125 μ

125 μ

183

Tiemannite (Selenmercury) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins bluish grey 28.87 isotropic

Bireflectance:


– 43m – 43m – 43m – 43m – 43m – 43m 4/m

Descriptions A Anhedral tiemannite (bluish grey) in carbonate matrix (dark grey, slight bireflectance), native gold (bright yellow); Eskaborner Berg, Tilkerode, Germany [g]; Nic. // B Anhedral tiemannite (bluish grey) intergrown with clausthalite (white), carbonate (dark grey); Eskaborner Berg, Tilkerode, Germany [g]; Nic. //

184

Tiemannite A

60 μ

B

60 μ 185

Coloradoite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

mesothermal hydrothermal light grey with brownish tint, tarnishing to dull purple 37.14 Bireflectance: isotropic, sometimes weak, dark brownish to bluish grey


– 43m – 43m – 43m – 43m – 43m – 43m 4/m

Descriptions A Anhedral coloradoite (medium grey), gold (yellow), tellurobismuthite (light greenish grey), chalcopyrite (olive, upper right); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. // B Anhedral coloradoite (light grey) intergrown with native tellurium (almost white), pyrite crystals (cream), quartz (dark grey); Kalgoorlie, Western Australia, Australia [j]; Nic. // C Coloradoite (very dark brown, practically no anisotropy visible) intergrown with native tellurium (almost white), pyrite crystals (cream), quartz (dark grey); Kalgoorlie, Western Australia, Australia [j]; Nic. +

186

Coloradoite A

60 μ

C

B

125 μ

125 μ

187

Lautite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins medium grey 30.25 - 31.15 Bireflectance: weak, blue to brown grey very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.02-Sphalerite group and related compounds II/C.02-10 Lautite CuAsS II/C.02-60 Dukeite Bi24Cr8O57(OH)6·3H2O

222 3m

Descriptions A Massive lautite (medium grey); Vater Abraham mine, Marienberg, Erzgebirge, Germany [a]; Nic. // B Lautite (blue to brown grey anisotropy); Vater Abraham mine, Marienberg, Erzgebirge, Germany [a]; Nic. + C Distinct twinning of lautite (bluish to brownish grey anisotropy); Vater Abraham mine, Marienberg, Erzgebirge, Germany [a]; Nic. + (+2°)

188

Lautite A

120 μ

C

B

250 μ

125 μ

189

Chalcopyrite (Torwanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal sulfides, disseminations in igneous rocks distinctive yellow, occasionally distinct greenish or brownish tints 38.69 - 39.80 Bireflectance: often weak, olive and blue

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.03-Chalcopyrite group and related compounds II/C.03-10 Chalcopyrite CuFeS2 II/C.03-20 Eskebornite CuFeSe2 II/C.03-25 Lenaite AgFeS2 II/C.03-30 Gallite CuGaS2 II/C.03-40 Roquesite CuInS2 II/C.03-50 Laforetite AgInS2

A

B C D E

– 42m – 42m – 42m – 42m – 42m – 42m

Descriptions Skeletal intergrowth of chalcopyrite (yellow) with sphalerite (medium grey), anglesite (medium grey but darker than sphalerite); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Massive chalcopyrite (yellow), magnetite (medium grey, partially as rim around chalcopyrite), carbonate matrix (dark grey); Palabora, South Africa [b]; Nic. // Chalcopyrite (olive brown and blue anisotropy in twins), magnetite (isotropic), carbonate (bright internal reflections); Palabora, South Africa [b]; Nic. + Massive Se-rich chalcopyrite (yellow), tiemannite (light grey), hematite platelets (medium grey), carbonate (dark grey); Eskaborner Berg, Tilkerode, Germany [g]; Nic. // Chalcopyrite disease (DIS; yellow), crystallographically controlled by sphalerite (medium grey); Ikuno Mine, Honshu, Japan [a]; Nic. //

190

Chalcopyrite A

60 μ

C

B

250 μ

250 μ

D

E

61 μ

25 μ 191

Eskebornite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal veins light brown, sometimes with orange tint 30.78 - 35.64 Bireflectance: visible blue to brownish, not always clearly visible cream-yellow to yellowish brown


A

B C D E

– 42m – 42m – 42m – 42m – 42m – 42m

Descriptions Myrmekitic eskebornite (brownish) replaced by clausthalite (light grey), Se-rich chalcopyrite (brownish yellow top left), hematite (medium grey, rounded grain, top), carbonate (dark grey); Tilkerode, Germany [g]; Nic. // Anhedral eskebornite (light brown), Se-rich chalcopyrite (brownish yellow), clausthalite (light grey), carbonate (dark grey); Tilkerode, Germany [g]; Nic. // Eskebornite (dark), chalcopyrite (dark), clausthalite (dark), carbonate (whitish and light brown internal reflections); Tilkerode, Germany [g]; Nic. + Massive eskebornite (brown pleochroism, bireflectance), tiemannite (bluish grey); Petrovice, Czech Republic [h]; Nic. // Eskebornite (blue to brownish anisotropy), tiemannite (dark); Petrovice, Czech Republic [h]; Nic. +

192

Eskebornite A

20 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 193

Lenaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

in goethite pseudomorphs after magnesian siderite in an Ag-Pb deposit brownish with violet tint [30]

Bireflectance:


– 42m – 42m – 42m – 42m – 42m – 42m

Descriptions A Eutectic intergrowth of lenaite (violet brown), stephanite (bluish grey), and freibergite (slight olive tint), goethite (dark grey); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. // B Lenaite (dark), stephanite (lighter and darker brown grey anisotropy), freibergite (black), goethite (dark brown, few brown internal reflections); Privolnoye deposit, Central Yakutia, Russia [h]; Nic. +

194

Lenaite A

8μ

B

8μ 195

Gallite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

base-metal veins with relatively high Ga content grey to blue-grey 18.65 low

Bireflectance:


– 42m – 42m – 42m – 42m – 42m – 42m

Descriptions A Lamellar intergrowth of gallite (grey) and chalcopyrite (yellow), renierite (violet-grey); Kipushi, Congo [d]; Nic. // B Lamellar gallite (medium grey) in sphalerite (darker grey), renierite (orange brown); Kipushi, Congo [d]; Nic. //

196

Gallite A

60 μ

B

60 μ 197

Roquesite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

with Cu sulfides in high-temperature hydrothermal Sn-W-Bi-Mo veins in highly metamorphosed rocks bluish grey 22.10 - 22.40 very weak

Bireflectance:


– 42m – 42m – 42m – 42m – 42m – 42m

Descriptions A Anhedral roquesite (bluish grey) in bornite (violet grey), covellite (blue), pyrite (white); Charrier, Allier, France [h]; Nic. // B Roquesite (dark, anisotropy not visible here), bornite (dark violet to greenish grey), covellite (orange anisotropy), pyrite (isotropic); Charrier, Allier, France [h]; Nic. +

198

Roquesite A

24 μ

B

60 μ 199

Isocubanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal cream 37.76 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.04-Chalcopyrite group, Mooihoekite-Orickite series II/C.04-10 Mooihoekite Cu9Fe9S16 II/C.04-20 Haycockite Cu4Fe5S8 II/C.04-30 Putoranite Cu1.1Fe1.2S2 II/C.04-35 Isochalcopyrite Cu8Fe9S16 II/C.04-40 Talnakhite Cu9(Fe,Ni)8S16 II/C.04-50 Isocubanite CuFe2S3 II/C.04-60 Orickite CuFeS2·H2O

– 42m 222 – 4/m 3 2/m cub. – 43m – 4/m 3 2/m hex.

Descriptions A Oriented isocubanite lamellae (cream) and mackinawite (darker cream, kinked lamellae in upper section) in chalcopyrite (yellow), pyrrhotite (cream), pyrite (cream tint); Ngezi Concession, Zimbabwe [d]; Nic. // B Exsolution of isocubanite (cream) in chalcopyrite (yellow), sphalerite (grey, brown internal reflection); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. //

200

Isocubanite A

24 μ

B

24 μ 201

Orickite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

mafic alkalic diatreme medium grey 42.80 Bireflectance: strong, from greyish brown to greyish blue weak, pale yellow to slightly deeper yellow

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.04-Chalcopyrite group, Mooihoekite-Orickite series II/C.04-10 Mooihoekite Cu9Fe9S16 II/C.04-20 Haycockite Cu4Fe5S8 II/C.04-30 Putoranite Cu1.1Fe1.2S2 II/C.04-35 Isochalcopyrite Cu8Fe9S16 II/C.04-40 Talnakhite Cu9(Fe,Ni)8S16 II/C.04-50 Isocubanite CuFe2S3 II/C.04-60 Orickite CuFeS2·H2O

– 42m 222 – 4/m 3 2/m cub. – 43m – 4/m 3 2/m hex.

Descriptions A Subhedral orickite (medium grey) in magnetite (brownish grey, partially altered); Coyote Peak, Humboldt Co., California, USA [h]; Nic. // B Orickite (bluish grey anisotropy, brown internal reflections), magnetite (isotropic); Coyote Peak, Humboldt Co., California, USA [h]; Nic. + C Orickite (dark brown anisotropy, brown internal reflections; compare previous picture - rotated ~ 45°), magnetite (isotropic); Coyote Peak, Humboldt Co., California, USA [h]; Nic. +

202

Orickite A

60 μ

C

B

125 μ

125 μ

203

Luzonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal deposits grey to pinkish grey 25.87 - 28.97 Bireflectance: weak strong, in greenish yellow and purplish weak, grey to pinkish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.06-Stannite group II/C.06-10 Luzonite II/C.06-20 Famatinite II/C.06-30 Permingeatite II/C.06-40 Briartite II/C.06-45 Barquillite II/C.06-50 Kuramite II/C.06-60 Stannite II/C.06-70 Ferrokesterite II/C.06-80 Kesterite II/C.06-90 Cernyite II/C.06-100 Velikite II/C.06-110 Hocartite II/C.06-120 Pirquitasite II/C.06-130 Sakuraiite II/C.06-140 Petrukite II/C.06-150 Rhodostannite II/C.06-160 Toyohaite

A

B C D E

Cu3AsS4 Cu3SbS4 Cu3SbSe4 Cu2(Zn,Fe)GeS4 Cu2CdGeS4 Cu3SnS4 Cu2FeSnS4 Cu2(Fe,Zn)SnS4 Cu2(Zn,Fe)SnS4 Cu2CdSnS4 Cu2HgSnS4 Ag2FeSnS4 Ag2ZnSnS4 (Cu,Zn,Fe,In,Sn)4S4 (Cu,Fe,Zn)2(Sn,In)S4 Cu2FeSn3S8 Ag2FeSn3S8

– 42m – 42m – 42m – 42m – 42m – 42m – 42m – 42m – 4 – 42m – 42m – 42m – 42m cub. mm2 4/m 4/m

Descriptions Aggregate of luzonite (slight pink tone) between enargite (left side, almost creamish brown against luzonite, small grains also enclosed by luzonite) and digenite (right, bluish), bornite (pinkish brown), galena (light grey), quartz (dark grey); Tsumeb, Otjikoto Region, Namibia [j]; Nic. // Massive luzonite (lamellar grey to pinkish grey pleochroism, bireflectance), pyrite (cream); Excelsior Mine, Cerro de Pasco, Peru [j]; Nic. // Luzonite (lamellar twins, brown to dark blue grey anisotropy), pyrite (slightly anisotropic); Excelsior Mine, Cerro de Pasco, Peru [j]; Nic. + Luzonite (lamellar twins, brown to dark blue grey anisotropy); Excelsior Mine, Cerro de Pasco, Peru [j]; Nic. + Luzonite (pinkish grey) replacing bornite (pinkish brown), digenite (bluish), and chalcopyrite (yellow), galena (light grey), quartz (dark grey); Tsumeb, Otjikoto Region, Namibia [j]; Nic. //

204

Luzonite A

31 μ

C

B

125 μ

125 μ

D

E

125 μ

66 μ 205

Famatinite (Antimony Enargite, Stibioluzonite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Ag-Pb deposit in Miocene dacite-andesite stratovolcanic complex pinkish brown to bluish grey 24.64 - 26.73 Bireflectance: strong, green, bluish, brown weak, bluish to pinkish grey

slight




Descriptions A Famatinite (bluish to pinkish grey pleochroism, bireflectance) is replaced by pyrite (light cream); Mexicana mine, Famatina, Argentina [g]; Nic. // B Massive famatinite (bluish to pinkish grey pleochroism, bireflectance), pyrite (light cream), quartz (dark grey); Mexicana mine, Famatina, Argentina [g]; Nic. // C Famatinite (green, bluish, brown anisotropy), pyrite (isotropic), small specs of covellite (bright orange anisotropy), quartz (white to multicolour internal reflections); Mexicana mine, Famatina, Argentina [g]; Nic. +

206

Famatinite A

60 μ

C

B

250 μ

250 μ

207

Permingeatite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal medium grey 24.78 - 25.55 Bireflectance: strong, violet and greenish grey




Descriptions A Anhedral permingeatite (medium grey) in galena (light grey), chalcocite (blue grey), chalcopyrite (yellow, in chalcocite), carbonate (dark grey); Predborice, Czech Republic [h]; Nic. // B Anhedral permingeatite (medium grey) in galena (light grey), chalcocite (blue grey); Predborice, Czech Republic [h]; Nic. // C Permingeatite (dark violet and greenish grey), galena (isotropic, many scratches), chalcocite (dark grey); Predborice, Czech Republic [h]; Nic. +

208

Permingeatite A

60 μ

C

B

50 μ

50 μ

209

Briartite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

inclusions in Ge-Ga-bearing sulfides grey to grey blue 27.02 weak

Bireflectance:



– 42m – 42m – 42m – 42m – 42m – 42m – 42m – 42m 4 – 42m – 42m – 42m – 42m cub. mm2 4/m 4/m

Descriptions A Irregular briartite inclusions (medium grey) in renierite (orange brown) next to tennantite (slightly brighter grey), small elongated chalcopyrite grains (yellow) and minute covellite (blue); Kipushi, Congo [d]; Nic. //

210

Briartite A

60 μ

211

Stannite (Cassiterolamprite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Sn veins medium grey with olive-green tint 28.69 - 29.45 Bireflectance: distinct, violet and slate-green indistinct


A B C D E



Descriptions Massive stannite (olive grey, typical cleavage), pyrite (cream), andorite (light grey); Itos Mine, Oruro, Bolivia [j]; Nic. // Lamellar intergrowth of stannite (greenish grey) and chalcopyrite (yellow); Talnakh, Norilsk, Urals, Russia [h]; Nic. // Stannite lamellae (greenish and violet anisotropy), chalcopyrite (dark olive and bluish anisotropy); Talnakh, Norilsk, Urals, Russia [h]; Nic. + Anhedral stannite (olive) in sphalerite (medium grey), galena (light grey), jamesonite (light grey needles), silicate matrix (dark); Kari Kari, Depto. Potosi, Bolivia [d]; Nic. // Eutectic intergrowth of stannite (tinted grey) and chalcopyrite (yellow), stannoidite (brownish grey); Shensei Gang, Ashio mine, Ashio, Honshu Island, Japan [j]; Nic. //

212

Stannite A

120 μ

C

B

125 μ

125 μ

D

E

125 μ

22 μ 213

Kesterite (Isostannite, Kösterite, Kusterite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal quartz-sulfide veinlets in Sn deposits olive tinted grey 23.20 - 24.15

Bireflectance:




Descriptions A Anhedral kesterite (olive tinted grey), small specs of chalcopyrite inclusions (yellow); Cligga Mine, Cornwall, Great Britain [a]; Nic. // B Kesterite (isotropic), chalcopyrite (bluish grey spots); Cligga Mine, Cornwall, Great Britain [a]; Nic. +

214

Kesterite A

15 μ

B

15 μ 215

Sakuraiite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

exsolution mineral in a banded hydrothermal sulfide vein olive-green-grey 22.50 almost isotropic

Bireflectance:




Descriptions A “Haze” of sakuraiite (olive-green-grey) exsolved in sphalerite, sphalerite without sakuraiite (medium grey), both types of sphalerite contain chalcopyrite disease, yellow), chalcopyrite also occurs separately (yellow); Ikuno Mine, Honshu, Japan [a]; Nic. // B Fine-grained “dusty” sakuraiite (olive-green-grey) exsolved in sphalerite (medium grey), chalcopyrite (yellow), arsenopyrite (white); Ikuno Mine, Honshu, Japan [a]; Nic. //

216

Sakuraiite A

24 μ

B

12 μ 217

Stannoidite (Hexastannine, Hexastannite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Sn deposits pinkish to brownish grey 26.44 - 28.04 Bireflectance: strong, dark orange-red to yellow-grey to turquoise to greenish distinct, light salmon-brown to brownish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.07-Stannite group, Stannoidite-Vinciennite series II/C.07-10 Stannoidite Cu8Fe3Sn2S12 II/C.07-20 Volfsonite Cu11Fe3Sn3S16

222 tet.

Descriptions A Reaction rim of stannoidite (orange to greenish grey pleochroism) around stannite (here grey impression), bornite as matrix (pink), chalcocite (blue), pyrite (cream); Shensei Gang, Ashio mine, Ashio, Honshu Island, Japan [j]; Nic. // B Stannoidite (strong orange and turquoise anisotropy), stannite (dark grey), bornite (dark brownish grey), chalcocite (dark), pyrite (isotropic); Shensei Gang, Ashio mine, Ashio, Honshu Island, Japan [j]; Nic. +

218

Stannoidite A

31 μ

B

31 μ 219

Mawsonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

massive to disseminated hydrothermal Cu ores in highly altered Cambrian volcanic rocks orange to cream tinted orange 26.77 - 26.34 Bireflectance: very strong, orange brown to turquoise strong, orange to cream tinted orange

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.08-Stannite group, Chatkalite-Mawsonite series II/C.08-10 Chatkalite Cu6FeSn2S8 II/C.08-20 Mawsonite Cu6Fe2SnS8

– 42m – 42m

Descriptions A Irregular intergrowth of mawsonite (orange to cream tinted orange pleochroism, compare following photo), stannoidite (slightly darker, more greyish tinted shades, bireflectance), and bornite (violet tinted brown, colour changed through minute exsolution/replacements), covellite (blue pleochroism); Avila, Salamanca, Spain [j]; Nic. // B Irregular intergrowth of mawsonite (orange to cream tinted orange pleochroism, compare previous photo), stannoidite (slightly darker, more greyish tinted shades, bireflectance), and bornite (violet tinted brown, colour changed through minute exsolution/replacements), covellite (blue pleochroism); Avila, Salamanca, Spain [j]; Nic. // C Mawsonite (orange brown to turquoise anisotropy), stannoidite (here grey to violet grey anisotropy), bornite (dark, many specs of lighter impregnations), covellite (bright orange anisotropy); Avila, Salamanca, Spain [j]; Nic. +

220

Mawsonite A

40 μ

C

B

83 μ

83 μ

221

Renierite (Orange Bornite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dolomite-hosted Cu-Pb-Zn deposits, hydrothermal polymetallic deposits brownish orange 28.68 - 30.32 Bireflectance: strong, olive to blue to violet

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.10-Stannite group, Germanite series II/C.10-10 Renierite II/C.10-15 Vinciennite II/C.10-20 Germanite II/C.10-30 Nekrasovite II/C.10-40 Colusite II/C.10-45 Stibiocolusite II/C.10-47 Germanocolusite II/C.10-50 Maikainite II/C.10-55 Ovamboite II/C.10-60 Sulvanite II/C.10-70 Polkovicite II/C.10-80 Morozeviczite

(Cu,Zn)11(Ge,As)2Fe4S16 Cu10Fe4Sn(As,Sb)S16 Cu26Fe4Ge4S32 Cu26V2(Sn,As,Sb)6S32 Cu12-13V(As,Sb,Sn,Ge)3S16 Cu13V(Sb,As,Sn)3S16 Cu13V(Ge,As)3S16 Cu20(Fe,Cu)6Mo2Ge6S32 Cu20(Fe,Cu,Zn)6W2Ge6S32 Cu3VS4 (Fe,Pb)3(Ge,Fe)1-xS4 (Pb,Fe)3Ge1-xS4

– 42m 422 – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Anhedral renierite (orange), galena (light grey), sphalerite (medium grey), chalcocite (bluish grey), pyrite (cream-white), small round inclusions of germanite (violet grey, small grains); Tsumeb, Namibia [d]; Nic. // B Renierite (orange-brown and violet-grey anisotropy), galena (isotropic, here medium grey), sphalerite (small internal reflections), chalcocite (slightly violet to greenish anisotropy), pyrite (isotropic, here greenish grey), germanite (dark grey); Tsumeb, Namibia [d]; Nic. + (+2°)

222

Renierite A

60 μ

B

60 μ 223

Germanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

primary Cu-Pb-Zn ores pinkish greys (W-rich: lighter) 22.16 isotropic

Bireflectance:



– 42m 422 – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Sub-hedral germanite (violet grey, lighter lamellae are W-rich), renierite (orange), sphalerite (medium grey), chalcocite (bluish grey), pyrite (cream-white); Tsumeb, Namibia [d]; Nic. // B Anhedral germanite (violet grey) intimately intergrown with renierite (orange), chalcocite (bluish grey), sphalerite (medium grey), galena (light grey); Tsumeb, Namibia [d]; Nic. //

224

Germanite A

60 μ

B

60 μ 225

Colusite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal copper veins cream to khaki 31.74 isotropic

Bireflectance:



– 42m 422 – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Ge-colusite (khaki) intergrown with tennantite (greenish grey) and pyrite (cream-white); Khusib Springs, Namibia [d]; Nic. // B Irregular Ge-colusite (khaki) exsolution (?) in tennantite (greenish grey) and sphalerite (medium grey); Khusib Springs, Namibia [d]; Nic. //

226

Colusite A

24 μ

B

16 μ 227

Sulvanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

V-containing hydrothermal Cu deposits light yellow 31.18 Bireflectance: isotropic, sometimes weakly anisotropic



– 42m 422 – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Large grain of sulvanite (light yellow) partially replaced by libethenite (medium grey) and malachite (darkest grey); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. // B Sulvanite (isotropic), libethenite (olive green internal reflections), malachite (green internal reflections); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. + C Anhedral sulvanite (unusual brownish tint), irregularly replaced by covellite (blue, bireflectance) and other unidentified minerals, quartz matrix (dark grey); Tsumeb, Otjikoto Region, Namibia [j]; Nic. //

228

Sulvanite A

60 μ

C

B

125 μ

44 μ

229

Tennantite (Binnite, Erythroconite, Fredericite, Julianite, Regnolite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


hydrothermal veins, contact metamorphic greenish grey 26.90 (28.5 zincian, 28.9 plumbian, 29.6 bismuthian, 30.4 mercurian) isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.11-Tetrahedrite group II/C.11-10 Tennantite II/C.11-20 Argentotennantite II/C.11-30 Giraudite II/C.11-40 Tetrahedrite II/C.11-50 Freibergite II/C.11-60 Goldfieldite II/C.11-70 Hakite II/C.11-75 Mgriite II/C.11-80 Chameanite

(Cu,Fe)12As4S13 (Ag,Cu)10(Zn,Fe)2(As,Sb)4S13 (Cu,Zn,Ag)12(As,Sb)4(Se,S)13 (Cu,Fe)12Sb4S13 (Ag,Cu,Fe)12(Sb,As)4S13 Cu12(Te,Sb,As)4S13 (Cu,Hg)3(Sb,As)(Se,S)3 Cu3AsSe3 (Cu,Fe)4As(Se,S)4

– 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 43m

Descriptions A Anhedral tennantite (greenish grey) between euhedral pyrite crystals (light yellow) and intergrown with enargite (pinkish grey); Kuisib Springs Mine E of Tsumeb, Namibia [c]; Nic. // B Irregular tennantite (greenish tint), tungstenite (strong bluish grey bireflectance), bornite (pinkish brown); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. //

230

Tennantite A

120 μ

B

60 μ 231

Tetrahedrite (Coppite, Fieldite, Nepalite, Stylopite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


hydrothermal veins, low- to moderate-temperature contact metamorphic medium grey with greenish tint faint, red 32.78 Bireflectance: (31.2 argentian, 31.9 zincian, 33.1 mercurian) isotropic


A B C

D E


– 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 43m

Descriptions Euhedral tetrahedrite (greenish tinted grey), enargite (violet grey), pyrite (cream); Recsk, Mátra Mts., Hungary [a]; Nic. // Skeletal tetrahedrite (light grey with greenish tint); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Anhedral annivite (Bi-tetrahedrite; bluish grey) with covellite (blue) and goethite (darker grey) on cracks, pyrite (cream) and chalcopyrite (yellow), quartz matrix (dark grey); Anniviertal, Wallis, Switzerland [d]; Nic. // Partially replaced annivite (Bi-tetrahedrite; grey with slight brownish tint), malachite and azurite (dark grey); Neubulach, Schwarzwald, Germany [d]; Nic. // Annivite (Bi-tetrahedrite; isotropic), malachite and azurite (green and blue internal reflections); Neubulach, Schwarzwald, Germany [d]; Nic. +

232

Tetrahedrite A

48 μ

C

B

125 μ

250 μ

D

E

250 μ

250 μ 233

Schwazite (Hermesite, Mercurian Tetrahedrite, Spaniolite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, low- to moderate-temperature contact metamorphic deposits medium greenish grey 32.00 isotropic

Bireflectance:



– 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 43m

Descriptions A Massive schwazite (medium greenish grey), galena (light grey), pyrite (cream), chalcopyrite (dull yellow), quartz (dark grey, euhedral); Kotterbach, Slovak Republic [d]; Nic. // B Anhedral schwazite (medium grey) covellite replacement (blue) on cracks, azurite (medium grey); Mina dell’Angina, Italy [d]; Nic. // C Schwazite (isotropic), covellite (orange anisotropy), azurite (blue internal reflections); Mina dell’Angina, Italy [d]; Nic. +

234

Schwazite A

60 μ

C

B

125 μ

125 μ

235

Freibergite (Aphtonite, Leukargyrite, Polytelite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal greenish to bluish grey 31.62 isotropic

Bireflectance:



– 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 43m

Descriptions A Massive freibergite (darkest greenish grey) intergrown with bournonite (lighter greenish grey), galena (light grey), sphalerite (medium grey, center, pyrite (cream): Bonanza mine, Saltio, Mexico [d]; Nic. // B Euhedral freibergite (bluish grey) intergrown with sphalerite (darker grey) and chalcopyrite (dull yellow), euhedral quartz (dark grey); Mouzaia, Algeria [d]; Nic. //

236

Freibergite A

60 μ

B

120 μ 237

Goldfieldite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

epithermal precious metal veins medium grey 30.25 isotropic

Bireflectance:



– 43m – 43m – 43m – 43m – 43m – 43m – 43m – 4/m 3 2/m – 43m

Descriptions A Massive goldfieldite (medium grey) intergrown with native gold (yellow) and bismuthinite (bluish grey), quartz (dark); Mohawk Mine, Goldfield District, Esmeralda Co., Nevada, USA [j]; Nic. // B Massive goldfieldite (medium grey) intergrown with native tellurium (cream-white) and bismuthinite needles (bluish grey); Mohawk Mine, Goldfield District, Esmeralda Co., Nevada, USA [j]; Nic. //

238

Goldfieldite A

24 μ

B

24 μ 239

Wurtzite (Radial Blende) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, submarine hydrothermal medium grey yellow to dark brown 16.26 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.13-Wurtzite series II/C.13-10 Wurtzite II/C.13-20 Matraite II/C.13-30 Greenockite II/C.13-40 Cadmoselite II/C.13-50 Rambergite

(Zn,Fe)S ZnS CdS CdSe MnS

6mm 3m 6mm 6mm 6mm

Descriptions A Euhedral wurtzite (medium grey), chalcopyrite yellow), marcasite (white); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // B Wurtzite crystal (bright brown internal reflections) in laminar sphalerite (brown internal reflections, very similar to wurtzite), gratonite (dark grey), jordanite (brownish to bluish anisotropy); Wiesloch, Baden, Germany [g]; Nic. +

240

Wurtzite A

120 μ

B

60 μ 241

Greenockite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins greenish grey very light lemon yellow to red-brown and blood red 18.61 Bireflectance: weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.13-Wurtzite series II/C.13-10 Wurtzite II/C.13-20 Matraite II/C.13-30 Greenockite II/C.13-40 Cadmoselite II/C.13-50 Rambergite

A B C D E

(Zn,Fe)S ZnS CdS CdSe MnS

6mm 3m 6mm 6mm 6mm

Descriptions Subhedral greenockite (greenish grey) in galena (light grey) replacing wood (dark, also relic patches in galena); Huscon mine, Arizona, USA [f]; Nic. // Greenockite (greenish grey, small internal reflections visible) in wood (dark), some pyrite (cream); Huscon mine, Arizona, USA [f]; Nic. // Greenockite (bright internal reflections), wood (dark), pyrite (dark); Huscon mine, Arizona, USA [f]; Nic. + Greenockite (greenish grey, small internal reflections visible) next to pyritised wood (cream), carbonate (dark); Huscon mine, Arizona, USA [f]; Nic. // Greenockite (orange red internal reflections), pyrite (dark), carbonate (bright internal reflections); Huscon mine, Arizona, USA [f]; Nic. +

242

Greenockite A

120 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 243

Enargite (Garbyite, Guayacanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate- to low-temperature hydrothermal veins pinkish grey to light pinkish brown rare, deep red 25.48 - 26.78 Bireflectance: slight strong, dark blue to brown weak, violet to bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.14-Cubanite series II/C.14-10 Enargite II/C.14-15 Stibioenargite II/C.14-20 Cubanite II/C.14-30 Sternbergite II/C.14-40 Argentopyrite

Cu3AsS4 Cu3(Sb,As)S4 CuFe2S3 AgFe2S3 AgFe2S3

mm2 ortho. 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Anhedral enargite (pinkish grey; bireflectance) intergrown with tennantite (greenish) and pyrite (light yellow); Kuisib Springs mine E of Tsumeb, Namibia [c]; Nic. // B Massive enargite (violet to bluish grey pleochroism), pyrite (cream), quartz (dark grey); Recsk, Mátra Mts., Hungary [a]; Nic. // C Enargite (lamellar blue to brown anisotropy), pyrite (isotropic), quartz (milky to multicolour internal reflections); Recsk, Mátra Mts., Hungary [a]; Nic. +

244

Enargite A

120 μ

C

B

192 μ

192 μ

245

Cubanite (Chalcopyrrhotite, Chalmersite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins cream 38.62 - 42.18 Bireflectance: distinctive, light blue and dark

slight, cream shades


A B C D

E



Descriptions Cubanite lamellae (cream shades, bireflectance) in chalcopyrite (yellowish olive); Strathcona mine, Sudbury, Canada [d]; Nic. // Cubanite (light blue and dark anisotropy), chalcopyrite (dark olive); Strathcona mine, Sudbury, Canada [d]; Nic. + Cubanite (light blue and violet brown anisotropy), chalcopyrite (blue and olive anisotropy); Strathcona mine, Sudbury, Canada [d]; Nic. + (+2°) Massive cubanite (cream, lower section, slight bireflectance) intergrown with massive chalcopyrite (yellow), covellite (blue), goethite (dark bluish grey); Mackinaw Mine (Weden Creek Mine), Monte Cristo, Snohomish Co., Washington, USA [a]; Nic. // Cubanite (darker to lighter grey anisotropy), chalcopyrite (patchy olive to bluish grey anisotropy), covellite (orange anisotropy), goethite (brown internal reflections); Mackinaw Mine (Weden Creek Mine), Monte Cristo, Snohomish Co., Washington, USA [a]; Nic. +

246

Cubanite A

120 μ

C

B

250 μ

250 μ

D

E

125 μ

125 μ 247

Sternbergite (Argyro-Pyrrhotite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

secondary mineral in Ag-bearing deposits light brown 33.67 - 37.99 Bireflectance: distinct strong, bluish to lilac, reddish brown to light green brown shades




Descriptions A Coarse aggregate of sternbergite (light brown, distinctive bireflectance), pyrargyrite (bluish grey); Jáchymov, Erzgebirge, Karlovy Vary, Bohemia, Czech Republic [j]; Nic. // B Sternbergite (strong lamellar bluish and brownish grey anisotropy), pyrargyrite (bright red internal reflections); Jáchymov, Erzgebirge, Karlovy Vary, Bohemia, Czech Republic [j]; Nic. + C Sternbergite (strong undulating bluish and brownish grey anisotropy); Vater Abraham Mine, Morgengang, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. +

248

Sternbergite A

60 μ

C

B

125 μ

167 μ

249

Argentopyrite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins white, bright grey 28.27 - 36.07 Bireflectance: relatively strong, deep blue to pale blue-grey




Descriptions A Argentopyrite (cream), small inclusions of marcasite (white); Marienberg, Saxony, Germany [j]; Nic. // B Fine-grained argentopyrite (cream) as vug coating in arsenic (light grey), goethite (darker grey); Marienberg, Saxony, Germany [j]; Nic. // C Argentopyrite (bluish to brownish grey anisotropy), arsenic (slightly more bluish grey), goethite (brown internal reflections); Marienberg, Saxony, Germany [j]; Nic. +

250

Argentopyrite A

60 μ

C

B

125 μ

125 μ

251

Niningerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

slightly metamorphosed enstatite chondrite meteorites white [65] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.15-Galenite group II/C.15-05 Keilite II/C.15-10 Niningerite II/C.15-20 Oldhamite II/C.15-30 Alabandite II/C.15-40 Galena II/C.15-50 Clausthalite II/C.15-60 Altaite II/C.15-70 Crerarite

(Fe,Mg)S (Mg,Fe,Mn)S (Ca,Mg,Fe)S MnS PbS PbSe PbTe (Pt,Pb)Bi3(S,Se)4-x


Descriptions A Subhedral niningerite (white), troilite (brownish tint), silicates (dark); Indarch Enstatite Chondrite EH4, Shusha Elisavetpol, Azerbaidzhan [h]; Nic. // B Niningerite (grey, isotropic), troilite (brownish anisotropy), silicates (various internal reflections); Indarch Enstatite Chondrite EH4, Shusha Elisavetpol, Azerbaidzhan [h]; Nic. +

252

Niningerite A

24 μ

B

24 μ 253

Oldhamite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

enstatite chondrite and achondrite meteorites, supergene U deposit brownish grey white to brownish [15] Bireflectance: isotropic




Descriptions A Granular oldhamite (brownish grey); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. // B Oldhamite (white to brownish internal reflections); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. +

254

Oldhamite A

24 μ

B

24 μ 255

Alabandite (Manganblende, Blumbachite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

epithermal sulfide veins grey with greenish tint bright green, brown (oxidation) 21.91 Bireflectance: isotropic


A B C D E



Descriptions Anhedral alabandite (medium grey) replaced by pyrolusite (cream); Nagyag, Rumania [e]; Nic. // Euhedral alabandite in matrix lamellae of larger alabandite crystals (light grey); Broken Hill, Australia [a]; Nic. // Alabandite (crystal and lamellae; green internal reflections); Broken Hill, Australia [a]; Nic. + Alabandite (crystal and lamellae; green internal reflections; core mixture brighter green); Broken Hill, Australia [a]; Nic. + Oriented exsolution of pyrrhotite (cream tint) in alabandite (medium grey), some pyrite (white); Hata Mine, Iwate, Japan [l]; Nic. //

256

Alabandite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 257

Galena (Boleslavite, Lead Glanc) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Pb sulfide veins, disseminations in igneous and sedimentary rocks white 41.56 Bireflectance: isotropic, non-stoichiometric specimens are slightly anisotropic


A B C D E



Descriptions Massive galena (light grey) with deformation lamellae (“Bleischweif”), chalcopyrite (yellow, at center); Neudorf, Hartz Mts., Germany [a]; Nic. // Anisotropic galena (light grey) in sphalerite (medium grey); Mt. Jourdanne, Southwest Indian Ridge [c]; Nic. // Anisotropic galena (various tinted greys), sphalerite (brown internal reflections); Mt. Jourdanne, Southwest Indian Ridge [c]; Nic. // Skeletal galena (light grey) in tennantite (greenish grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Galena (light grey) replacing anglesite (dark grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. //

258

Galena A

120 μ

C

B

125 μ

125 μ

D

E

250 μ

25 μ 259

Clausthalite (Lerbachite, Tilkerodite, Zorgite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-sulfur hydrothermal deposits together with other selenides light grey 48.84 isotropic

Bireflectance:




Descriptions A Irregular clausthalite (white) intergrown with chalcopyrite (brownish yellow) in silicate matrix (dark); Copper Cliff, Sudbury, Canada [d]; Nic. // B Massive clausthalite (light grey, scratched) between quartz (darker grey); Lasovice, Czech Republic [a]; Nic. //

260

Clausthalite A

60 μ

B

120 μ 261

Altaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Au vein deposits light grey with greenish tint 66.83 isotropic

Bireflectance:


A

B

C D E



Descriptions Irregular, partially oriented inclusions of altaite (light grey with greenish tint) and froodite (light grey with brownish tint) in sobolevskite (pinkish tint), djerfisherite (medium grey with brown tint), taimyrite (light brownish grey, thin rim on left side of sobolevskite), native silver (white), chalcopyrite (brownish olive), galena (medium grey); Oktjabrsky, Norilsk, Russia [h]; Nic. // Anhedral altaite (grey with greenish tint) around sobolevskite (slightly pinkish), chalcopyrite (olive), galena (medium grey, cleavage breakouts), magnetite matrix (dark grey); Oktjabrsky, Norilsk, Russia [d]; Nic. // Altaite (dark greenish grey), sobolevskite (pinkish grey), chalcopyrite (dark olive), galena (isotropic), magnetite (isotropic); Oktjabrsky, Norilsk, Russia [d]; Nic. + Massive altaite (light grey with greenish tint), small magnetite grains (medium grey), silicates (dark grey); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. // Altaite (isotropic, many scratches), magnetite (isotropic), silicates (green to white internal reflections); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. +

262

Altaite A

24 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 263

Miargyrite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Ag-bearing low-temperature hydrothermal sulfides greenish grey shades raspberry-red in fine grains 31.74 - 35.05 Bireflectance: weak strong, greenish greys distinct, in whites, light grey-whites, and whitish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.16-Miargyrite-Volynskite series II/C.16-05 Cuboargyrite II/C.16-10 Miargyrite II/C.16-15 Baumstarkite II/C.16-20 Aramayoite II/C.16-30 Matildite II/C.16-35 Schapbachite II/C.16-40 Bohdanowiczite II/C.16-50 Volynskite

A

B C

D E

AgSbS AgSbS2 Ag3(Sb,As)2SbS6 Ag3Sb2(Sb,Bi)S6 AgBiS2 AgBiS2 AgBiSe2 AgBiTe2

– 4/m 3 2/m 2/m – 1 – 1 – 3 2/m – 4/m 3 2/m – 3 2/m – 3 2/m

Descriptions Intergrowth of miargyrite (greenish grey), sphalerite (medium grey), galena (light grey), and fine native silver aggregates (white), chalcopyrite (yellow); Brand-Erbisdorf, Saxony, Germany [g]; Nic. // Miargyrite (pronounced greenish greys anisotropy, red internal reflections), galena (isotropic), chalcopyrite (dark); Brand-Erbisdorf, Saxony, Germany [g]; Nic. + Miargyrite (grey with blue tint; circular light etching occurred after a few minutes of exposure under a higher magnification objective), intergrown with polybasite laths (brownish tint) and chalcopyrite (yellow), carbonate (dark grey); Brand-Erbisdorf, Saxony, Germany [g]; Nic. // Massive miargyrite (bluish grey pleochroism, lower section), pyrargyrite (blues grey, upper section), safflorite (cream); Dolores I Mine, Chañarcillo, Copiapó Province, Chile [a]; Nic. // Miargyrite (strong bluish to brownish anisotropy, few red internal reflections), pyrargyrite (strong red internal reflections), safflorite (strong blue to brown anisotropy); Dolores I Mine, Chañarcillo, Copiapó Province, Chile [a]; Nic. +

264

Miargyrite A

60 μ

C

B

125 μ

153 μ

D

E

250 μ

250 μ 265

Aramayoite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Sn - Ag veins light grey minute red reflections 37.06 - 40.10 Bireflectance: dark blue to dark brown

faint



– 4/m 3 2/m 2/m – 1 – 1 – 3 2/m – 4/m 3 2/m – 3 2/m – 3 2/m

Descriptions A Aramayoite (minute red internal reflection); Animas Mine, Atocha District, Potosi Department, Bolivia [j]; Nic. + B Massive aramayoite (light grey, galena-like, faint bireflectance), stannite (olive grey), pyrite (cream); Animas Mine, Atocha District, Potosi Department, Bolivia [j]; Nic. // C Aramayoite (distinct but dark anisotropy from blue to brown), stannite (greenish greys anisotropy), pyrite (isotropic); Animas Mine, Atocha District, Potosi Department, Bolivia [j]; Nic. +

266

Aramayoite A

16 μ

C

B

250 μ

250 μ

267

Matildite (Argentobismutite, Morocochite, Peruvite, Schapbachite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate- to high-temperature hydrothermal deposits, pegmatites light grey 41.98 - 47.12 Bireflectance: very dark, anisotropy hardly visible weak



– 4/m 3 2/m 2/m – 1 – 1 – 3 2/m – 4/m 3 2/m – 3 2/m – 3 2/m

Descriptions A Anhedral matildite (grey with cream tint, center) in galena (grey); Ivigtut, Greenland [g]; Nic. / / B Matildite (slightly darker than galena, slight anisotropy), galena (dark grey); Ivigtut, Greenland [g]; Nic. + C Matildite (brown grey anisotropy), barite (dark and multicolour internal reflections); Cuadro Juan, Cosuno, Bolivia [d]; Nic. + (+2°)

268

Matildite A

60 μ

C

B

125 μ

71 μ

269

Herzenbergite (Kolbeckine) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, after cassiterite light grey dark red-brown 41.09 - 47.15 Bireflectance: dark blue and brown very low, light to darker blue-grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.17-Herzenbergite-Cylindrite series II/C.17-10 Herzenbergite II/C.17-20 Stistaite II/C.17-30 Mohite II/C.17-40 Teallite II/C.17-45 Suredaite II/C.17-50 Potosiite II/C.17-55 Levyclaudite II/C.17-60 Incaite II/C.17-70 Franckeite II/C.17-80 Cylindrite

SnS SnSb Cu2SnS3 PbSnS2 PbSnS3 Pb6Sn2FeSb2S14 Pb8Sn7Cu3(Bi,Sb)3S28 Pb4Sn4FeSb2S15 (Pb,Sn)6FeSn2Sb2S14 Pb3Sn4FeSb2S14

2/m 2/m 2/m – 3 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m – 1 2 – 1 – 1 – 1

Descriptions A Euhedral spindles of herzenbergite (light grey) replacing cassiterite (medium greys, slight bireflectance), quartz (dark grey); Maria Theresia mine, Huari, Bolivia [g]; Nic. // B Herzenbergite (dark blue and brown anisotropy), cassiterite (brown and brilliant internal reflections), quartz (white and multicolour internal reflections); Maria Theresia mine, Huari, Bolivia [g]; Nic. +

270

Herzenbergite A

60 μ

B

60 μ 271

Stistaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers creamy white 81.39 Bireflectance: slightly mottled brown shades



Descriptions A Rounded grain of stistaite (white, brittle cracks); NW Kirgisia [h]; Nic. // B Stistaite (slightly mottled brown shades anisotropy); NW Kirgisia [h]; Nic. +

272

2/m 2/m 2/m – 3 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m – 1 2 – 1 – 1 – 1

Stistaite A

60 μ

B

60 μ 273

Teallite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Sn veins white with a slight yellow tint 42.48 - 45.73 Bireflectance: strong, lighter to dark brown weak, in white with light golden tint to pure white



2/m 2/m 2/m – 3 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m – 1 2 – 1 – 1 – 1

Descriptions A Laths of teallite (almost white) in matrix of franckeite (light grey); Poópo, Bolivia [e]; Nic. // B Teallite (strong light to dark brown anisotropy), franckeite (very dark, bluish to brownish anisotropy); Poópo, Bolivia [e]; Nic. +

274

Teallite A

120 μ

B

120 μ 275

Franckeite (Lepidolamprite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

epithermal low-sulfidation Ag-Sn deposits (porphyry style) medium to light grey 35.08 - 37.08 Bireflectance: weak, brownish grey shades


A B C D E


2/m 2/m 2/m – 3 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m – 1 2 – 1 – 1 – 1

Descriptions Fibrous lamination of franckeite (light grey) around cylindrite (light grey, massive center) next to sphalerite (medium grey); Santa Cruz Poópo, Bolivia [b]; Nic. // Bent plate of franckeite (light grey) intergrown with large grains of cylindrite (light to mottled grey); Santa Cruz Poópo, Bolivia [b]; Nic. // Franckeite (twinning, more pronounced anisotropy similar to cylindrite), cylindrite (brown to blue); Santa Cruz Poópo, Bolivia [b]; Nic. + Franckeite (light grey) partially replaced by anglesite (medium grey); Santa Cruz Poópo, Bolivia [e]; Nic. // Franckeite crystal (light grey) with “feathering” termination; Santa Cruz Poópo, Bolivia [e]; Nic. //

276

Franckeite A

60 μ

C

B

250 μ

250 μ

D

E

125 μ

125 μ 277

Cylindrite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Sn veins medium grey 30.82 - 35.22 Bireflectance: brown to blue-grey very weak



Descriptions A Cross-sections of cylindrite (light grey); Santa Cruz Poopo, Bolivia [b]; Nic. // B Cylindrite (brown to blue anisotropy); Santa Cruz Poopo, Bolivia [b]; Nic. +

278

2/m 2/m 2/m – 3 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m – 1 2 – 1 – 1 – 1

Cylindrite A

239 μ

B

239 μ 279

Cinnabar (Cinnabarite, Cinabre, Zinnober) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:

low temperature hydrothermal medium grey strong red 27.61 - 28.41 Bireflectance:


strong, greenish grey

visible, especially at grain boundaries

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.18-Cinnabar-Hypercinnabar series II/C.18-10 Cinnabar II/C.18-20 Hypercinnabar

A

B C D E

HgS HgS

32 hex.

Descriptions Anhedral cinnabar (medium grey, bireflectance visible at triple junction in lower center) next to stibnite (lighter grey shades, bireflectance), 2 small euhedral arsenopyrites (white, center); Sizma mine, Konya, Turkey [b]; Nic. // Anhedral cinnabar (medium grey, bireflectance visible at triple junction at center) next to stibnite (lighter grey shades, bireflectance); Sizma mine, Konya, Turkey [b]; Nic. // Anhedral cinnabar (bright red internal reflections, anisotropy), stibnite (bluish to brownish anisotropy); Sizma mine, Konya, Turkey [b]; Nic. + Euhedral cinnabar (bluish grey) and colloform pyrite (cream) in matrix of amorphous silica (dark grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Microbial cinnabar filament (red internal reflections), realgar (orange), amorphous silica matrix (light internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

280

Cinnabar A

60 μ

C

B

125 μ

125 μ

D

E

25 μ

25 μ 281

Troilite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

serpentinites, layered ultramafic intrusives, basalts, meteorites light brown, similar to pyrrhotite [40] Bireflectance: strong, brownish and bluish grey light brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.19-Troilite-Pyrrhotite-Haideite series II/C.19-10 Troilite II/C.19-20 Pyrrhotite II/C.19-25 Jaipurite II/C.19-30 Westerveldite II/C.19-40 Modderite II/C.19-50 Smythite II/C.19-60 Achavalite II/C.19-70 Heideite

FeS Fe1-xS CoS (Fe,Ni,Co)As (Co,Fe)As (Fe,Ni)9S11 or (Fe,Ni)13S16 FeSe (Fe,Cr)1+x(Ti,Fe)2S4

6/m 2/m 2/m 2/m 6/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 3 2/m 6/m 2/m 2/m 2/m

Descriptions A Anhedral troilite (light brown pleochroism), ilmenite platelets (brownish grey pleochroism), goethite (bluish grey) as alteration product of troilite, silicates (dark grey); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. // B Troilite (brownish anisotropy), ilmenite (dark brownish to bluish grey anisotropy, here darkest mineral), goethite (brown internal reflections), silicates (multicolour and brown internal reflections); Basalt Quarry Bühl near Kassel, Germany [j]; Nic. + C Anhedral troilite (brownish tint), niningerite (white), silicates (dark); Indarch Enstatite Chondrite EH4, Shusha Elisavetpol, Azerbaidzhan [h]; Nic. //

282

Troilite A

31 μ

C

B

66 μ

13 μ

283

Pyrrhotite (Magnetopyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

igneous and metamorphic rocks brownish tints 36.91 - 41.56 Bireflectance: strong, dark brown to bluish grey weak to missing


A B C D E



Descriptions Anhedral pyrrhotite (brownish tint, bireflectance), small chalcopyrite grains (yellow); Mourts mine, Stillwater, USA [a]; Nic. // Pyrrhotite (dark brown to bluish grey anisotropy), chalcopyrite (dark); Mourts mine, Stillwater, USA [a]; Nic. + Pyrrhotite (grey to brown to reddish anisotropy), chalcopyrite (slightly olive); Mourts mine, Stillwater, USA [a]; Nic. + (+2°) Pyrrhotite (brownish grey shades) with corrugation lamellae; Karatunk mine, Urumqi, China [d]; Nic. // Replacement of pyrrhotite (elongated crystal) by marcasite (white) and pyrite (cream), sphalerite (medium grey), chalcopyrite (yellow); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. //

284

Pyrrhotite A

120 μ

C

B

250 μ

250 μ

D

E

250 μ

97 μ 285

Smythite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature oxidation product of FeS light pink [75] Bireflectance: strong, yellow and blue-grey strong, greyish yellow to reddish brown




Descriptions A Extremely thin platelet of smythite (light pink, about 220 μm wide and 2 μm thick) in calcite (darker grey); State Route 37 road cut, Bloomington, Indiana, USA [j]; Nic. // B Smythite platelets (reflection off surface is bright, other platelets appear dark) in calcite (milky internal reflections, double refraction lets crystals appear as phantom); State Route 37 road cut, Bloomington, Indiana, USA [j]; Nic. //

286

Smythite A

5μ

B

60 μ 287

Nickeline (Arsenical Nickel, Niccolite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Ag, Cu, and Ni arsenide and sulfide veins bright orange to pinkish 59.01 - 60.24 Bireflectance: distinct very strong, brown to blues, greenish to slate-grey orange to pinkish

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.20-Nickeline group and related compounds, Polarite-Cherepanovite series II/C.20-05 Sorosite Cu(Sn,Sb) II/C.20-10 Langisite (Co,Ni)As II/C.20-20 Nickeline NiAs II/C.20-30 Breithauptite NiSb II/C.20-40 Freboldite CoSe II/C.20-50 Sederholmite NiSe II/C.20-70 Hexatestibiopanickelite (Ni,Pd)(Te,Sb) II/C.20-75 Yuanjiangite AuSn II/C.20-80 Kotulskite Pd(Te,Bi) II/C.20-90 Sudburyite (Pd,Ni)Sb II/C.20-95 Stumpflite Pt(Sb,Bi) II/C.20-100 Polarite Pd(Bi,Pb) II/C.20-110 Sobolevskite PdBi II/C.20-120 Ruthenarsenite (Ru,Ni)As II/C.20-130 Cherepanovite RhAs

A B C D E

6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m mm2 6/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Interstitial anhedral nickeline (pinkish) in chromite (grey); Sierra de Ronda, Spain [c]; Nic. // Anhedral nickeline (orange, distinct bireflectance) intergrown with skutterudite (white); Zinkwand-Vöttern, Austria [b]; Nic. // Anhedral nickeline (brown to blue anisotropy), skutterudite (dark grey); Zinkwand-Vöttern, Austria [b]; Nic. + Radial nickeline (mottled orange, bireflectance) in rammelsbergite (white); Medenec (Kupferberg), Ústí Region, Czech Republic [a]; Nic. // Nickeline (bright turquoise to orange brown anisotropy), rammelsbergite (blue to brownish grey anisotropy); Medenec (Kupferberg), Ústí Region, Czech Republic [a]; Nic. +

288

Nickeline A

60 μ

C

B

250 μ

250 μ

D

E

125 μ

125 μ 289

Breithauptite (Hartmannite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal calcite veins associated with Co-Ni-Ag ores light copper red with violet tint 47.82 - 54.39 Bireflectance: pink to violet very noticeable, olive to brown, sometimes blue very distinct


A B

C D E


Descriptions Breithauptite (pink) intergrown with safflorite (almost white); Beresowsk, GUS [d]; Nic. // Anhedral breithauptite (slight pink to violet bireflectance) intergrown with nickeline (orange), small euhedral pyrite (slightly bluish cream), pyrargyrite on cracks (blue-grey); Cobalt, Ontario, Canada [a]; Nic. // Breithauptite (slightly olive to brown, sometimes blue anisotropy), nickeline (here brown), pyrite (isotropic), pyrargyrite (strong red internal reflections); Cobalt, Ontario, Canada [a]; Nic. + Two anhedral breithauptite grains (different pink shades), thin rim of safflorite (almost white; euhedral material also on right side); Beresowsk, GUS [d]; Nic. // Breithauptite (green and brown anisotropy), safflorite (almost isotropic); Beresowsk, GUS [d]; Nic. +

290

Breithauptite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 291

Freboldite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dolomite veinlets pinkish, darker than nickeline [40] Bireflectance: brownish to bluish, but less than nickeline



Descriptions A Massive freboldite (pinkish) and native selenium (bluish grey); artificial [j]; Nic. // B Freboldite (brownish to bluish anisotropy, fine lamellar twinning), native selenium (black, brown internal reflections); artificial [j]; Nic. +

292

Freboldite A

60 μ

B

60 μ 293

Polarite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Ni-Fe veins very light grey with yellowish tint 59.74 grey to brown

Bireflectance:



Descriptions A Oriented intergrowth of polarite (light grey, lamellar and myrmekitic) with plumbopalladinite (pink tint), rim of isoferroplatinum (white), cubanite (greenish brown tint), pentlandite (creamish brown); Majak Mine, Talnakh Norilsk, Urals, Russia [h]; Nic. // B Polarite (grey to brown anisotropy), plumbopalladinite (lighter brown), isoferroplatinum (light grey), cubanite (bluish grey anisotropy), pentlandite (medium grey); Majak Mine, Talnakh Norilsk, Urals, Russia [h]; Nic. +

294

Polarite A

24 μ

B

24 μ 295

Sobolevskite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

mooihoekite-chalcopyrite, troilite, and chalcopyrite-cubanite ores pinkish 55.95 - 61.45 Bireflectance: strong, pinkish grey and brown, reddish lilac, pale cream



Descriptions A Anhedral sobolevskite (pinkish tint), altaite (light grey with greenish tint, in and around sobolevskite), djerfisherite (medium grey with brown tint), chalcopyrite (brownish olive), galena (medium grey); Oktjabrsky, Norilsk, Russia [h]; Nic. // B Sobolevskite (grey with cream tint), altaite (dark greenish grey), djerfisherite (dark brown grey), chalcopyrite (dark olive), galena (isotropic); Oktjabrsky, Norilsk, Russia [h]; Nic. +

296

Sobolevskite A

24 μ

B

24 μ 297

Cherepanovite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

PGE placer from an ultramafic complex in an ophiolite belt, KoryakKamchatka region light cream 44.68 - 46.83 Bireflectance: dark brown to blue weak, yellow to pinkish hue and bluish white



Descriptions A Anhedral cherepanovite (light cream, irregular fractures) in cooperite (light greenish grey); Pekulney Massif, NE Russia [h]; Nic. // B Cherepanovite (dark brown to blue anisotropy), cooperite (bluish grey anisotropy); Pekulney Massif, NE Russia [h]; Nic. +

298

Cherepanovite A

10 μ

B

10 μ 299

Millerite (Hair Pyrites) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of sulfide deposits, limestones and dolomites, coal deposits pale to bright yellow 57.56 - 55.16 Bireflectance: strong, yellow to blue yellow

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.21-Millerite series II/C.21-10 Lapieite II/C.21-20 Mückeite II/C.21-25 Zlatogorite II/C.21-30 Millerite II/C.21-40 Makinenite

CuNiSbS3 CuNiBiS3 CuNiSb2 NiS NiSe

222 222 – 3 2/m – 3 2/m 3m

Descriptions A Anhedral millerite (cream to bright yellow, bireflectance) replacing ullmanite (lighter grey, top and bottom of picture), fahlore (?, darker grey inclusions in center); Müsen, Westphalia, Germany [b]; Nic. // B Millerite (yellow, brown, blue anisotropy), ullmanite (isotropic), fahlore (isotropic); Müsen, Westphalia, Germany [b]; Nic. + C Oriented intergrowth of millerite (slightly yellowish to cream pleochroism) and chalcopyrite (yellow); Ludwig-Vereinigt-Feld Mine, Oelsnitz, Saxony, Germany [a]; Nic. //

300

Millerite A

60 μ

C

B

50 μ

47 μ

301

Covellite (Covelline) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of sulfide Cu deposits, high temperature hydrothermal indigo-blue 3.44 - 19.17 Bireflectance: strong strong, orange shades marked, deep indigo-blue to blue-grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.22-Covellite series II/C.22-10 Covellite II/C.22-20 Klockmannite II/C.22-30 Idaite II/C.22-40 Nukundamite

CuS CuSe Cu5FeS6 (Cu,Fe)4S4

6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m – 3 2/m

Descriptions A Covellite (blue, strong bireflectance) replacing bornite (brownish relicts) and chalcopyrite (yellow lamellae); Avila, Salamanca, Spain [j]; Nic. // B Anhedral covellite (light to medium blue, twin lamellae, strong bireflectance); Bor, Serbia and Montenegro [b]; Nic. // C Covellite (strong orange anisotropy); Bor, Serbia and Montenegro [b]; Nic. +

302

Covellite A

10 μ

C

B

125 μ

125 μ

303

Klockmannite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal cream to greenish grey to blue 14.13 - 35.44 Bireflectance: strong, pale orange to greyish cream to greenish grey to blue

distinct



6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m – 3 2/m

Descriptions A Anhedral klockmannite aggregate (cream to bluish grey pleochroism, bireflectance) intergrown with umangite (violet, bireflectance); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. // B Klockmannite (light orange to brown anisotropy), umangite (dark orange to red-brown anisotropy); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. + C Klockmannite lamellae (blue grey) as alteration products of clausthalite (white), carbonate (dark grey); Predborice, Central Bohemia, Czech Republic [h]; Nic. //

304

Klockmannite A

24 μ

C

B

50 μ

21 μ

305

Idaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

lamellar alteration product of bornite copper-red to light orange 31.19 - 31.49 Bireflectance: strong, turquoise to reddish brown



6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m – 3 2/m

Descriptions A Lamellar replacement of idaite (light orange) by covellite (blue), relics of chalcopyrite (yellow); Cerro Huemul Mine, Argentina [e]; Nic. // B Idaite (turquoise to brownish grey anisotropy), chalcopyrite (dark), covellite (orange); Cerro Huemul Mine, Argentina [e]; Nic. +

306

Idaite A

29 μ

B

42 μ 307

Valleriite (Walleriite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of chalcopyrite in ultramafics medium brown to bluish grey 10.20 - 18.51 Bireflectance: strong, yellowish to brown strong, brown to bluish grey

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.23-Yushkinite-Vyalsovite series II/C.23-10 Yushkinite II/C.23-20 Valleriite II/C.23-30 Haapalaite II/C.23-40 Tochilinite II/C.23-50 Vyalsovite

A B C D

E

V1-xS·n(Mg,Al)(OH)2 4(Fe,Cu)S·3(Mg,Al)(OH)2 2(Fe,Ni)S·1.6(Mg,Fe)(OH)2 6Fe0.9S·5(Mg,Fe)(OH)2 FeS·Ca(OH)2·Al(OH)3

3m – 3 2/m – 3 2/m mono. 2/m 2/m 2/m

Descriptions Exsolution lamellae of valleriite (mottled brownish) in magnetite (medium grey); Palabora, South Africa [b]; Nic. // Anhedral valleriite (brown to bluish grey) in magnetite (medium grey); Palabora, South Africa [b]; Nic. // Anhedral valleriite (light brown anisotropy, very distinctive in larger grains) in magnetite (medium grey); Palabora, South Africa [b]; Nic. + Intergrowth of valleriite (bluish to brownish grey pleochroism, bireflectance) with cubanite (olive tinted grey), chalcopyrite (yellow), pentlandite (cream); Majak Mine, Talnakh, Norilsk, Urals, Russia [h]; Nic. // Valleriite (light brownish tinted to grey anisotropy), cubanite (dark violet anisotropy), chalcopyrite (dark), pentlandite (dark brown); Majak Mine, Talnakh, Norilsk, Urals, Russia [h]; Nic. +

308

Valleriite A

90 μ

C

B

99 μ

99 μ

D

E

36 μ

36 μ 309

Tochilinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

ultramafics, diamond pipes, carbonaceous chondrite meteorites, supergene U deposit orange to grey to yellowish grey 10.60 - 15.80 Bireflectance: strong, orange strong, orange to yellowish grey

strong



3m – 3 2/m – 3 2/m mono. 2/m 2/m 2/m

Descriptions A Tochilinite (bright orange anisotropy, compare covellite), goethite (here dark); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. + B Tochilinite (orange to grey, strong bireflectance, compare next photo), goethite (bluish grey); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. // C Tochilinite (orange to grey, strong bireflectance, compare previous photo), goethite (bluish grey); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. //

310

Tochilinite A

10 μ

C

B

20 μ

20 μ

311

Vyalsovite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

skarns violet grey to violet-red [14 - 20] Bireflectance: bright orange to red very strong, dark grey to purple

enhanced by colours



3m – 3 2/m – 3 2/m mono. 2/m 2/m 2/m

Descriptions A Massive vyalsovite (strong orange anisotropy), pyrite (isotropic), chalcopyrite (dark grey), valleriite (dark brownish grey anisotropy); Komsomolskaya Mine, Talnakh, Norilsk, Russia [h]; Nic. + B Massive vyalsovite (strong pleochroism from dark grey to purple, bireflectance), pyrite (light cream), chalcopyrite (light yellow), fine-grained valleriite (brownish grey pleochroism); Komsomolskaya Mine, Talnakh, Norilsk, Russia [h]; Nic. // C Massive vyalsovite (strong pleochroism from dark grey to purple, bireflectance; compare previous picture), pyrite (light cream), chalcopyrite (light yellow), fine-grained valleriite (brownish grey pleochroism); Komsomolskaya Mine, Talnakh, Norilsk, Russia [h]; Nic. //

312

Vyalsovite A

60 μ

C

B

125 μ

125 μ

313

Vulcanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Zn deposit containing tellurides, Au-Te deposits bright yellow to pink to blue 12.30 - 73.91 Bireflectance: strong very strong, white, yellow, violet, blue, greenish extreme, bright yellow to pink to blue

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.24-Vulkanite series II/C.24-10 Vulcanite

CuTe

2/m 2/m 2/m

Descriptions A Vulcanite (extreme anisotropy from white to yellow to violet to blue to greenish), rickardite (bluish grey anisotropy); artificial material [j]; Nic. + B Anhedral vulcanite (pleochroism here bright yellow, compare following photo) in rickardite matrix (cream, distinctive cleavage); artificial material [j]; Nic. // C Anhedral vulcanite (pleochroism here blue, compare previous photo), rickardite (cream, cleavage); artificial material [j]; Nic. //

314

Vulcanite A

120 μ

C

B

77 μ

77 μ

315

Braggite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

norites in layered mafic intrusives light grey 42.35 - 44.15 Bireflectance: distinct, in purplish and pinkish shades of grey and brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.25-Vysotskite-Cooperite series II/C.25-10 Vysotskite II/C.25-20 Braggite II/C.25-30 Cooperite

(Pd,Ni)S (Pt,Pd,Ni)S (Pt,Pd,Ni)S

4/m 4/m 4/m 2/m 2/m

Descriptions A Irregular braggite grain (light grey); Maandagshoek, South Africa [d]; Nic. // B Braggite (dark grey to brownish grey anisotropy, lamellae); Maandagshoek, South Africa [d]; Nic. +

316

Braggite A

24 μ

B

24 μ 317

Cooperite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

concentrates from norites brownish grey 37.53 - 45.83 Bireflectance: strong, bluish greys indistinct, white to creamy white to bluish white

Strunz Classification - Group Members - Chemical Formula - Crystallography II/C.25-Vysotskite-Cooperite series II/C.25-10 Vysotskite II/C.25-20 Braggite II/C.25-30 Cooperite

(Pd,Ni)S (Pt,Pd,Ni)S (Pt,Pd,Ni)S

4/m 4/m 4/m 2/m 2/m

Descriptions A Rim of cooperite (light grey) around chromite (medium grey) and as filling of fine cracks in rutheniridosmine (white); Pekulney Massif, NE Russia [h]; Nic. // B Rounded grain of cooperite (light grey) with rim of native platinum (cream-white); Maandagshoek, South Africa [d]; Nic. // C Cooperite (dark grey anisotropy), platinum (light grey, scratched); Maandagshoek, South Africa [d]; Nic. +

318

Cooperite A

60 μ

C

B

30 μ

30 μ

319

Linnaeite (Koboldine, Linneite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Ni-Co-sulfide veins light pink 44.93 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.01-Linneite group and related compounds II/D.01-10 Greigite Fe3S4 II/D.01-20 Linnaeite Co3S4 II/D.01-30 Polydymite Ni3S4 II/D.01-40 Carrollite Cu(Co,Ni)2S4 II/D.01-50 Fletcherite Cu(Ni,Co)2S4 II/D.01-60 Florensovite Cu(Cr1.5Sb0.5)S4 II/D.01-70 Violarite FeNi2S4 II/D.01-80 Siegenite (Ni,Co)3S4 II/D.01-90 Indite FeIn2S4 II/D.01-95 Cadmoindite CdIn2S4 II/D.01-100 Daubreelite FeCr2S4 II/D.01-110 Kalininite ZnCr2S4 II/D.01-120 Bornhardtite CoCo2Se4 II/D.01-130 Trüstedtite Ni3Se4 II/D.01-140 Tyrrellite (Cu,Co,Ni)3Se4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Massive linnaeite (pinkish grey) intergrown with pyrite (yellow tint), silicate (dark); Shinkolobwe Mine, Shaba, Congo [j]; Nic. // B Massive linnaeite (light pink) with fracture filling of sphalerite (medium grey), chalcopyrite (yellow), and small specs of galena (light grey) and tetrahedrite (greenish grey); Burbach near Müsen, Siegerland, Germany [g]; Nic. // C Linnaeite (dark), sphalerite (brown internal reflections), chalcopyrite (dark), galena (dark), tetrahedrite (dark); Burbach near Müsen, Siegerland, Germany [g]; Nic. +

320

Linnaeite A

60 μ

C

B

250 μ

250 μ

321

Polydymite (Nickel-Linneite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins cream-white with bluish tint 47.55 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.01-Linneite group and related compounds II/D.01-10 Greigite Fe3S4 II/D.01-20 Linnaeite Co3S4 II/D.01-30 Polydymite Ni3S4 II/D.01-40 Carrollite Cu(Co,Ni)2S4 II/D.01-50 Fletcherite Cu(Ni,Co)2S4 II/D.01-60 Florensovite Cu(Cr1.5Sb0.5)S4 II/D.01-70 Violarite FeNi2S4 II/D.01-80 Siegenite (Ni,Co)3S4 II/D.01-90 Indite FeIn2S4 II/D.01-95 Cadmoindite CdIn2S4 II/D.01-100 Daubreelite FeCr2S4 II/D.01-110 Kalininite ZnCr2S4 II/D.01-120 Bornhardtite CoCo2Se4 II/D.01-130 Trüstedtite Ni3Se4 II/D.01-140 Tyrrellite (Cu,Co,Ni)3Se4


Descriptions A Massive polydymite (cream-white, regular cracks); Kasa Divrigi mine, Divrik, Turkey [b]; Nic. // B Massive polydymite (bluish tinted cream), pyrite (yellowish tint); Nkana, Zambia [a]; Nic. //

322

Polydymite A

60 μ

B

60 μ 323

Carrollite (Synchnodymite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins cream-white 41.99 Bireflectance: (45.4 nickelian) isotropic, rarely slight anisotropy

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.01-Linneite group and related compounds II/D.01-10 Greigite Fe3S4 II/D.01-20 Linnaeite Co3S4 II/D.01-30 Polydymite Ni3S4 II/D.01-40 Carrollite Cu(Co,Ni)2S4 II/D.01-50 Fletcherite Cu(Ni,Co)2S4 II/D.01-60 Florensovite Cu(Cr1.5Sb0.5)S4 II/D.01-70 Violarite FeNi2S4 II/D.01-80 Siegenite (Ni,Co)3S4 II/D.01-90 Indite FeIn2S4 II/D.01-95 Cadmoindite CdIn2S4 II/D.01-100 Daubreelite FeCr2S4 II/D.01-110 Kalininite ZnCr2S4 II/D.01-120 Bornhardtite Co3Se4 II/D.01-130 Trüstedtite Ni3Se4 II/D.01-140 Tyrrellite (Cu,Co,Ni)3Se4


Descriptions A Anhedral carrolite (white, cracks) in chalcopyrite (yellow) and bornite (pinkish brown); Nkana mine, Zambia [b]; Nic. // B Anhedral carrolite (creamish white), alteration replaced by covellite (blue); Kolwezi mine, Katanga, Congo [d]; Nic. //

324

Carrollite A

120 μ

B

60 μ 325

Violarite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal light grey with pink tint 44.03 (48.9 cobaltian) isotropic

Bireflectance:



Descriptions A Pentlandite (cream, cleavage cracks) replaced by violarite (grey), pyrrhotite (brownish grey), chalcopyrite (yellow); Kabanga, Tanzania [d]; Nic. // B Violarite (pink tint) and pyrite (yellowish tint) replacing pentlandite (creme), chalcopyrite (yellow), carbonates (dark grey); Scotia, Australia [a]; Nic. // C Violarite (dark brownish grey), pyrite (dark grey), chalcopyrite (dark olive grey), carbonates (white internal reflections), goethite (light brown internal reflections); Scotia, Australia [a]; Nic. +

326

Violarite A

20 μ

C

B

75 μ

75 μ

327

Siegenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Ni-Fe sulfide veins very light grey with pink tint 47.82 (48.1 cuprian) isotropic

Bireflectance:



Descriptions A Massive siegenite (very light grey with pink tint), irregular patches of pyrite (light cream); Shinkolobwe, Katanga, Congo [d]; Nic. // B Siegenite (isotropic), pyrite (isotropic); Shinkolobwe, Katanga, Congo [d]; Nic. +

328

Siegenite A

120 μ

B

120 μ 329

Indite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, replacing botryoidal cassiterite light grey with bluish tint 26.07 isotropic

Bireflectance:



Descriptions A Rounded indite grain (light grey with bluish tint), partially altered to dzhalindite (dark grey), quartz (slightly darker grey than dzhalindite); Dzhalindin deposit, Little Khingan Ridge, Far Eastern Region, USSR [j]; Nic. // B Indite (isotropic), dzhalindite (brown internal reflections), quartz (milky internal reflections); Dzhalindin deposit, Little Khingan Ridge, Far Eastern Region, USSR [j]; Nic. +

330

Indite A

40 μ

B

40 μ 331

Daubreelite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

meteorites medium grey 32.86 isotropic

Bireflectance:



Descriptions A Euhedral daubreelite (medium grey) intergrown with schöllhornite (here very similar grey, round extension left of daubreelite) in troilite (light brownish tint), schreibersite (light cream); Indarch meteorite, Shusha, Elisavetpol, Azerbaidzhan [h]; Nic. // B Daubreelite (bluish black), schöllhornite (similar shade), troilite (dark brownish grey), schreibersite (dark brown); Indarch meteorite, Shusha, Elisavetpol, Azerbaidzhan [h]; Nic. +

332

Daubreelite A

5μ

B

5μ 333

Bornhardtite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal light pinkish grey 49.43 isotropic

Bireflectance:



Descriptions A Anhedral bornhardtite grains (pink) in clausthalite (light grey), hematite (medium grey); Eskaborner Berg, Tilkerode, Germany [g]; Nic. //

334

Bornhardtite A

19 μ

335

Tyrrellite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late hydrothermal replacements and open space fillings in sheared Precambrian rocks cream 47.89 isotropic

Bireflectance:



Descriptions A Euhedral tyrrellite (cream) in umangite matrix (violet to greenish grey pleochroism, bireflectance), eucairite (darker cream, around tyrrelite and as fine inclusions in umangite); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. // B Tyrrellite (isotropic), umangite (dark orange to red-brown anisotropy), eucairite (dark, slightly anisotropic); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. +

336

Tyrrellite A

48 μ

B

48 μ 337

Cuprorhodsite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alluvial deposits on the Aldan Shield and Kamchatka medium grey 36.95 - 39.1 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.02-Dayingite-Xingzhongite series II/D.02-10 Dayingite II/D.02-20 Cuprorhodsite II/D.02-30 Cuproiridsite II/D.02-40 Malanite II/D.02-45 Ferrorhodsite II/D.02-50 Xingzhongite

CuCoPtS4 CuRh2S4 CuIr2S4 Cu(Pt,Ir)2S4 (Fe,Cu)(Rh,Ir,Pt)2S4 (Pb,Cu,Fe)(Ir,Pt,Rh)2S4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Cuprorhodsite (slightly lighter than adjacent grain) intergrown with miassite (light grey, larger section), cooperite with rim of native platinum (upper right corner, greenish grey and white, respectively); Maandagshoek, South Africa [d]; Nic. // B Cuprorhodsite and miassite are practically indistinguishable (medium to dark grey), cooperite (darker than miassite), native platinum (strongly scratched and lighter); Maandagshoek, South Africa [d]; Nic. +

338

Cuprorhodsite A

18 μ

B

18 μ 339

Cuproiridsite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alluvial deposits on the Aldan Shield and Kamchatka medium grey 32.97 - 37.59 isotropic

Bireflectance:



– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Rim of cuproiridsite (medium grey) around isoferroplatinum (slightly tinted white), angular inclusions of iridium (white); Inagly Massif, Aldan Shield, Russia [h]; Nic. // B Cuproiridsite (darkest grey), isoferroplatinum (brownish grey), iridium (brown spots); Inagly Massif, Aldan Shield, Russia [h]; Nic. +

340

Cuproiridsite A

10 μ

B

10 μ 341

Malanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

peridotite-type Pt ores with Cu-Ni sulfides light grey with brownish tint [45] isotropic

Bireflectance:



– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Anhedral malanite (light grey) in isoferroplatinum (tinted white), erlichmanite (medium grey, slightly darker than malanite, linearly oriented); Konder Massif, Aldan Shield, Russia [h]; Nic. // B Malanite (dark grey), isoferroplatinum (dark brownish grey), erlichmanite (dark grey); Konder Massif, Aldan Shield, Russia [h]; Nic. +

342

Malanite A

10 μ

B

10 μ 343

Kashinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

placers from ultramafic rocks light grey with brownish tint 47.51 - 46.25 Bireflectance: moderate, reddish-violet to brownish tints weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.06-Kashinite series II/D.06-10 Kashinite II/D.06-20 Bowieite II/D.06-30 Daomanite

(Ir,Rh)2S3 (Rh,Ir,Pt)1.77S3 CuPtAsS2

2/m 2/m 2/m 2/m 2/m 2/m mm2

Descriptions A Anhedral kashinite (light grey with brownish tint) next to erlichmanite (light grey with bluish tint) in isoferroplatinum (creamish white); Nishne Tagilsk, Urals, Russia [h]; Nic. // B Kashinite (brownish grey), erlichmanite (darkest mineral), isoferroplatinum (brownish grey); Nishne Tagilsk, Urals, Russia [h]; Nic. +

344

Kashinite A

24 μ

B

24 μ 345

Bowieite (Sulrhodite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt alloy nuggets pale grey to pale grey-brown 46.56 - 48.25 Bireflectance: weak, dark grey to very dark brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.06-Kashinite series II/D.06-10 Kashinite II/D.06-20 Bowieite II/D.06-30 Daomanite

(Ir,Rh)2S3 (Rh,Ir,Pt)1.77S3 CuPtAsS2

2/m 2/m 2/m 2/m 2/m 2/m mm2

Descriptions A Irregular grain of bowieite (light grey) intergrown with cuprorhodsite (slightly darker); Maandagshoek, South Africa [d]; Nic. // B Bowieite (dark grey); cuprorhodsite (slightly lighter); Maandagshoek, South Africa [d]; Nic. +

346

Bowieite A

12 μ

B

12 μ 347

Edgarite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

fenitised xenolith in nepheline syenite, Kola Peninsula brownish grey, similar to graphite 27.00 - 38.50 Bireflectance: distinct strong, almost white to dark brown distinct, grey to light grey with bluish tint

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.07-Paxite series II/D.07-10 Paxite II/D.07-20 Edgarite

CuAs2 FeNb3S6

2/m 622

Descriptions A Spheroidal edgarite (dark brownish grey, bireflectance) intergrown with pyrrhotite (light brown) and marcasite (cream), silicates (dark grey); Chibiny, Kola Peninsula, Russia [h]; Nic. / / B Edgarite (strong light to dark brown anisotropy), pyrrhotite (brownish grey), marcasite (blue grey), silicates (white and multicolour internal reflections); Chibiny, Kola Peninsula, Russia [h]; Nic. +

348

Edgarite A

19 μ

B

19 μ 349

Stibnite (Antimonite, Antimony Glance) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, submarine hydrothermal light to brownish grey 30.98 - 45.01 Bireflectance: strong, brown to blue grey light to brownish grey

distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.08-Stibnite-Bismuthinite series II/D.08-10 Paakkonenite II/D.08-20 Stibnite II/D.08-25 Antimonselite II/D.08-30 Metastibnite II/D.08-40 Bismuthinite II/D.08-50 Guanajuatite II/D.08-60 Ottemannite

A B C D E

Sb2AsS2 Sb2S3 Sb2Se3 Sb2S3 Bi2S3 Bi2Se3 Sn2S3

2/m 2/m 2/m 2/m 2/m 2/m 2/m none 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Massive stibnite aggregate (different grey shades, lamellar twinning); Mariengrube, Nikolsdorf, Austria [b]; Nic. // Stibnite (bluish to brownish grey, lamellar twinning); Mariengrube, Nikolsdorf, Austria [b]; Nic. + Stibnite (bluish to brownish grey, lamellar twinning); Mariengrube, Nikolsdorf, Austria [b]; Nic. + Skeletal hollow stibnite (light grey) and colloform pyrite (cream) in amorphous silica matrix (dark grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Stibnite (grey anisotropy), realgar (bright yellow), pyrite (isotropic), amorphous silica (white internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

350

Stibnite A

60 μ

C

B

125 μ

250 μ

D

E

33 μ

174 μ 351

Bismuthinite (Bismuth Glance, Bismutolamprite) Geologic Environment:

Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to high-temperature hydrothermal veins, tourmaline-bearing Cu deposits in granite, some high temperature Au veins, volcanic exhalations medium grey 36.91 - 48.77

Bireflectance:

very faint to strong


A B

C

D E



Descriptions Euhedral bismuthinite rim (bluish greys, strong bireflectance) around native gold (yellow) in matrix of stannite (light olive); Huallatani Mine, Bolivia [c]; Nic. // Massive bismuthinite (blue grey shades, slight bireflectance) with inclusions of quartz crystals (dark grey), native bismuth (light cream), and stannite (grey with greenish tint); Huallatani Mine, Bolivia [c]; Nic. // Bismuthinite (blue grey to brownish grey anisotropy), quartz (black), native bismuth (grey shades anisotropy), stannite (dark brown to blue anisotropy); Huallatani Mine, Bolivia [c]; Nic. + Twin lamellae of bismuthinite (grey shades, bireflectance); Huallatani Mine, Bolivia [c]; Nic. // Bismuthinite (lamellae with dark and bluish grey anisotropy); Huallatani Mine, Bolivia [c]; Nic. +

352

Bismuthinite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 353

Guanajuatite (Frenzelite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal deposits light grey with yellowish hue 42.57 - 52.2 Bireflectance: strong, bluish to brownish grey distinct

slight




Descriptions A Guanajuatite (light grey, slight bireflectance), fine platelets of lepidocrocite (light grey) in quartz (dark grey, euhedral), alteration products, such as klockmannite (bluish to grey pleochroism) and bismite (medium grey); Nuestra Señora de la Luz, Leon, Guanajuato, Mexico [j]; Nic. // B Guanajuatite (bluish to brownish grey anisotropy), lepidocrocite (red internal reflections), quartz (colourless), klockmannite (orange anisotropy), bismite (white to orange internal reflections); Nuestra Señora de la Luz, Leon, Guanajuato, Mexico [j]; Nic. +

354

Guanajuatite A

60 μ

B

60 μ 355

Ottemannite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zones of hydrothermal Sn deposits medium grey orange-brown [15] Bireflectance: strong, but difficult to discern blue to violet weak




Descriptions A Fibrous ottemannite (patchy greys, some undulating crystals) replacing herzenbergite (light grey), cassiterite (medium grey, euhedral), quartz (large dark grey crystals); Maria Theresia mine, Huari, Bolivia [g]; Nic. // B Ottemannite (difficult to discern blue to violet anisotropy, small brown internal reflections), herzenbergite (dark blue and brown anisotropy), cassiterite (bright internal reflections), quartz (white and multicolour internal reflections); Maria Theresia mine, Huari, Bolivia [g]; Nic. +

356

Ottemannite A

24 μ

B

24 μ 357

Tellurantimony Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Zn-rich stratiform massive sulfide deposit light pink to cream 65.05 - 64.85 Bireflectance: moderate, pinkish greys weak, pink to cream

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.09-Tetradymite group, Tellurantimony-Kawazulite series II/D.09-10 Tellurantimony Sb2Te3 II/D.09-20 Tellurobismuthite Bi2Te3 II/D.09-30 Paraguanajuatite Bi2(Se,S)3 II/D.09-50 Skippenite Bi2Se2(Te,S) II/D.09-60 Tetradymite Bi2Te2S II/D.09-70 Kawazulite Bi2(Te,Se,S)3

– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Tellurantimony (light pink lath), in altaite (light grey with greenish tint), cobaltite (light pink), silicates (dark grey); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. // B Tellurantimony (pinkish grey anisotropy), altaite (isotropic, many scratches), cobaltite (isotropic, darkest phase), silicates (green to white internal reflections); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. +

358

Tellurantimony A

40 μ

B

40 μ 359

Tellurobismuthite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

complex Au- and Te-bearing metamorphosed high-sulfidation VMS deposits light grey 60.53 - 63.47 Bireflectance: weak, dark brownish to greenish grey


– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Massive tellurobismuthite (medium grey) replacing calaverite (cream); Cripple Creek, Colorado, USA [e]; Nic. // B Tellurobismuthite (mottled dark greenish to brownish grey anisotropy), calaverite (brownish grey); Cripple Creek, Colorado, USA [e]; Nic. +

360

Tellurobismuthite A

47 μ

B

47 μ 361

Paraguanajuatite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

contact metamorphic, hydrothermal veins white 50.28 - 53.98 Bireflectance: distinct, dark brownish grey distinct


– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Intergrowth of paraguanajuatite (white) and weibullite (tinted grey, bireflectance), chalcopyrite (dull yellow), gold (yellow), quartz (dark grey); Falu mine, Falun, Dalarna, Sweden [j]; Nic. // B Lamellar intergrowth of paraguanajuatite (white and grey pleochroism, the latter shade is very similar to its neighbour) and weibullite (light cream-grey), quartz (dark grey); Falu mine, Falun, Dalarna, Sweden [j]; Nic. // C Paraguanajuatite (here darkest brownish grey anisotropy), weibullite (lighter brownish grey shades anisotropy), quartz (clear and multicolour internal reflections); Falu mine, Falun, Dalarna, Sweden [j]; Nic. +

362

Paraguanajuatite A

42 μ

C

B

46 μ

46 μ

363

Tetradymite (Bornine, Daphyllite, Eutomite, Xaphyllite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate- to high-temperature hydrothermal Au-quartz veins, contact metamorphic greenish grey 53.45 - 56.65 Bireflectance: weak, darker grey shades


– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Irregular mass of tetradymite (greenish grey, various cracks), native bismuth (cream tint), chalcopyrite (light olive), Bi-carbonate (?, medium grey, slight bireflectance); Boliden, Sweden [e]; Nic. // B Tetradymite (darker grey shades, slight anisotropy), native bismuth (pinkish grey, scratches), chalcopyrite (here almost like tetradymite), Bi-carbonate (?, light internal reflections); Boliden, Sweden [e]; Nic. +

364

Tetradymite A

60 μ

B

60 μ 365

Joséite (Grünlingite, Gruetite, Oruetite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granular limestone cream-white 56.30 - 61.24 Bireflectance: moderate, brownish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.11-Tetradymite group, Ikunolite-Joséeite-B series II/D.11-10 Ikunolite Bi4(S,Se)3 II/D.11-20 Laitakarite Bi4(Se,S)3 II/D.11-30 Joséeite Bi4(S,Te)3 II/D.11-35 Joséeite-B Bi4(S,Te)3 II/D.11-40 Pilsenite Bi4Te3

– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Anhedral joséite (cream-white) intergrown with bismuthinite (light grey) and gold (yellow, many scratches), quartz (dark grey); Glacier Gulch, Hudson Bay Mts., Smithers, British Columbia, Canada [j]; Nic. // B Massive joséite (cream-white) intergrown with bismuthinite (light grey), quartz (dark grey); Glacier Gulch, Hudson Bay Mts., Smithers, British Columbia, Canada [j]; Nic. // C Joséite (dark brownish grey anisotropy, many scratches), bismuthinite (here lighter than joséite), quartz (milky internal reflections); Glacier Gulch, Hudson Bay Mts., Smithers, British Columbia, Canada [j]; Nic. +

366

Joséite A

40 μ

C

B

125 μ

125 μ

367

Pilsenite (Wehrlite = mixture of Pilsenite and Hessite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal light bluish grey 36.9 Bireflectance: dark bluish and brownish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.11-Tetradymite group, Ikunolite-Joséeite-B series II/D.11-10 Ikunolite Bi4(S,Se)3 II/D.11-20 Laitakarite Bi4(Se,S)3 II/D.11-30 Joséeite Bi4(S,Te)3 II/D.11-35 Joséeite-B Bi4(S,Te)3 II/D.11-40 Pilsenite Bi4Te3

– 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Subhedral prismatic pilsenite (light bluish grey), sphalerite (medium grey), carbonate (dark grey); Nagybörzsöny (Deutsch Pilsen), Börzsöny Mts., Hungary [j]; Nic. // B Pilsenite (dark bluish and brownish grey anisotropy), sphalerite (light to medium brown internal reflections), carbonate (milky to multicolour internal reflections); Nagybörzsöny (Deutsch Pilsen), Börzsöny Mts., Hungary [j]; Nic. +

368

Pilsenite A

60 μ

B

60 μ 369

Montbrayite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

with other tellurides, sulfides, and Au light grey [45] Bireflectance: weak weak to moderate, grey, yellow, brown, blue weak, bluish to pinkish tinted greys

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.15-Montbrayite-Buckhornite series II/D.15-10 Montbrayite II/D.15-20 Nagyagite II/D.15-30 Buckhornite

(Au,Sb)2Te3 AuPb(Sb,Bi)Te2-3S6 AuPb2BiTe2S3

– 1 – 4 2/m 2/m 2/m

Descriptions A Anhedral montbrayite (light pinkish grey), tellurobismuthite (slight greenish grey), coloradoite (medium grey), frohbergite (medium brownish grey), gold (yellow); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. // B Massive montbrayite (very light grey, bireflectance, conchoidal fracture); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. // C Montbrayite (grey, brown, and blue anisotropy, many scratches); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. +

370

Montbrayite A

60 μ

C

B

125 μ

125 μ

371

Nagyagite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

epithermal hydrothermal veins light to bluish grey 37.28 - 41.23 Bireflectance: weak but distinct, bluish to brownish weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.15-Montbrayite-Buckhornite series II/D.15-10 Montbrayite II/D.15-20 Nagyagite II/D.15-30 Buckhornite

(Au,Sb)2Te3 AuPb(Sb,Bi)Te2-3S6 AuPb2BiTe2S3

– 1 – 4 2/m 2/m 2/m

Descriptions A Euhedral laths of nagyagite (light grey) and krennerite (cream-white) in alabandite matrix (medium grey); Nagyag, Romania [e]; Nic. // B Nagyagite (bluish to brownish anisotropy, partially lamellar twinning), krennerite (brownish grey), alabandite (darkest grey); Nagyag, Romania [e]; Nic. +

372

Nagyagite A

60 μ

B

60 μ 373

Sylvanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal veins; late mineral in moderate- to high-temperature deposits white to light cream 51.14 - 61.65 Bireflectance: weak strong, grey, brown, blue strong, cream-white to light leather-brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.16-Kostovite-Calaverite series II/D.16-10 Kostovite II/D.16-20 Sylvanite II/D.16-30 Krennerite II/D.16-40 Calaverite

CuAuTe4 (Au,Ag)2Te4 AuTe2 AuTe2

mm2 2/m mm2 2/m

Descriptions A Massive sylvanite (white to light cream, polysynthetic twin lamellae, bireflectance), small nagyagite grains (medium grey), carbonate crystals (dark grey); Nagyag, Romania [g]; Nic. // B Sylvanite (grey, brown, blue anisotropy), nagyagite (dark grey), carbonate (colourless internal reflections); Nagyag, Romania [g]; Nic. + C Euhedral sylvanite (white to light cream, polysynthetic twin lamellae, bireflectance), nagyagite (bluish grey), carbonate crystals (dark grey); Nagyag, Romania [g]; Nic. //

374

Sylvanite A

60 μ

C

B

125 μ

103 μ

375

Krennerite (Bunsenine, Müllerine) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


hydrothermal veins cream-white 61.28 - 63.18 Bireflectance: (56.2 - 60.65 argentian) strong, to dark brown weak



mm2 2/m mm2 2/m

Descriptions A Krennerite (cream-white) intergrown with nagyagite (medium grey), carbonate (darker grey) and quartz (almost black euhedral crystals); Nagyag, Rumania [e]; Nic. // B Anhedral krennerite (cream-white) with inclusions of relict nagyagite lamellae (medium grey) and alabandite (darker grey, lower left) with pyrolusite (cream) on fractures; Nagyag, Rumania [e]; Nic. // C Krennerite (darker grey), nagyagite (darker grey than krennerite), alabandite (almost black); Nagyag, Rumania [e]; Nic. +

376

Krennerite A

49 μ

C

B

82 μ

82 μ

377

Calaverite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal veins, moderate- to high-temperature hydrothermal deposits very light cream 63.46 - 67.92 Bireflectance: weak, light and dark brownish greys weak



mm2 2/m mm2 2/m

Descriptions A Anhedral calaverite (light cream) replaced by unknown isotropic mineral (medium grey), quartz (dark); Cripple Creek, Colorado, USA [e]; Nic. // B Anhedral calaverite (light cream) in quartz (dark); Cripple Creek, Colorado, USA [e]; Nic. // C Calaverite exhibiting rare twinning (light and dark brownish greys anisotropy) in quartz (grey and multi-colour internal reflections); Cripple Creek, Colorado, USA [e]; Nic. +

378

Calaverite A

42 μ

C

B

125 μ

125 μ

379

Villamaninite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dolostones, dolomite veinlets light blue-grey to violet grey 23.63 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.17-Pyrite group and related compounds, Fukuchilite-Michenerite series II/D.17-10 Fukuchilite Cu3FeS8 II/D.17-20 Villamaninite (Cu,Ni,Co,Fe)S2 II/D.17-30 Pyrite FeS2 II/D.17-40 Cattierite CoS2 II/D.17-50 Vaesite NiS2 II/D.17-60 Hauerite MnS2 II/D.17-65 Dzharkenite FeSe2 II/D.17-70 Krutaite CuSe2 II/D.17-80 Trogtalite CoSe2 II/D.17-90 Penroseite (Ni,Co,Cu)Se2 II/D.17-100 Laurite RuS2 II/D.17-110 Erlichmanite OsS2 II/D.17-120 Sperrylite PtAs2 II/D.17-130 Aurostibite AuSb2 II/D.17-140 Geversite Pt(Sb,Bi)2 II/D.17-150 Insizwaite Pt(Bi,Sb)2 II/D.17-153 Changchengite IrBiS II/D.17-155 Mayingite IrBiTe II/D.17-160 Maslovite PtBiTe II/D.17-170 Testibiopalladite PdTe(Sb,Te) II/D.17-175 Padmaite PdBiSe II/D.17-180 Michenerite (Pd,Pt)BiTe

– 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 – 2/m 3 23 – 2/m 3 23 23 23 23

Descriptions A Altered villamaninite (bluish grey), chalcopyrite (yellow), small specs of covellite (blue), carbonate (dark grey); Providencia Mine, Villamanin, Cármenes District, Spain [a]; Nic. // B Villamaninite (isotropic, dark grey), chalcopyrite (dark), covellite (orange anisotropy), carbonate (white and yellow stained internal reflections), malachite and chrysocolla (green to turquoise internal reflections); Providencia Mine, Villamanin, Cármenes District, Spain [a]; Nic. //

380

Villamaninite A

60 μ

B

60 μ 381

Pyrite (Fool’s Gold) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy:

sedimentary, magmatic, metamorphic, hydrothermal cream to white 55.09 Bireflectance: isotropic, occasionally slightly anisotropic with tints of violet, brown, and turquoise

Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.17-Pyrite group and related compounds, Fukuchilite-Michenerite series II/D.17-10 Fukuchilite Cu3FeS8 II/D.17-20 Villamaninite (Cu,Ni,Co,Fe)S2 II/D.17-30 Pyrite FeS2 II/D.17-40 Cattierite CoS2 II/D.17-50 Vaesite NiS2 II/D.17-60 Hauerite MnS2 II/D.17-65 Dzharkenite FeSe2 II/D.17-70 Krutaite CuSe2 II/D.17-80 Trogtalite CoSe2 II/D.17-90 Penroseite (Ni,Co,Cu)Se2 II/D.17-100 Laurite RuS2 II/D.17-110 Erlichmanite OsS2 II/D.17-120 Sperrylite PtAs2 II/D.17-130 Aurostibite AuSb2 II/D.17-140 Geversite Pt(Sb,Bi)2 II/D.17-150 Insizwaite Pt(Bi,Sb)2 II/D.17-153 Changchengite IrBiS II/D.17-155 Mayingite IrBiTe II/D.17-160 Maslovite PtBiTe II/D.17-170 Testibiopalladite PdTe(Sb,Te) II/D.17-175 Padmaite PdBiSe II/D.17-180 Michenerite (Pd,Pt)BiTe

A B C D E


Descriptions Pyrite cube (cream-white) in carbonate (dark grey), pyrrhotite (brownish cream); Morro Velho, Minas Gerais, Brazil [b]; Nic. // Cataclastic pyrite (white) partially replaced by chalcopyrite (yellow); Cerro Huemul Mine, Argentina [e]; Nic. // Radial pyrite (confirmed by XRD, anomalous anisotropy, dark grey with tints of violet, brown, and turquoise); Wetterstein, Eastern Alps, Germany [a]; Nic. + Framboidal pyrite (cream), barite crystals (greyish); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Colloform pyrite (cream, desiccation cracks), galena (light grey, cleavage breakouts), ilmenite (brownish grey, bireflectance), silicates (dark grey); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. //

382

Pyrite A

239 μ

C

B

61 μ

254 μ

D

E

12 μ

83 μ 383

Cattierite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

carbonates associated with U-Cu-Co-Ni ores pinkish grey 38.85 isotropic

Bireflectance:



Descriptions A Cattierite (pinkish grey) replaces pyrite (cream, incomplete replacements show more brownish colours); Kasolo Mine, Shinkolobwe, Shaba, Congo [j]; Nic. // B Cataclastic cattierite (pinkish grey, cleavage), partially replacing pyrite (light yellow) in diffuse seams; Kasolo Mine, Shinkolobwe, Shaba, Congo [j]; Nic. // C Cattierite (dark brownish grey, cleavage), pyrite (dark grey with greenish tint); Kasolo Mine, Shinkolobwe, Shaba, Congo [j]; Nic. +

384

Cattierite A

60 μ

C

B

125 μ

125 μ

385

Vaesite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


disseminations in dolomite, alteration product of nickel-skutterudite grey with pale violet tint 31.55 (31.8 cobaltian, Bireflectance: 33.2 cuprian, 33.8 selenian) isotropic, occasionally slightly dark brown-grey anisotropy



Descriptions A Massive vaesite (medium grey with pale violet tint, many fractures along two major cleavage plains) replacing linnaeite (pinkish grey), pyrite (yellow tint, brittle cracks); Shinkolobwe Mine, Shaba, Congo [j]; Nic. // B Subhedral vaesite (medium grey with pale violet tint) replaces linnaeite (pinkish grey), radial molybdenite (strong grey bireflectance), silicate (dark grey); Shinkolobwe Mine, Shaba, Congo [j]; Nic. //

386

Vaesite A

60 μ

B

60 μ 387

Hauerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature solfataric waters, marine salt deposits, clay deposits rich in sulfur, altered extrusives bluish grey dark red 23.53 Bireflectance: isotropic



Descriptions A Large hauerite crystal (bluish grey, distinctive cleavage at {100}); Kalinka, Javorie Mts., Slovak Republic [j]; Nic. // B Hauerite (isotropic, dark red internal reflections in thin portions); Kalinka, Javorie Mts., Slovak Republic [j]; Nic. +

388

Hauerite A

60 μ

B

60 μ 389

Penroseit (Blackeite, Blockite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins cream 42.23 (39.6 cuprian) isotropic

Bireflectance:



Descriptions A Anhedral penroseite (cream), linnaeite (lighter cream), vaesite (medium grey), fine-grained radially crystallised molybdenite (darker grey); Shinkolobwe Mine, Shaba, Congo [j]; Nic. // B Anhedral penroseite (cream) in linnaeite (here almost yellowish impression), vaesite (medium grey); Shinkolobwe Mine, Shaba, Congo [j]; Nic. // C Penroseite (lightest of the dark brown shades), linnaeite (very dark and similar to vaesite), vaesite (very dark); Shinkolobwe Mine, Shaba, Congo [j]; Nic. +

390

Penroseit A

40 μ

C

B

50 μ

50 μ

391

Laurite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

ultramafic complexes and their placers medium grey 38.73 isotropic

Bireflectance:



Descriptions A Euhedral laurite (medium grey) intergrown with isoferroplatinum (light cream), inclusions of rhodarsenide (light olive) and osmium (light grey); Maandagshoek, South Africa [d]; Nic. // B Laurite (dark), isoferroplatinum (brownish grey), rhodarsenide (similar to isoferroplatinum; olive), osmium (darker brown); Maandagshoek, South Africa [d]; Nic. + C Anhedral laurite (light grey) in chromite (medium grey); Kraubath, Austria [d]; Nic. //

392

Laurite A

18 μ

C

B

38 μ

50 μ

393

Erlichmanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

noble metal placers light grey 42.27

Bireflectance:



Descriptions A Euhedral erlichmanite (grey) in isoferroplatinum (cream tint); Rio Santiago, Esmeraldas, Ecuador [d]; Nic. // B Erlichmanite (dark grey), isoferroplatinum (brownish grey, scratched); Rio Santiago, Esmeraldas, Ecuador [d]; Nic. +

394

Erlichmanite A

15 μ

B

60 μ 395

Sperrylite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic, basic pegmatites, alluvial deposits white 55.07 isotropic

Bireflectance:



Description A Euhedral sperrylite (white) in bornite (brownish with violet tinge); Norilsk, Urals, Russia [h]; Nic. //

396

Sperrylite A

5μ

397

Aurostibite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Au-quartz veins white with pink tint 62.38 isotropic

Bireflectance:



Descriptions A Aurostibite (light grey) as rim between gold (yellow) and chalcopyrite (tanned yellow), tetrahedrite (greenish grey), quartz (dark grey); Rycon Mine, Yellowknife, Mackenzie District, Northwest Territories, Canada [j]; Nic. // B Aurostibite (light grey), gold (yellow), chalcopyrite (tanned yellow), tetrahedrite (isotropic), quartz (multicolour internal reflections); Rycon Mine, Yellowknife, Mackenzie District, Northwest Territories, Canada [j]; Nic. +

398

Aurostibite A

60 μ

B

60 μ 399

Geversite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Pt concentrates from Pt-Fe-Ni-Cu deposits in ultramafic rocks light bluish grey 57.62 isotropic

Bireflectance:



Descriptions A Regular intergrowths (exsolutions?) of geversite (light bluish grey) and cabriite (pinkish brown), parkerite (upper rim, medium greys bireflectance), niggliite (cream to blue grey; strong bireflectance), chalcopyrite (olive), galena (slightly darker medium grey), native silver (white); Oktjabrsky, Norilsk, GUS [d]; Nic. // B Geversite (dark blue grey), cabriite (red brown to brown anisotropy), parkerite (grey anisotropy), niggliite (strong bright cream to blue anisotropy), chalcopyrite (dark olive), galena (isotropic), native silver (medium grey); Oktjabrsky, Norilsk, GUS [d]; Nic. +

400

Geversite A

60 μ

B

60 μ 401

Insizwaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal vein light brown 54.49 isotropic

Bireflectance:



Descriptions A Exsolution of insizwaite (small elliptical grains, brown) in froodite (here cream), small specs of native silver (white) in altaite (greenish tint; partially replacing insizwaite), chalcopyrite (olive), galena (medium grey); Oktjabrsky, Norilsk, GUS [d]; Nic. // B Insizwaite (medium brown), froodite (darker brown), native silver (medium grey), altaite (dark grey with greenish tint), chalcopyrite (greenish grey), galena (isotropic); Oktjabrsky, Norilsk, GUS [d]; Nic. +

402

Insizwaite A

17 μ

B

17 μ 403

Padmaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins dirty yellow [45] Bireflectance: isotropic, occasionally slight olive to turquoise anisotropy



Descriptions A Massive padmaite (dirty yellow patches) intergrown with stibiopalladinite (cream), bohdanowiczite (?, light pink-brownish tint), sperrylite (white with slight bluish tint), native gold (bright yellow, upper edge of photo), silicates (dark grey); Buraco do Ouro gold mine, Cavalcante, Goiás, Brazil [d]; Nic. // B Padmaite (olive to turquoise anisotropy), stibiopalladinite (dark brownish grey), bohdanowiczite (?, dark brown), sperrylite (dark grey), native gold (dark greenish grey), silicates (greenish to milky and multicolour internal reflections); Buraco do Ouro gold mine, Cavalcante, Goiás, Brazil [d]; Nic. +

404

Padmaite A

24 μ

B

24 μ 405

Cobaltite (Cobaltine) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal deposits, contact metamorphic rocks light pink 52.71 Bireflectance: greenish to bluish very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.18-Cobaltite group, Cobaltite-Ullmannite-Tolovkite series II/D.18-10 Cobaltite CoAsS II/D.18-20 Gersdorffite NiAsS II/D.18-25 Jolliffeite (Ni,Co)AsSe II/D.18-30 Willyamite (Co,Ni)SbS II/D.18-40 Ullmannite NiSbS II/D.18-50 Hollingworthite (Rh,Pt,Pd)AsS II/D.18-60 Irarsite (Ir,Ru,Rh,Pt)AsS II/D.18-70 Platarsite (Pt,Rh,Ru)AsS II/D.18-80 Tolovkite IrSbS

mm2 23 – 2/m 3 23 23 – 2/m 3 – 2/m 3 – 2/m 3 23

Descriptions A Euhedral cobaltite (light pink) in pyrrhotite (tombak brown), altaite (light grey with greenish tint), silicates (dark grey); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. // B Massive cobaltite (pinkish grey) in rammelsbergite (greenish grey); Schneeberg, Saxony, Germany [g]; Nic. // C Cobaltite (lamellar, greenish to bluish anisotropy, many scratches), rammelsbergite (blue and brown anisotropy, twinned); Schneeberg, Saxony, Germany [g]; Nic. +

406

Cobaltite A

60 μ

C

B

250 μ

250 μ

407

Gersdorffite (Amoibite, Dobschauite, Grey Nickel Pyrite, Nickel Glance, Sommarugaite, Stirian)

Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins light grey 45.39 isotropic

Bireflectance:


mm2 23 – 2/m 3 23 23 – 2/m 3 – 2/m 3 – 2/m 3 23

Descriptions A Massive gersdorffite (light grey) intergrown with pyrite (creamish white) and chalcopyrite (here brownish yellow, higher Fe content?); Mitterberg mine, Germany [b]; Nic. // B Massive gersdorffite (light grey) with well-developed cleavage cracks; Heimberg Quarry, Wolfshagen, Germany [a]; Nic. //

408

Gersdorffite A

120 μ

B

10 μ 409

Ullmannite (Antimony Nickel Glance, Nickel Bournonite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy:

hydrothermal Ni veins light grey 45.50 (46.3 arsenia Bireflectance: although normally isotropic, sometimes weakly anisotropic with fine lamellation

Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.18-Cobaltite group, Cobaltite-Ullmannite-Tolovkite series II/D.18-10 Cobaltite CoAsS II/D.18-20 Gersdorffite NiAsS II/D.18-25 Jolliffeite (Ni,Co)AsSe II/D.18-30 Willyamite (Co,Ni)SbS II/D.18-40 Ullmannite NiSbS II/D.18-50 Hollingworthite (Rh,Pt,Pd)AsS II/D.18-60 Irarsite (Ir,Ru,Rh,Pt)AsS II/D.18-70 Platarsite (Pt,Rh,Ru)AsS II/D.18-80 Tolovkite IrSbS

mm2 23 – 2/m 3 23 23 – 2/m 3 – 2/m 3 – 2/m 3 23

Descriptions A Massive ullmanite (light grey), partially replaced by millerite (bright yellow), chalcopyrite (dull yellow), and fahlore (?, greenish grey); Müsen, Westphalia, Germany [b]; Nic. // B Massive ullmanite (light grey, typical rectangular cleavage); Müsen, Westphalia, Germany [a]; Nic. //

410

Ullmannite A

120 μ

B

120 μ 411

Hollingworthite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dunite pipe, platinum deposits of layered ultramafic intrusives light grey 49.48 isotropic

Bireflectance:


mm2 23 – 2/m 3 23 23 – 2/m 3 – 2/m 3 – 2/m 3 23

Descriptions A Pointed grain of hollingworthite (light grey) next to laurite (light grey with bluish tint, slightly darker) in isoferroplatinum matrix (cream-white); Konder Mine, Aldan shield, eastern Siberia, Russia [h]; Nic. // B Hollingworthite (darkest mineral), laurite (slightly lighter than hollingworthite), isoferroplatinum (medium grey); Konder Mine, Aldan shield, eastern Siberia, Russia [h]; Nic. +

412

Hollingworthite A

15 μ

B

15 μ 413

Irarsite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

inclusions in chromite of hortonolite dunite, intergrown with hollingworthite or laurite light grey with blue tint 38.88 isotropic

Bireflectance:


mm2 23 – 2/m 3 23 23 – 2/m 3 – 2/m 3 – 2/m 3 23

Descriptions A Irarsite crystal (light grey) in isoferroplatinum (slight creamish tint); Konder Massif, Aldan Shield, Russia [h]; Nic. // B Irarsite (dark grey), isoferroplatinum (brownish grey); Konder Massif, Aldan Shield, Russia [h]; Nic. +

414

Irarsite A

12 μ

B

12 μ 415

Marcasite (Binarite, Poliopyrite,) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, hydrothermal, secondary bluish white and cream 49.01 - 53.83 Bireflectance: weak very strong, brown, blue, and turquoise bluish white to cream

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.20-Marcasite-Iridarsenite series II/D.20-10 Marcasite II/D.20-20 Ferroselite II/D.20-30 Hastite II/D.20-40 Kullerudite II/D.20-50 Frohbergite II/D.20-60 Mattagamite II/D.20-70 Anduoite II/D.20-80 Omeiite II/D.20-90 Iridarsenite

A B C D E

FeS2 FeSe2 CoSe2 NiSe2 FeTe2 CoTe2 (Ru,Os)As2 (Os,Ru)As2 (Ir,Ru)As2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Radial marcasite aggregate (white) with thin pyrite coating (cream); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Marcasite (brown, lilac, and turquoise anisotropy), pyrite (dark); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + (+2°) Radial marcasite (bluish white and cream pleochroism, bireflectance) partially replaced by pyrite (slightly brighter cream than marcasite); Gräfelhof mine, Austria [b]; Nic. // Radial marcasite (bluish white), carbonate (dark grey); Gräfelhof mine, Austria [b]; Nic. // Marcasite (brown to turquoise), pyrite (isotropic, here dark cream), sphalerite (isotropic), carbonate (bright internal reflections); Gräfelhof mine, Austria [b]; Nic. + (+2°)

416

Marcasite A

120 μ

C

B

250 μ

50 μ

D

E

250 μ

250 μ 417

Ferroselite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

red-bed deposits of the Colorado Plateau type, peripheral to pyrite and U concentrations bluish grey 47.62 - 54.30 Bireflectance: strong, dark blue to lilac weak




Descriptions A Anhedral ferroselite (bluish grey) replacing eskebornite (brownish), clausthalite (light grey), chalcopyrite rim (yellow), carbonate (dark grey); Tilkerode, Germany [g]; Nic. // B Ferroselite (dark blue to violet anisotropy), eskebornite (here various brown shades anisotropy), clausthalite (dark), chalcopyrite (dark), carbonate (greyish to white internal reflections); Tilkerode, Germany [g]; Nic. +

418

Ferroselite A

60 μ

B

60 μ 419

Hastite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins cream brown 48.17 - 54.74 Bireflectance: sometimes strong




Descriptions A Irregular hastite (cream brown, elongated shape at center) in umangite (mottled violet) and clausthalite (light grey); Sanogasta, prov. La Rioja, Argentina [f]; Nic. // B Hastite (dark), umangite (orange red anisotropy), clausthalite (dark grey); Sanogasta, prov. La Rioja, Argentina [f]; Nic. +

420

Hastite A

34 μ

B

34 μ 421

Frohbergite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal light grey with bluish or pinkish tint 51.02 - 53.36 Bireflectance: strong, brownish to reddish extremely weak




Descriptions A Reaction rim of frohbergite (pinkish grey) between chalcopyrite (yellow) and an intergrowth of melonite (very slight pink hue) and tellurobismuthite (white); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. // B Intergrowth of frohbergite (light pinkish grey), calaverite (white), sylvanite (similar to frohbergite, but lamellar twinning, pleochroism), and chalcopyrite (yellow), silicates (dark grey); Sacarîmb (Sãcãrâmb; Szekerembe; Nagyág), Hunedoara Co., Romania [j]; Nic. // C Frohbergite (brownish to reddish anisotropy), calaverite (slight dark grey anisotropy), sylvanite (bluish to dark grey anisotropy), chalcopyrite (dark grey), silicates (bright to brownish internal reflections); Sacarîmb (Sãcãrâmb; Szekerembe; Nagyág), Hunedoara Co., Romania [j]; Nic. +

422

Frohbergite A

40 μ

C

B

83 μ

83 μ

423

Mattagamite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

small telluride zone in Zn-rich stratiform deposit of Archaen volcanics grey 47.75 - 54.14 Bireflectance: vivid blue and orange brown weak




Descriptions A Intergrowth of mattagamite (medium grey), tellurantimony (light pink laths), and altaite (light grey with greenish tint); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. // B Mattagamite (vivid blue and orange brown anisotropy), tellurantimony (pinkish grey anisotropy), and altaite (isotropic, many scratches); Mattagami Lake mines, Galinee, Québec, Canada [a]; Nic. +

424

Mattagamite A

25 μ

B

25 μ 425

Froodite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

concentrates of As- and Pb-Cu-rich ores creamy white 57.13 - 59.87 Bireflectance: light to brownish greys cream to brownish

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.21-Borishanskiite-Urvantsevite series II/D.21-05 Borishanskiite II/D.21-10 Froodite II/D.21-20 Urvantsevite

Pd1+x(As,Pb)2 PdBi2 Pd(Bi,Pb)2

mm2 2/m 4/m 2/m 2/m

Descriptions A Anhedral froodite (cream to brownish pleochroism), native silver (white), altaite (greenish tint), exsolution of insizwaite (?, small elliptical grains, brown), chalcopyrite (olive), magnetite grey); Oktjabrsky, Norilsk, GUS [d]; Nic. // B Froodite (anisotropy with brown shades), native silver (relatively bright patches), altaite (dark with greenish tint), chalcopyrite (dark olive), magnetite isotropic); Oktjabrsky, Norilsk, GUS [d]; Nic. +

426

Froodite A

60 μ

B

60 μ 427

Arsenopyrite (Arsenical Pyrite, Thalheimite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:


high temperature veins, pegmatites, contact metamorphic rocks white, faint yellow tint 50.36 - 51.21 Bireflectance: (51.15 - 53.6 cobaltian) strong, red-violet weak, white with bluish tint to faint reddish yellow

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.22-Arsenopyrite series II/D.22-10 Arsenopyrite II/D.22-20 Glaucodot II/D.22-30 Gudmundite II/D.22-40 Ruarsite II/D.22-50 Osarsite II/D.22-60 Alloclasite

A B

C D

E

FeAsS (Co,Fe)AsS FeSbS RuAsS (Os,Ru)AsS (Co,Fe)AsS

2/m 2/m 2/m 2/m 2/m 2/m 2/m 222

Descriptions Euhedral arsenopyrite (rhombohedral to skeletal, white) in myrmekitic intergrowths of falkmanite (greenish) and galena (light grey); Bayerland mine, Fichtelgebirge, Germany [b]; Nic. // Euhedral arsenopyrite (white) next to large pyrite crystals (slightly yellow) and pyrrhotite (cream with brownish tint), carbonate matrix (dark grey); Morro Velho, Minas Gerais, Brazil [b]; Nic. // Arsenopyrite (orange brown, pleochroitic), pyrite (dark) and pyrrhotite (grey to bluish anisotropy), carbonates (brilliant internal reflections); Morro Velho, Minas Gerais, Brazil [b]; Nic. + “Sand-glass” twinning of arsenopyrite (dark bluish and brownish grey anisotropy), small pyrite crystals (isotropic), quartz (white to multicolour internal reflections); Kilbricken Mine, Quin, Co. Clare, Ireland [a]; Nic. + Arsenopyrite twin (blue and brown anisotropy), pyrrhotite (greenish grey anisotropy), sphalerite (isotropic, brown internal reflections); Bleikvassli Mine, Hemnes, Norway [a]; Nic. +

428

Arsenopyrite A

60 μ

C

B

250 μ

250 μ

D

E

50 μ

52 μ 429

Glaucodot Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

deep-seated high-temperature deposits white 50.65 - 50.96 Bireflectance: distinct (less than arsenopyrite), blue to brownish grey slightly yellow



2/m 2/m 2/m 2/m 2/m 2/m 2/m 222

Descriptions A Euhedral glaucodot (white), skutterudite (white, massive), carbonate (dark grey); Christopher Claim, Cobalt, Ontario, Canada [j]; Nic. // B Glaucodot (blue to brownish grey anisotropy, similar to arsenopyrite, but less pronounced), carbonate (white internal reflections); Christopher Claim, Cobalt, Ontario, Canada [j]; Nic. +

430

Glaucodot A

60 μ

B

60 μ 431

Gudmundite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late mineral in hydrothermal sulfide deposits silver-white to steel-grey 50.94 - 54.87 Bireflectance: slight pronounced blue, orange-brown, and red distinct, in pure white and pinkish white



2/m 2/m 2/m 2/m 2/m 2/m 2/m 222

Descriptions A Euhedral gudmundite (white), pyrrhotite (light brown), pyrite (cream), galena (light grey), sphalerite (medium grey), carbonate (dark grey); South Broken Hill, New South Wales, Australia [j]; Nic. // B Subhedral gudmundite twins (white) with chalcopyrite rim (yellow), small sphalerite grains (darker grey) enclosed in chalcopyrite, tetrahedrite matrix (olive tinted medium grey); Seinäjoki, Österbottn, Finland [j]; Nic. // C Gudmundite (pronounced blue, brown, and red anisotropy), chalcopyrite (mottled blue to dark olive anisotropy), sphalerite (isotropic), tetrahedrite (isotropic); Seinäjoki, Österbottn, Finland [j]; Nic. +

432

Gudmundite A

100 μ

C

B

45 μ

45 μ

433

Löllingite

(Arsenoferrite, Arsenosiderite, Glaukopyrite, Hoffmannite, Hüttenbergite, Leukopyrite, Mohsine, Pharmakopyrite, Sätersbergite)


mesothermal hydrothermal deposits, pegmatites cream to bluish white 54.25 - 51.43 Bireflectance: strong, orange, brown, and blue cream to bluish white

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.23-Löllingite-Costibite series II/D.23-10 Löllingite II/D.23-20 Safflorite II/D.23-30 Rammelsbergite II/D.23-40 Seinajokite II/D.23-50 Nisbite II/D.23-60 Costibite II/D.23-70 Oenite

FeAs2 (Co,Fe)As2 NiAs2 (Fe,Ni)(Sb,As)2 NiSb2 CoSbS CoSbAs

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m mm2 ortho.

Descriptions A Large subhedral löllingite (cream to bluish white, bireflectance); unknown locality [a]; Nic. // B Löllingite (strong orange, brown, and blue anisotropy); unknown locality [a]; Nic. + C Löllingite (strong orange, brown, and blue anisotropy) with arsenopyrite (?) inclusions (lower anisotropy); Reichenstein, Silesia, Poland [a]; Nic. +

434

Löllingite A

120 μ

C

B

250 μ

250 μ

435

Safflorite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature and -pressure hydrothermal veins yellowish to bluish white 52.02 - 54.46 Bireflectance: strong, dark brown to blue weak, yellowish to bluish white

minimal


A B C D E



Descriptions Euhedral safflorite (yellowish to bluish white, minimal bireflectance); Chalongos, Allemont, Dauphiné, France [e]; Nic. // Safflorite (brown to blue anisotropy); Chalongos, Allemont, Dauphiné, France [e]; Nic. + Safflorite (dark brown to blue), skeletal bismuth crystal (strongly scratched), quartz (bright internal reflections); Schneeberg, Germany [b]; Nic. + Safflorite twins (light grey) in carbonate matrix (dark grey, bireflectance); Christopher Claim, Cobalt, Ontario, Canada [j]; Nic. // Safflorite (brown to blue anisotropy), carbonate (white internal reflections); Christopher Claim, Cobalt, Ontario, Canada [j]; Nic. +

436

Safflorite A

120 μ

C

B

250 μ

78 μ

D

E

47 μ

47 μ 437

Rammelsbergite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal Ni-Co veins pure white 55.80 - 57.80 Bireflectance: strong, dark brown to blue weak, yellow to pinkish and bluish white


A B

C D E



Descriptions Rammelsbergite layer (white) on nickeline (light orange), proustite (greenish grey), chalcopyrite (yellow); Medenec (Kupferberg), Ústí Region, Czech Republic [a]; Nic. // Rammelsbergite (blue to brownish grey anisotropy), nickeline (turquoise to orange brown anisotropy), proustite (dark greenish grey anisotropy, faint red internal reflections), chalcopyrite (dark olive grey); Medenec (Kupferberg), Ústí Region, Czech Republic [a]; Nic. + Anhedral rammelsbergite (white with cracks); Zinkwand-Vöttern, Austria [b]; Nic. // Rammelsbergite (dark brown to blue anisotropy); Zinkwand-Vöttern, Austria [b]; Nic. + Rammelsbergite (orange-brown to blue anisotropy); Zinkwand-Vöttern, Austria [b]; Nic. + (+ 2°)

438

Rammelsbergite A

60 μ

C

B

125 μ

250 μ

D

E

250 μ

250 μ 439

Pararammelsbergite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Ni-Co veins white 58.11 - 60.05 Bireflectance: strong, dark brownish to bluish

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.24-Clinosafflorite-Paracostibite series II/D.24-10 Clinosafflorite II/D.24-20 Pararammelsbergite II/D.24-30 Paracostibite

(Co,Fe,Ni)As2 NiAs2 CoSbS

2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Pararammelsbergite (white), partially replaced by nickeline (light orange), carbonate (dark grey); Zinkwand-Vättern, Schladming, Austria [j]; Nic. // B Anhedral pararammelsbergite (white), some nickeline (orange), calcite (dark); Zinkwand-Vättern, Schladming, Austria [b]; Nic. // C Pararammelsbergite (brown to blue anisotropy), nickeline (similar anisotropy), calcite (bright internal reflections); Zinkwand-Vättern, Schladming, Austria [b]; Nic. + (+2°)

440

Pararammelsbergite A

60 μ

C

B

125 μ

125 μ

441

Molybdenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins, porphyry type deposits bright to medium grey 20.51 - 44.27 Bireflectance: strong very strong, light to dark grey shades very strong

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.25-Molybdenite series II/D.25-05 Rheniite II/D.25-10 Molybdenite II/D.25-20 Jordisite II/D.25-30 Drysdallite II/D.25-40 Tungstenite

A B C D

E

ReS2 MoS2 MoS2 Mo(Se,S)2 WS2

hex. 6/m 2/m 2/m none 6/m 2/m 2/m 6/m 2/m 2/m

Descriptions Deformed molybdenite platelets (bright to medium grey, strong bireflectance, pressure twinning), pyrrhotite (pinkish grey); Mittersill, Austria [b]; Nic. // Molybdenite (silvery grey shades), pyrrhotite (dark); Mittersill, Austria [b]; Nic. + Radial molybdenite (strong grey bireflectance), vaesite (tinted medium grey), silicate (dark grey); Shinkolobwe Mine, Shaba, Congo [j]; Nic. // Molybdenite as basal (hexagonal, white) and longitudinal cut (darker grey, cleavage, bireflectance), aikinite (yellowish tint), quartz (dark grey); Zinngrube, Altenberg, Saxony, Germany [a]; Nic. // Molybdenite as basal (hexagonal, dark, almost isotropic) and longitudinal cut (various grey shades anisotropy, cleavage), aikinite (blue and brown anisotropy), quartz (milky multicoloured internal reflections); Zinngrube, Altenberg, Saxony, Germany [a]; Nic. +

442

Molybdenite A

60 μ

C

B

125 μ

32 μ

D

E

66 μ

66 μ 443

Jordisite (amorphous MoS2) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate- to low-temperature hydrothermal veinlets greenish tinted grey 20.50 - 44.20

Bireflectance:




Descriptions A Irregular patch of jordisite (greenish tinted grey), partially recrystallised to molybdenite (lighter grey shades anisotropy), galena (lightest grey), quartz (dark grey); Mezica (Miess), Slovenia [j] ; Nic. // B Jordisite (dark), molybdenite (silvery grey anisotropy), galena (isotropic), quartz (milky internal reflections); Mezica (Miess), Slovenia [j] ; Nic. +

444

Jordisite A

24 μ

B

24 μ 445

Tungstenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dolomite replaced by Zn-Pb-Cu-Fe sulfides with accessory Ga, Ge, Mo, W, and V light to bluish grey 17.80 - 34.96 Bireflectance: strong strong, silver-white, dark, pink, deep blue strong, light to bluish grey


A

B C

D E



Descriptions Mass of tungstenite platelets (bluish grey, strong bireflectance) and graphite (dirty yellowish brown, strong bireflectance) in bornite matrix (pinkish brown); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. // Tungstenite (strong white to dark bluish grey anisotropy), graphite (strong cream to dark anisotropy), bornite (dark); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. + Radial tungstenite (strong light to dark grey bireflectance) with rim of betekhtinite (cream) and tennantite (greenish grey), bornite (pinkish brown); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. // Tungstenite (strong silver-white, dark, pink, and deep blue anisotropy), betekhtinite (here very dark olive anisotropy), bornite (dark); Kipushi Mine, Lubumbashi, Shaba, Congo [j]; Nic. + Tungstenite (light grey bireflectance) enveloping scheelite grains (medium grey); Magnesite mine, Tux valley, Ziller valley,Tyrol, Austria [j]; Nic. //

446

Tungstenite A

24 μ

C

B

33 μ

138 μ

D

E

110 μ

46 μ 447

Berndtite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high temperature alteration product of hydrothermal Sn sulfide veins dark grey with orange tint bright orange [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.28-Melonite group, Berntdtite-Moncheite series II/D.28-10 Berndtite SnS2 II/D.28-20 Kitkaite NiTeSe II/D.28-30 Melonite NiTe2 II/D.28-35 Sudovikovite PtSe2 II/D.28-40 Merenskyite (Pd,Pt)(Te,Bi)2 II/D.28-45 Shuangfengite IrTe2 II/D.28-50 Moncheite (Pt,Pd)(Te,Bi)2 II/D.28-60 Verbeekite PdSe2

– 3 2/m – 3 2/m – 3 2/m – 3 2/m 3m – 3 2/m – 3 2/m mono.

Descriptions A Radial berndtite (dark grey, but with brown internal reflections shining through) replacing ottemannite (slightly lighter fibres around it), herzenbergite (light grey fibres), cassiterite (medium greys), quartz (dark grey); Maria Theresia mine, Huari, Bolivia [g]; Nic. // B Berndtite (bright orange internal reflections), ottemannite (dark), herzenbergite (dark), cassiterite (colourless internal reflections), quartz (multicolour internal reflections); Maria Theresia mine, Huari, Bolivia [g]; Nic. +

448

Berndtite A

60 μ

B

60 μ 449

Melonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late stage of moderate- to low-temperature hydrothermal veins, hightemperature magmatic sulfide deposits slight pink tint 62.45 - 60.60 Bireflectance: weak, brown shades moderate to strong


– 3 2/m – 3 2/m – 3 2/m – 3 2/m 3m – 3 2/m – 3 2/m mono.

Descriptions A Prismatic melonite (slight pinkish grey) intergrown with altaite (white), silicates (dark); RobbMontbray Mine, Montbray Township, Québec, Canada [j]; Nic. // B Melonite crystal (white) in bornite (pinkish brown), quartz (dark grey); Spectacle Mine, Okiep, Namaqualand, Northern Cape Province, South Africa [j]; Nic. // C Melonite (various brown shades anisotropy), tellurobismuthite (blue grey anisotropy), chalcopyrite (yellow); Robb-Montbray Mine, Montbray Township, Abitibi Co., Québec, Canada [j]; Nic. +

450

Melonite A

60 μ

C

B

66 μ

125 μ

451

Moncheite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

layered intrusions with PGE-Cu-Ni light grey 56.88 - 57.78 Bireflectance: strong, except in basal sections weak


– 3 2/m – 3 2/m – 3 2/m – 3 2/m 3m – 3 2/m – 3 2/m mono.

Descriptions A Anhedral moncheite (light grey, upper right extension of main ore grain) next to chalcopyrite (yellow), pyrrhotite (brownish grey) with mackinawite lamella (yellowish); Hartley Mine, Zimbabwe [d]; Nic. // B Moncheite (darkest ore grain, anisotropy grades to black), chalcopyrite (dark bluish grey), pyrrhotite (dark brown grey), mackinawite (similar to chalcopyrite); Hartley Mine, Zimbabwe [d]; Nic. +

452

Moncheite A

6μ

B

6μ 453

Skutterudite (Modumite, Smaltite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal Ni-Co veins cream-white 53.56 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.29-Skutterudite-Iridisite series II/D.29-10 Skutterudite II/D.29-20 Nickel-skutterudite II/D.29-25 Kieftite II/D.29-30 Iridisite II/D.29-40 Gaotaiite

A B

C D E

(Co,Ni)As3-x (Ni,Co)As3-x CoSb3 (Ir,Cu,Rh,Ni,Pt)S2 Ir3Te8

– 2/m 3 – 2/m 3 – 2/m 3 cub. – 2/m 3

Descriptions Coarse skutterudite (white) around bismuth (pinkish white), fine-grained safflorite aggregates (colour similar to skutterudite, “saw-tooth“-crystals); Schneeberg, Germany [b]; Nic. // Skeletal skutterudite (white) intergrown with chalcopyrite (yellow) and tennantite (greenish grey), quartz (dark grey); Straßburger Glück Mine, Oberwiesenthal, Erzgebirge, Germany [a]; Nic. // Fe-Skutterudite (Cathamite; white) rim around skutterudite (slightly brighter white); Vater Abraham mine, Marienberg, Erzgebirge, Germany [b]; Nic. // Zoned skutterudite aggregates (light creamish), fluorite (dark grey); Vater Abraham Mine, Morgengang, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. // Euhedral skutterudite aggregate (very light grey, irregular cracks) with core of nickeline (slight orange pleochroism), pyrrhotite (unusual, almost olive grey colour), goethite (dark grey); Core Drilling near Orahovac, Kosovo, Serbia [j]; Nic. //

454

Skutterudite A

120 μ

C

B

156 μ

287 μ

D

E

117 μ

161 μ 455

Nickel-Skutterudite (Chloanthite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy:

moderate-temperature hydrothermal veins yellowish grey 56.56 Bireflectance: although generally isotropic, sometimes weak to occasionally distinctly anisotropic

Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography II/D.29-Skutterudite-Iridisite series II/D.29-10 Skutterudite II/D.29-20 Nickel-skutterudite II/D.29-25 Kieftite II/D.29-30 Iridisite II/D.29-40 Gaotaiite

(Co,Ni)As3-x (Ni,Co)As3-x CoSb3 (Ir,Cu,Rh,Ni,Pt)S2 Ir3Te8

– 2/m 3 – 2/m 3 – 2/m 3 cub. – 2/m 3

Descriptions A Layers of subhedral nickel-skutterudite (slightly yellowish grey) intergrown with skutterudite (slightly darker grey) in matrix of native bismuth (pinkish tint, many scratches); Ludwig-Vereinigt-Feld Mine, Oelsnitz, Saxony, Germany [a]; Nic. // B Nickel-skutterudite (isotropic, marginally brighter than skutterudite), skutterudite (isotropic), native bismuth (here brownish grey anisotropy, many scratches); Ludwig-Vereinigt-Feld Mine, Oelsnitz, Saxony, Germany [a]; Nic. + C Massive nickel-skutterudite (almost white, cataclastic fractures), carbonate (dark grey); Daniel Mine, Schneeberg, Saxony, Germany [a]; Nic. //

456

Nickel-Skutterudite A

60 μ

C

B

125 μ

250 μ

457

Berthierite (Anglarite, Chazellite, Martourite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal Sb veins pinkish grey 31.59 - 39.62 Bireflectance: strong marked, tinted greys

here distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.01-Berthierite-Garavellite series II/E.01-05 Clerite II/E.01-10 Berthierite II/E.01-20 Garavellite

A B C D E

MnSb2S4 FeSb2S4 FeSbBiS4

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Anhedral berthierite (pinkish grey, bireflectance) in stibnite matrix (light and darker grey, bireflectance); Indarama, Zimbabwe [g]; Nic. // The same berthierite (rotated polariser; pinkish grey, bireflectance), stibnite (almost the same grey shade, bireflectance); Indarama, Zimbabwe [g]; Nic. // Berthierite (greenish/bluish and dark grey, anisotropy), stibnite (darkest position of anisotropy); Indarama, Zimbabwe [g]; Nic. + Euhedral to subhedral berthierite (light to pinkish grey, bireflectance), quartz matrix (dark grey); Kutna Hora, Czech Republic [a]; Nic. // Berthierite (greenish/bluish to dark grey, anisotropy), quartz (milky internal reflections); Kutna Hora, Czech Republic [a]; Nic. //

458

Berthierite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 459

Wittichenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Bi-carrying hydrothermal veins cream-grey 33.37 - 35.26 Bireflectance: weak, dark brownish grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.03-Skinnerite-Wittichenite series II/E.03-10 Skinnerite II/E.03-20 Wittichenite

Cu3SbS3 Cu3BiS3

2/m 222

Descriptions A Myrmekitic wittichenite (light cream-grey) intergrown with fahlore (greenish grey); Cuadro Juan, Cosuno, Bolivia [d]; Nic. // B Anhedral wittichenite (cream), covellite (blue, pronounced cleavage), specs of native bismuth (white); Wittichen, Black Forest, Germany [a]; Nic. // C Exsolution (?) of wittichenite (cream-grey) in bornite (orange brown), covellite (blue, bireflectance) partially replaces wittichenite; Avila, Salamanca, Spain [j]; Nic. //

460

Wittichenite A

19 μ

C

B

29 μ

73 μ

461

Chalcostibite (Guejarite, Rosite, Wolfsbergite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins bluish grey 35.18 - 40.46 Bireflectance: bluish to brownish grey very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.04-Chalcostibite-Hodrushite series II/E.04-10 Chalcostibite II/E.04-20 Emplectite II/E.04-25 Kupcikite II/E.04-30 Cuprobismutite II/E.04-40 Hodrushite

A B C D E

CuSbS2 CuBiS2 Cu3.4Fe0.6Bi5S10 Cu10Bi12S23 Cu8Bi12S22

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Chalcostibite needles (bluish to brown anisotropy), carbonate (bright internal reflections); Römerstollen, Abfaltersbach, Linz, Austria [a]; Nic. + Aggregate of elongated chalcostibite grains (light bluish grey) in carbonate (dark grey); Römerstollen, Abfaltersbach, Linz, Austria [a]; Nic. // Chalcostibite grains (bluish to brown anisotropy), carbonate (bright internal reflections); Römerstollen, Abfaltersbach, Linz, Austria [a]; Nic. + Anhedral chalcostibite (bluish grey) on pyrite (cream-white); Mariengrube, Nikolsdorf, Austria [b]; Nic. // Chalcostibite (blue grey to dark), pyrite (here olive brown); Mariengrube, Nikolsdorf, Austria [b]; Nic. +

462

Chalcostibite A

60 μ

C

B

50 μ

50 μ

D

E

125 μ

125 μ 463

Emplectite (Hemichalcite, Tannenite, Termanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins yellowish grey 37.23 - 38.44 Bireflectance: turquoise tinted grey to dark brown very low

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.04-Chalcostibite-Hodrushite series II/E.04-10 Chalcostibite II/E.04-20 Emplectite II/E.04-25 Kupcikite II/E.04-30 Cuprobismutite II/E.04-40 Hodrushite

CuSbS2 CuBiS2 Cu3.4Fe0.6Bi5S10 Cu10Bi12S23 Cu8Bi12S22

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Replacement of emplectite (yellowish grey) by chalcopyrite (olive) and native bismuth (white); Daniel-Gang, Wittichen, Germany [e]; Nic. // B Irregular intergrowth of emplectite (yellowish grey) with wittichenite (medium grey), chalcopyrite (olive), native bismuth (white); Daniel-Gang, Wittichen, Germany [e]; Nic. // C Emplectite (turquoise tinted grey), wittichenite (dark brown grey), chalcopyrite (similar to emplectite); Daniel-Gang, Wittichen, Germany [e]; Nic. +

464

Emplectite A

47 μ

C

B

125 μ

125 μ

465

Polybasite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal Ag veins brownish tint specs, red 30.02 - 31.43 Bireflectance: dark greenish to bluish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.05-Billingsleyite-Polybasite series II/E.05-10 Billingsleyite II/E.05-20 Pearceite II/E.05-30 Antimonpearceite II/E.05-40 Arsenpolybasite II/E.05-50 Polybasite

Ag7AsS6 Ag16As2S11 (Ag,Cu)16(Sb,As)2S11 (Ag,Cu)16(As,Sb)2S11 (Ag,Cu)16Sb2S11

222 2/m 2/m 2/m 2/m

Descriptions A Euhedral polybasite (brownish tint, laths), miargyrite (grey with blue tint), chalcopyrite (yellow), carbonate (dark grey); Brand-Erbisdorf, Saxony, Germany [g]; Nic. // B Polybasite (dark bluish grey anisotropy), miargyrite (blue grey to dark anisotropy), chalcopyrite (dark), carbonate (white internal reflections); Brand-Erbisdorf, Saxony, Germany [g]; Nic. + C Polybasite (dark, fine red internal reflections along scratches), miargyrite (dark greenish grey anisotropy); Brand-Erbisdorf, Saxony, Germany [g]; Nic. +

466

Polybasite A

60 μ

C

B

125 μ

24 μ

467

Stephanite (Brittle Silver Ore, Melakonite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late-stage mineral of hydrothermal Ag deposits medium grey 26.37 - 28.06 Bireflectance: strong, brownish greys very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.06-Stefanite-Arcubisite series II/E.06-10 Stephanite II/E.06-20 Selenostephanite II/E.06-30 Arcubisite II/E.06-40 Fettelite

Ag5SbS4 Ag5Sb(Se,S)4 Ag6CuBiS4 Ag24HgAs5S20

mm2 222 ortho. trig.

Descriptions A Massive stephanite (medium grey, scratches); Freiberg, Saxony, Germany [e]; Nic. // B Stephanite (different shades of brownish grey anisotropy); Freiberg, Saxony, Germany [e]; Nic. + C Stephanite (different shades of beige grey anisotropy); Freiberg, Saxony, Germany [e]; Nic. + (+2°)

468

Stephanite A

120 μ

C

B

250 μ

250 μ

469

Proustite (Light Red Silver Ore, Ruby Silver Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy:

late mineral in hydrothermal Ag-rich deposits, enrichment zone medium grey with bluish to pinkish hue strong, red 27.89 - 29.99 Bireflectance: occasionally strong, dark to greenish grey, anisotropy often masked by strong internal reflections

Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.07-Proustite-Samsonite series II/E.07-10 Proustite II/E.07-20 Pyrargyrite II/E.07-30 Xanthoconite II/E.07-40 Pyrostilpnite II/E.07-50 Samsonite II/E.07-60 Quadratite

Ag3AsS3 Ag3SbS3 Ag3AsS3 Ag3SbS3 Ag4MnSb2S6 Ag(Cd,Pb)AsS3

– 3 2/m 3m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Anhedral proustite (medium grey), euhedral arsenopyrite (white), marcasite (cream); Freiberg, Saxony, Germany [e]; Nic. // B Massive proustite (bright red internal reflections, polysynthetic twins, strong dark to greenish grey anisotropy), stephanite (here dark); Freiberg, Saxony, Germany [a]; Nic. +

470

Proustite A

120 μ

B

60 μ 471

Pyrargyrite (Dark Red Silver Ore, Ruby Red Silver Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late-stage low-temperature hydrothermal, secondary enrichment blue-greys strong, red 26.04 - 31.34 Bireflectance: relatively strong strong, light and dark blue-grey, anisotropy masked by strong internal reflections blue-greys

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.07-Proustite-Samsonite series II/E.07-10 Proustite II/E.07-20 Pyrargyrite II/E.07-30 Xanthoconite II/E.07-40 Pyrostilpnite II/E.07-50 Samsonite II/E.07-60 Quadratite

A B C D E


– 3 2/m 3m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions Euhedral pyrargyrite (bluish greys, bireflectance), aikinite (light cream, upper right), safflorite (white, lower left); Beresowsk, Russia [e]; Nic. // Pyrargyrite (blue to grey anisotropy, red internal reflections), aikinite (medium grey); Beresowsk, Russia [e]; Nic. + Pyrargyrite (red internal reflections), sphalerite (isotropic, some red brown internal reflections), galena (isotropic); Portugalete, Potosí Department, Bolivia [a]; Nic. + Euhedral pyrargyrite (bluish grey), safflorite (white); Beresowsk, Russia [e]; Nic. // Anhedral pyrargyrite on cracks (blue-grey), breithauptite (slight pink to violet bireflectance) intergrown with nickeline (orange), small euhedral pyrite (slightly bluish cream); Cobalt, Ontario, Canada [a]; Nic. //

472

Pyrargyrite A

60 μ

C

B

58 μ

72 μ

D

E

82 μ

78 μ 473

Xanthoconite (Rittingerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins with other Ag sulfosalts bluish grey red-brown to lemon yellow 21.78 - 25.19 Bireflectance: distinct, greyish, often masked by strong internal reflections



– 3 2/m 3m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Euhedral xanthoconite (bluish grey) on native arsenic (cream); Vater Abraham Mine, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. // B Xanthoconite (strong red-brown internal reflections), native arsenic (slight dark bluish and brownish grey anisotropy); Vater Abraham Mine, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. + C Xanthoconite (strong red-brown internal reflections, distinct greyish anisotropy), native arsenic (almost dark, slight anisotropy); Vater Abraham Mine, Lauta, Marienberg, Erzgebirge, Saxony, Germany [j]; Nic. +

474

Xanthoconite A

40 μ

C

B

83 μ

208 μ

475

Samsonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Ag vein deposits medium bluish grey dark red 27.15 - 27.80 Bireflectance: dark greenish or bluish to brownish



– 3 2/m 3m 2/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Fragment of a large samsonite crystal (medium grey, brittle conchoidal fracture); Samson Mine, St. Andreasberg, Hartz Mts., Germany [j]; Nic. // B Samsonite (dark, strong red internal reflections along fractures); Samson Mine, St. Andreasberg, Hartz Mts., Germany [j]; Nic. + C Samsonite (dark greenish to brownish anisotropy, faint red internal reflections); Samson Mine, St. Andreasberg, Hartz Mts., Germany [j]; Nic. +

476

Samsonite A

60 μ

C

B

125 μ

125 μ

477

Hutchinsonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal grey with bluish tint orange to red [25] Bireflectance: strong, bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.13-Livingstonite-Vaughanite series II/E.13-10 Livingstonite II/E.13-20 Grumiplucite II/E.13-30 Simonite II/E.13-40 Vrbaite II/E.13-42 Edenharterite II/E.13-43 Jentschite II/E.13-45 Hutchinsonite II/E.13-50 Lorandite II/E.13-60 Weissbergite II/E.13-70 Tvalchrelidzeite II/E.13-80 Vaughanite

HgSb4S8 HgBi2S4 TlHgAs3S6 Tl4Hg3Sb2As8S20 TlPbAs3S6 TlPbAs2SbS6 (Pb,Tl)2As5S9 TlAsS2 TlSbS2 Hg12(Sb,As)8S15 TlHgSb4S7

2/m 2/m 2/m 2/m 2/m 2/m mm2 2/m 2/m 2/m 2/m 2/m 1 1 1

Descriptions A Radial aggregate of hutchinsonite (grey with bluish tint) in schalenblende (sphalerite, medium grey), jordanite layer (lightest grey); Wiesloch, Baden, Germany [g]; Nic. // B Hutchinsonite (red internal reflections, bluish anisotropy), sphalerite (dark brown internal reflections), jordanite layer (bluish to grey anisotropy); Wiesloch, Baden, Germany [g]; Nic. +

478

Hutchinsonite A

60 μ

B

60 μ 479

Lorandite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal medium grey bright orange 25.44 - 27.25 Bireflectance: difficult to see, purple-red, orange-red

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.13-Livingstonite-Vaughanite series II/E.13-10 Livingstonite II/E.13-20 Grumiplucite II/E.13-30 Simonite II/E.13-40 Vrbaite II/E.13-42 Edenharterite II/E.13-43 Jentschite II/E.13-45 Hutchinsonite II/E.13-50 Lorandite II/E.13-60 Weissbergite II/E.13-70 Tvalchrelidzeite II/E.13-80 Vaughanite

HgSb4S8 HgBi2S4 TlHgAs3S6 Tl4Hg3Sb2As8S20 TlPbAs3S6 TlPbAs2SbS6 (Pb,Tl)2As5S9 TlAsS2 TlSbS2 Hg12(Sb,As)8S15 TlHgSb4S7

2/m 2/m 2/m 2/m 2/m 2/m mm2 2/m 2/m 2/m 2/m 2/m 1 1 1

Descriptions A Anhedral lorandite (medium grey with orange tint from internal reflections), stibnite (light grey), fine pyrite (cream), pyrite (dark grey); Allchar (Alsar), Roszdan, Macedonia [j]; Nic. // B Lorandite (bright orange internal reflections), stibnite (bluish grey anisotropy), fine pyrite (isotropic), quartz (milky internal reflections); Allchar (Alsar), Roszdan, Macedonia [j]; Nic. +

480

Lorandite A

40 μ

B

40 μ 481

Jordanite (Reniforite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Pb-As occurrences in dolomite grey 37.82 - 40.88 Bireflectance: brownish grey to blue

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.15-Jordanite-Lengenbachite series II/E.15-10 Jordanite II/E.15-20 Geocronite II/E.15-30 Gratonite II/E.15-40 Meneghinite II/E.15-45 Tsugaruite II/E.15-50 Lengenbachite

Pb14(As,Sb)6S23 Pb14(Sb,As)6S23 Pb9As4S15 Pb13CuSb7S24 Pb4As2S7 Pb6(Ag,Cu)2As4S13

2/m 2/m 3m 2/m 2/m 2/m ortho. tri.

Descriptions A Radial fibres of jordanite (light grey) in a matrix of “schalenblende” (laminar sphalerite; medium grey); Wiesloch, Baden, Germany [b]; Nic. // B Jordanite (strong anisotropy between brownish grey and blue), sphalerite (cream to white internal reflections); Wiesloch, Baden, Germany [b]; Nic. + C Jordanite (brown to blue anisotropy) fully replaced gratonite, sphalerite (red to yellow internal reflections); Wiesloch, Baden, Germany [g]; Nic. +

482

Jordanite A

239 μ

C

B

500 μ

125 μ

483

Geocronite (Kilbrickenite, Schulzite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins light grey 37.97 - 39.17 Bireflectance: moderate, bluish to olive grey weak

faint




Descriptions A Massive geocronite (light grey), along cracks it is replaced by galena (slightly brighter grey) and boulangerite (slightly darker, grey with greenish tint); Bayerland Mine, Mitterteich, Bavaria, Germany [j]; Nic. // B Massive geocronite (light grey, faint bireflectance); Bayerland Mine, Mitterteich, Bavaria, Germany [j]; Nic. // C Geocronite (bluish to olive to grey and undulating anisotropy), mainly coarse twinning crosscut by fine polysynthetic twins; Bayerland Mine, Mitterteich, Bavaria, Germany [j]; Nic. +

484

Geocronite A

95 μ

C

B

250 μ

250 μ

485

Gratonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu ores medium grey, distinctly yellow against galena 33.96 - 34.5 Bireflectance: brown to bluish grey very weak




Descriptions A Euhedral gratonite (light grey) in “schalenblende” (sphalerite; medium grey); Wiesloch, Baden, Germany [g]; Nic. // B Euhedral gratonite (light grey) in “schalenblende” (sphalerite; medium grey); Wiesloch, Baden, Germany [g]; Nic. // C Gratonite (brown to bluish grey, difficult to discern under microscope), sphalerite (dark); medium grey); Wiesloch, Baden, Germany [g]; Nic. +

486

Gratonite A

55 μ

C

B

250 μ

250 μ

487

Meneghinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, contact metamorphic light brownish grey shades 39.37 - 44.83 Bireflectance: weak distinct, brownish grey shades

distinct




Descriptions A Coarse radial meneghinite (light brownish grey shades, bireflectance); Pun-dung, North Korea [j]; Nic. // B Meneghinite (light to dark brownish grey anisotropy, slight ductility visible in undulating shades); Pun-dung, North Korea [j]; Nic. +

488

Meneghinite A

120 μ

B

120 μ 489

Seligmannite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-grade/-temperature metamorphic Pb, Zn, As, Tl, Ba ores medium pinkish grey 31.51 - 32.92 Bireflectance: strong, brownish grey to dark

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.16-Seligmannite-Bournonite series II/E.16-10 Seligmannite II/E.16-20 Bournonite

PbCuAsS3 PbCuSbS3

2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Anhedral seligmannite (slightly pinkish grey) intergrown with in tennantite (greenish grey), pyrite (cream); Cerro de Pasco, Peru [e]; Nic. // B Seligmannite (brownish grey to dark anisotropy), tennantite (isotropic, small red internal reflections), pyrite (isotropic); Cerro de Pasco, Peru [e]; Nic. +

490

Seligmannite A

60 μ

B

60 μ 491

Bournonite (Berthonite, Endellionite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins brownish grey 33.33 - 35.23 Bireflectance: weak in air very weak, blue grey to brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.16-Seligmannite-Bournonite series II/E.16-10 Seligmannite II/E.16-20 Bournonite

A B C D E

PbCuAsS3 PbCuSbS3

2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Bournonite (light greenish grey), pyrite (cream), galena (light grey), schwazite (greenish grey), chalcopyrite (dull yellow); Kotterbach, Slovak Republic [d]; Nic. // Anhedral bournonite (grey with brownish tint) intergrown with boulangerite (slightly brighter and bluish tint, partially prismatic); Oberlahr, Westerwald, Germany [a]; Nic. // Bournonite (grey brown), boulangerite (blue grey to grey anisotropy); Oberlahr, Westerwald, Germany [a]; Nic. + Twinned bournonite (olive grey and dark anisotropy), 2 small euhedral pyrite crystals (slightly brighter tinted grey; center and left edge); Kotterbach, Slovak Republic [d]; Nic. + Twinned bournonite (light olive grey and bluish grey anisotropy), 2 small euhedral pyrite crystals (tinted grey; center and left edge); Kotterbach, Slovak Republic [d]; Nic. + (+2°)

492

Bournonite A

60 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 493

Freieslebenite (Delislite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins medium to light grey 36.02 - 41.22 Bireflectance: minimal difficult to observe, dark and medium grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.17-Marrite-Owyheeite series II/E.17-10 Marrite II/E.17-20 Freieslebenite II/E.17-30 Diaphorite II/E.17-40 Zoubekite II/E.17-50 Owyheeite

PbAgAsS3 AgPbSbS3 Pb2Ag3Sb3S8 AgPb4Sb4S10 Pb7Ag2(Sb,Bi)8S20

2/m 2/m 2/m ortho. 2/m 2/m 2/m

Descriptions A Freieslebenite (lighter grey) with oriented intergrowth of chalcopyrite (yellow); Braunsdorf, Freiberg, Germany [e]; Nic. // B Anhedral freieslebenite (lighter greys, minimal bireflectance) with laminar alteration rim of malachite (darker grey); Braunsdorf, Freiberg, Germany [e]; Nic. // C Freieslebenite (dark and medium grey anisotropy), malachite (green); Braunsdorf, Freiberg, Germany [e]; Nic. +

494

Freieslebenite A

239 μ

C

B

250 μ

250 μ

495

Diaphorite (Brongniardite - see also Argyrodite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins creamish grey 36.37 - 39.67 Bireflectance: distinct, brownish to bluish grey


A

B

C

D

E


2/m 2/m 2/m ortho. 2/m 2/m 2/m

Descriptions Massive diaphorite (creamish grey) with alteration to pyrargyrite (bluish grey, euhedral) and fibrous mineral (jamesonite?, yellowish tint, fine-grained); Himmelsfürst Mine, Brand-Erbisdorf, Erzgebirge, Saxony, Germany [j]; Nic. // Diaphorite (creamish grey), along edge alteration to pyrargyrite (bluish grey, euhedral) and a fibrous mineral (jamesonite?, yellowish tint, fine-grained), silicate (dark grey); Himmelsfürst Mine, Brand-Erbisdorf, Erzgebirge, Saxony, Germany [j]; Nic. // Diaphorite (dark brownish grey), pyrargyrite (bright red internal reflections), jamesonite (?, anisotropy with slight blue tint), silicate (white internal reflections); Himmelsfürst Mine, Brand-Erbisdorf, Erzgebirge, Saxony, Germany [j]; Nic. + Anhedral diaphorite (cream-grey), pyrargyrite (bluish grey), euhedral arsenopyrite (yellowish tint), sphalerite (medium grey), silicates (dark grey); Tullock Mine, Rockvale, New South Wales, Australia [j]; Nic. // Diaphorite (twin lamellae, brownish to bluish grey anisotropy), pyrargyrite (red internal reflections), arsenopyrite (brownish anisotropy), sphalerite (isotropic, some brown internal reflections), silicates (translucent); Tullock Mine, Rockvale, New South Wales, Australia [j]; Nic. +

496

Diaphorite A

60 μ

C

B

50 μ

50 μ

D

E

67 μ

67 μ 497

Owyheeite (Silver Jamesonite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins greenish tinted greys 37.27 - 43.48 Bireflectance: strong, light to dark greenish tinted greys distinct



2/m 2/m 2/m ortho. 2/m 2/m 2/m

Descriptions A Anhedral owyheeite (slightly greenish tinted grey) between galena (light grey) and tetrahedrite (greenish grey); Banner District, Idaho, USA [j]; Nic. // B Owyheeite (lightest and darkest greenish tinted grey anisotropy), galena (isotropic, grey), tetrahedrite (isotropic, brownish); Banner District, Idaho, USA [j]; Nic. +

498

Owyheeite A

7μ

B

7μ 499

Dufrenoysite (Gotthardite, Plumbobinnite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal light grey rare, deep red 34.55 - 37.6 Bireflectance: strong, brown-violet and dark green very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.18-Dufrenoysite-Veenite series II/E.18-10 Dufrenoysite II/E.18-20 Veenite

Pb2As2S5 Pb2(Sb,As)2S5

2/m mm2

Descriptions A Dufrenoysite (light grey, scratches); Binn Valley, Wallis, Switzerland [e]; Nic. // B Dufrenoysite (dark brownish and greenish grey anisotropy, red internal reflections); Binn Valley, Wallis, Switzerland [e]; Nic. +

500

Dufrenoysite A

60 μ

B

60 μ 501

Falkmanite (Bolidenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal veins light to greenish grey [38] Bireflectance: weak distinct, light to dark bluish to brownish light grey to greenish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.19-Falkmanite-Jaskolskiite series II/E.19-10 Falkmanite II/E.19-20 Ardaite II/E.19-30 Boulangerite II/E.19-40 Plumosite II/E.19-42 Moeloite II/E.19-45 Pillaite II/E.19-50 Jaskolskiite

Pb5Sb4S11 Pb19Sb13S35Cl7 Pb5Sb4S11 Pb2Sb2S5 Pb6Sb6S14(S3) Pb9Sb10S23ClO0.5 Pb2.2Cu0.2(Sb,Bi)1.8S5

mono. mono. ortho. mono. 222 2/m 2/m 2/m 2/m

Descriptions A Anhedral falkmanite (light grey to greenish grey, slight bireflectance) intergrown with euhedral arsenopyrite (white) and pyrite (light yellow); Bayerland Mine, Fichtelgebirge, Germany [b]; Nic. // B Falkmanite (distinct anisotropy, light to dark bluish to brownish) arsenopyrite (here dark) and pyrite (dark); Bayerland Mine, Fichtelgebirge, Germany [b]; Nic. +

502

Falkmanite A

120 μ

B

120 μ 503

Boulangerite (Mullanite, Plumosite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low- to moderate-temperature hydrothermal veins medium grey, sometimes greenish tints 37.26 - 39.76 distinct weak

Bireflectance:

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.19-Falkmanite-Jaskolskiite series II/E.19-10 Falkmanite II/E.19-20 Ardaite II/E.19-30 Boulangerite II/E.19-40 Plumosite II/E.19-42 Moeloite II/E.19-45 Pillaite II/E.19-50 Jaskolskiite

A B C D E

Pb5Sb4S11 Pb19Sb13S35Cl7 Pb5Sb4S11 Pb2Sb2S5 Pb6Sb6S14(S3) Pb9Sb10S23ClO0.5 Pb2.2Cu0.2(Sb,Bi)1.8S5

mono. mono. ortho. mono. 222 2/m 2/m 2/m 2/m

Descriptions Prismatic boulangerite (lighter greys) in silicate matrix (medium grey); Oberlahr, Westerwald, Germany [a]; Nic. // Massive boulangerite aggregate (medium greys, see variation of bireflectance), sphalerite (medium grey); Bawdwin, Burma [d]; Nic. // Boulangerite (various grey shades, anisotropy), sphalerite (brown internal reflections); Bawdwin, Burma [d]; Nic. + Radial boulangerite aggregate (grey with bluish tint), colloform pyrite (cream), amorphous silica (dark grey); Mt. Jourdanne, Southwest Indian Ridge [c]; Nic. // Boulangerite (compare picture D; dark, red internal reflections along edge of aggregate), sphalerite (brown internal reflections), amorphous silica (greyish internal reflections); Mt. Jourdanne, Southwest Indian Ridge [c]; Nic. +

504

Boulangerite A

42 μ

C

B

125 μ

125 μ

D

E

38 μ

25 μ 505

Semseyite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal veins medium grey 35.08 - 41.99 Bireflectance: strong, grey-brown very weak

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.21-Rayite-Fülöppite series II/E.21-10 Rayite II/E.21-20 Semseyite II/E.21-30 Heteromorphite II/E.21-40 Plagionite II/E.21-50 Fülöppite

(Ag,Tl)2Pb8Sb8S21 Pb9Sb8S21 Pb7Sb8S19 Pb5Sb8S17 Pb3Sb8S15

2/m 2/m 2/m 2/m 2/m

Descriptions A Radial semseyite (medium grey, bireflectance almost invisible here) in silicate matrix (dark); Bey Dag, 42 km south of Zara, Vilayet Sivas, Turkey [f]; Nic. // B Semseyite (grey-brown anisotropy), silicates (multicolour internal reflections); Bey Dag, 42 km south of Zara, Vilayet Sivas, Turkey [f]; Nic. + C Semseyite (blue to brown grey anisotropy), silicates (multicolour internal reflections); Bey Dag, 42 km south of Zara, Vilayet Sivas, Turkey [f]; Nic. + (+2°)

506

Semseyite A

60 μ

C

B

125 μ

125 μ

507

Heteromorphite (Antimony Glance Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins medium greenish grey [30] Bireflectance: greenish to brownish to bluish grey



2/m 2/m 2/m 2/m 2/m

Descriptions A Massive heteromorphite (greenish grey) with unidentified alteration product(s) along fractures and cleavage (medium grey), quartz (dark grey); Kara-Kammar, Gissar Range, Tajikistan [j]; Nic. // B Heteromorphite (greenish to brownish to bluish grey anisotropy), alteration product(s) (dark), quartz (transparent, multicolour internal reflections); Kara-Kammar, Gissar Range, Tajikistan [j]; Nic. +

508

Heteromorphite A

60 μ

B

60 μ 509

Plagionite (Rosenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins grey shades 32.98 - 40.64 Bireflectance: greenish grey bluish to brownish greys

pronounced


A B C D E


2/m 2/m 2/m 2/m 2/m

Descriptions Lamellar twins of plagionite (different grey shades, pronounced bireflectance), quartz (dark grey); Pfannenberger Einigkeit Mine, Siegerland, Germany [g]; Nic. // Plagionite twins (strong greenish to dark grey anisotropy), quartz (white internal reflections); Pfannenberger Einigkeit Mine, Siegerland, Germany [g]; Nic. + Plagionite with pointed twins (different medium to dark grey anisotropy); Pfannenberger Einigkeit Mine, Siegerland, Germany [g]; Nic. + Plagionite (greenish grey anisotropy, twins), realgar (bright red internal reflections), quartz (white internal reflections); Pfannenberger Einigkeit Mine, Siegerland, Germany [g]; Nic. + Basal cuts of plagionite crystals (dull grey) intergrown with Zinckenite (lightest grey) and stannite (unusual brownish tint); San José Mine, Oruro, Cercado Province, Bolivia [c]; Nic. //

510

Plagionite A

120 μ

C

B

125 μ

250 μ

D

E

250 μ

125 μ 511

Jamesonite (Comuccite, Wolfsbergite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late stage mineral in low- to moderate-temperature hydrothermal PbAg-Zn veins medium grey with greenish tint 32.92 - 38.53 Bireflectance: minimal strong, dark to lighter brownish grey distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.22-Jamesonite-Sakharovaite series II/E.22-10 Jamesonite II/E.22-20 Benavidesite II/E.22-30 Parajamesonite II/E.22-40 Sakharovaite

Pb4FeSb6S14 Pb4(Mn,Fe)Sb6S14 Pb4FeSb6S14 (Pb,Fe)(Bi,Sb)2S4

2/m 2/m ortho. mono.

Descriptions A Finest fibres of jamesonite (different grey shades anisotropy, red internal reflections), anhedral stannite (bluish and greenish anisotropy); Itos Mine, Oruro, Bolivia [j]; Nic. + B Jamesonite needles (greenish grey) in galena (light grey); Kari Kari, Depto. Potosi, Bolivia [d]; Nic. // C Jamesonite (grey anisotropy), galena (dark); Kari Kari, Depto. Potosi, Bolivia [d]; Nic. +

512

Jamesonite A

41 μ

C

B

125 μ

125 μ

513

Ramdohrite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

fine-grained quartz in a hydrothermal vein medium grey with brownish tint 35.08 - 39.98 Bireflectance: moderate, light and dark brownish grey very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.23-Uchucchacuaite-Roshchinite series II/E.23-10 Uchucchacuaite II/E.23-20 Fizelyite II/E.23-30 Ramdohrite II/E.23-40 Andorite II/E.23-50 Roshchinite

AgPb3MnSb5S12 Pb14Ag5Sb21S48 Ag3Pb6Sb11S24 PbAgSb3S6 Ag19Pb10Sb51S96

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Massive ramdohrite (medium grey with brownish tint), jamesonite (euhedral shapes, slightly lighter grey), miargyrite (slightly darker bluish grey); Tatasí, Sud Chichas Province, Potosí Department, Bolivia [j]; Nic. // B Ramdohrite (light and dark brownish grey anisotropy), jamesonite (blue to bluish grey anisotropy), miargyrite (bluish grey anisotropy, specs of red internal reflections); Tatasí, Sud Chichas Province, Potosí Department, Bolivia [j]; Nic. +

514

Ramdohrite A

120 μ

B

120 μ 515

Andorite (Sundite, Webnerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal white 35.37 - 39.33

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.23-Uchucchacuaite-Roshchinite series II/E.23-10 Uchucchacuaite II/E.23-20 Fizelyite II/E.23-30 Ramdohrite II/E.23-40 Andorite II/E.23-50 Roshchinite

A B C D E

AgPb3MnSb5S12 Pb14Ag5Sb21S48 Ag3Pb6Sb11S24 PbAgSb3S6 Ag19Pb10Sb51S96

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Andorite (slight dark grey anisotropy, red internal reflections), silicates (whitish internal reflections); Real Socavon, Potosi, Bolivia [j]; Nic. + Aggregate of euhedral andorite (light grey), pyrite (cream), silicates (dark grey); Real Socavon, Potosi, Bolivia [j]; Nic. // Andorite (various greys anisotropy; less pronounced than in stibnite), pyrite (isotropic), silicates (white to brownish internal reflections); Real Socavon, Potosi, Bolivia [j]; Nic. + Prismatic andorite (light grey), anhedral stannite (grey with slight olive tint), euhedral pyrite (cream), silicates (dark grey); Real Socavon, Potosi, Bolivia [j]; Nic. // Andorite (various greys anisotropy in twins parallel to long axis), stannite (dark), pyrite (isotropic), silicates (brownish to white internal reflections); Real Socavon, Potosi, Bolivia [j]; Nic. +

516

Andorite A

18 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 517

Baumhauerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

dolomite related to high grade/temperature metamorphism grey deep red 34.14 - 38.35 Bireflectance: very faint strong, green, violet, blue-green or yellow

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.24-Baumhauerite-Robinsonite series II/E.24-10 Baumhauerite II/E.24-15 Baumhauerite-2a II/E.24-20 Robinsonite

Pb3As4S9 Pb3As4S9 Pb4Sb6S13

– 1 2/m 2/m

Descriptions A Massive baumhauerite (light grey), dolomite (dark grey); Lengenbach Mine, Binn Valley, Wallis, Switzerland [j]; Nic. // B Baumhauerite (brownish grey to dark brown anisotropy, relatively coarse twin lamellae, red internal reflections), dolomite (dark grey); Lengenbach Mine, Binn Valley, Wallis, Switzerland [j]; Nic. +

518

Baumhauerite A

60 μ

B

60 μ 519

Rathite (Wiltshireite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-grade/-temperature metamorphic Pb, Zn, As, Tl, Ba ores medium greenish to pinkish grey faint, deep red 32.53 - 37.60 Bireflectance: distinct intense, light bluish grey to dark blue greenish to pinkish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.25-Liveingite-Twinnite series II/E.25-10 Liveingite II/E.25-20 Rathite II/E.25-30 Sartorite II/E.25-40 Guettardite II/E.25-50 Twinnite

A

B

C

D

E

Pb9As13S28 Pb8Pb4-x(Tl2As2)x(Ag2As2)As16S40 PbAs2S4 Pb(Sb,As)2S4 Pb(Sb,As)2S4

2 2/m 2/m 2/m – 1

Descriptions Lamellar intergrowth of rathite (medium grey, bireflectance, compare next photo) and baumhauerite (slightly lighter grey than rathite); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. // Intergrowth of rathite (medium grey, bireflectance, compare previous photo) and baumhauerite (here slightly darker grey than rathite); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. // Rathite (lighter and darker grey anisotropy than baumhauerite, two twinning directions, faint red internal reflections along cracks), baumhauerite (rather homogeneous medium grey, faint red internal reflections along cracks); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. + Rathite (light bluish grey and darker grey anisotropy than baumhauerite, two twinning directions), baumhauerite (homogeneous medium and dark grey); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. + Rathite (here light to dark blue anisotropy, well-developed twinning), sartorite (dark), hutchinsonite (red internal reflections), pyrite (isotropic); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. +

520

Rathite A

60 μ

C

B

125 μ

125 μ

D

E

199 μ

208 μ 521

Sartorite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-grade/-temperature metamorphic Pb, Zn, As, Tl, Ba ores light grey rare, deep red 32.64 - 36.55 Bireflectance: weak, dark to olive and bluish grey hardly visible

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.25-Liveingite-Twinnite series II/E.25-10 Liveingite II/E.25-20 Rathite II/E.25-30 Sartorite II/E.25-40 Guettardite II/E.25-50 Twinnite

A

B

C D E

Pb9As13S28 Pb8Pb4-x(Tl2As2)x(Ag2As2)As16S40 PbAs2S4 Pb(Sb,As)2S4 Pb(Sb,As)2S4

2 2/m 2/m 2/m – 1

Descriptions Irregular sartorite (light grey) is replaced by hutchinsonite (mainly from edges, slightly darker bluish grey), dolomite (dark grey); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. // Sartorite(dark), hutchinsonite (strong red internal reflections, fine twin-lamellation with slightly differing anisotropy shades), dolomite (bright internal reflections); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. + Sartorite (dark and bluish grey anisotropy), dolomite (bright internal reflections); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. + Sartorite (dark olive grey, rare red internal reflections); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. + Sartorite (brownish grey), rathite (slightly darker anisotropy than sartorite, well-developed twinning with dark and bluish anisotropy), pyrite (isotropic), dolomite (bright internal reflections); Lengenbach Quarry, Binn Valley, Wallis, Switzerland [j]; Nic. +

522

Sartorite A

60 μ

C

B

125 μ

250 μ

D

E

125 μ

115 μ 523

Zinckenite (Keeleyite, Zinkenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins associated with base metal deposits grey-white 36.39 - 40.73 Bireflectance: distinct, bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.26-Zinckenite series II/E.26-10 Zinckenite II/E.26-20 Scainiite

A B C D

E

Pb9Sb22S42 Pb14Sb30S54O5

6 2/m

Descriptions Zinckenite (greenish to brownish grey anisotropy, minute specs of red internal reflections); Tornohuaico Mine, Porco, Potosí Department, Bolivia [j]; Nic. + Radial zinckenite (light greenish tinted grey) intergrown with sphalerite (medium grey); Tornohuaico Mine, Porco, Potosí Department, Bolivia [j]; Nic. // Zinckenite (greenish to brownish grey anisotropy, red internal reflections); Tornohuaico Mine, Porco, Potosí Department, Bolivia [j]; Nic. + Large striated crystals of zinckenite (light grey) intergrown with plagionite (slightly darker grey lamella) and stannite (unusual brownish colour); San José Mine, Oruro City, Cercado Province, Oruro Department, Bolivia [c]; Nic. // Longitudinal and basal cuts of zinckenite crystals (light grey) intergrown with stannite (unusual brownish colour); San José Mine, Oruro City, Cercado Province, Oruro Department, Bolivia [c]; Nic. //

524

Zinckenite A

60 μ

C

B

64 μ

3μ

D

E

88 μ

140 μ 525

Aikinite (Belonite, Patrinite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins cream-white 45.28 - 46.52 Bireflectance: distinct creamwhite to pure white or light brown

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.30-Aikinite-Pekoite series II/E.30-10 Aikinite II/E.30-15 Soucekite II/E.30-20 Friedrichite II/E.30-25 Emilite II/E.30-30 Hammarite II/E.30-40 Lindströmite II/E.30-50 Krupkaite II/E.30-54 Paarite II/E.30-60 Gladite II/E.30-70 Pekoite

A B C D E

PbCuBiS3 PbCuBi(S,Se)3 Pb5Cu5Bi7S18 Cu10.7Pb10.7Bi21.3S48 Pb2Cu2Bi4S9 Pb3Cu3Bi7S15 PbCuBi3S6 Cu1.7Pb1.7Bi6.3S12 PbCuBi5S9 PbCuBi11(S,Se)18

2/m 2/m 2/m mm2 mm2 mm2 2/m 2/m 2/m 2/m 2/m 2/m mm2 2/m 2/m 2/m 2/m 2/m 2/m mm2

Descriptions Massive and myrmekitic aikinite (tinted white), gangue minerals (dark); Beresowsk, Russia [e]; Nic. // Anhedral aikinite (creamish white) with safflorite rim (light grey) in galena matrix (medium grey); Beresowsk, Russia [d]; Nic. // Aikinite (brownish grey to grey anisotropy), safflorite (strong blue to brown anisotropy) in galena matrix (dark grey); Beresowsk, Russia [d]; Nic. + Anhedral aikinite (cream tint), molybdenite (grey shades, bireflectance); Zinngrube, Altenberg, Saxony, Germany [a]; Nic. // Aikinite (olive to bluish grey anisotropy), molybdenite (grey anisotropy); Zinngrube, Altenberg, Saxony, Germany [a]; Nic. +

526

Aikinite A

40 μ

C

B

250 μ

250 μ

D

E

50 μ

50 μ 527

Emilite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed scheelite deposit light grey [38] brownish grey

Bireflectance:



Descriptions A Anhedral emilite grain (light grey); Felbertal, Mittersill, Austria [h]; Nic. // B Emilite grain (brownish grey anisotropy); Felbertal, Mittersill, Austria [h]; Nic. +

528


Emilite A

60 μ

B

60 μ 529

Lindströmite (Lindstroemite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal light grey 40.52 - 45.21 Bireflectance: distinct, brownish grey to almost black




Descriptions A Lindströmite (light grey); Felbertal, Mittersill, Austria [h]; Nic. // B Lindströmite (here brownish grey anisotropy); Felbertal, Mittersill, Austria [h]; Nic. + C Lindströmite (here almost black anisotropy); Felbertal, Mittersill, Austria [h]; Nic. +

530

Lindströmite A

60 μ

C

B

125 μ

125 μ

531

Krupkaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

vein between gneiss and orthoclase pegmatite greyish white [35] Bireflectance: brownish grey to dark brown brownish to yellowish tinted greys

weak


A

B C D E



Descriptions Subhedral krupkaite (slight cream tint and bireflectance, center is replaced by fine-grained mineral mixture) intergrown with Ag-lillianite (slightly lighter grey on both sides of krupkaite), native silver (white) as part of fine-grained material; Felbertal, Mittersill, Austria [h]; Nic. // Krupkaite (medium brown anisotropy), Ag-lillianite (dark bluish and brownish anisotropy), native silver (isotropic, small white reflections); Felbertal, Mittersill, Austria [h]; Nic. + Krupkaite (brownish grey undulating anisotropy) intergrown with Ag-lillianite (light grey); Felbertal, Mittersill, Austria [h]; Nic. + Subhedral krupkaite (brownish grey, bireflectance) intergrown with Ag-lillianite (light grey); Felbertal, Mittersill, Austria [h]; Nic. // Krupkaite (yellowish tinted grey, bireflectance compare previous photo) intergrown with Aglillianite (light grey); Felbertal, Mittersill, Austria [h]; Nic. //

532

Krupkaite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 533

Paarite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed scheelite deposit light grey 48.00 - 36.85 Bireflectance: distinct, blue grey




Descriptions A Exsolution of paarite and krupkaite (both with very similar optical appearance, light grey), native silver (white); Felbertal, Mittersill, Austria [h]; Nic. // B Lamellar exsolution of paarite (blue grey anisotropy) and krupkaite (brown anisotropy); Felbertal, Mittersill, Austria [h]; Nic. +

534

Paarite A

46 μ

B

24 μ 535

Lillianite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins light grey [40] Bireflectance: not always distinct very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.31-Xilingolite-Gustavite series II/E.31-10 Xilingolite II/E.31-20 Lillianite II/E.31-30 Bursaite II/E.31-40 Ourayite II/E.31-50 Eskimoite II/E.31-60 Vikingite II/E.31-70 Schirmerite II/E.31-80 Treasurite II/E.31-90 Gustavite

Pb3Bi2S6 Pb3Bi2S6 Pb5Bi4S11 Pb4Ag3Bi5S13 Ag7Pb10Bi15S36 Ag5Pb8Bi13S30 Ag3Pb3Bi9S18 Ag7Pb6Bi15S32 PbAgBi3S6

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Ag-rich lillianite (light grey) partially replaced by fine-grained mineral mixture containing native silver (white) and other unidentified fine-grained minerals; Felbertal, Mittersill, Austria [h]; Nic. // B Ag-rich lillianite (light grey), native silver (isotropic, white reflections) and other unidentified fine-grained minerals; Felbertal, Mittersill, Austria [h]; Nic. +

536

Lillianite A

60 μ

B

60 μ 537

Kobellite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal grey shades 40.33 - 44.73 Bireflectance: distinct, brownish greys weak

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.33-Izoklakeite-Berryite series II/E.33-05 Izoklakeite II/E.33-10 Giessenite II/E.33-15 Tintinaite II/E.33-20 Kobellite II/E.33-30 Eclarite II/E.33-40 Nuffieldite II/E.33-50 Berryite

Pb27(Cu,Fe)2(Sb,Bi)19S57 Pb13(Cu,Ag)(Bi,Sb)9S28 Pb22Cu4(Sb,Bi)30S69 Pb22Cu4(Bi,Sb)30S69 Pb9(Cu,Fe)Bi12S28 Pb2Cu(Pb,Bi)Bi2S7 Pb3(Ag,Cu)5Bi7S16

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Massive kobellite (two grey shades, here with maximum bireflectance); Vena, Sweden [e]; Nic. // B Kobellite (brownish grey anisotropy); Vena, Sweden [e]; Nic. +

538

Kobellite A

60 μ

B

60 μ 539

Cosalite (Bjelkite, Pb-Bismutite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

moderate-temperature hydrothermal deposits, contact metasomatic replacements, epithermal replacements, pegmatites cream-white 40.37 - 43.56 weak weak

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/E.34-Cosalite-Galenobismuthite II/E.34-08 Mozgovaite II/E.34-10 Cosalite II/E.34-20 Proudite II/E.34-30 Weibullite II/E.34-60 Cannizzarite II/E.34-65 Wittite II/E.34-70 Nordströmite II/E.34-80 Junoite II/E.34-85 Felbertalite II/E.34-90 Watkinsonite II/E.34-100 Paderaite II/E.34-110 Galenobismuthite

PbBi4(S,Se)7 Pb2Bi2S5 (Pb,Cu)8Bi9-10(S,Se)22 Pb6Bi8(S,Se)18 Pb4Bi6S13 Pb3Bi4(S,Se)9 Pb3CuBi7(S10Se4) Pb3Cu2Bi8(S,Se)16 Cu2Pb6Bi8S19 PbCu2Bi4(Se,S)8 AgPb2Cu6Bi11S22 PbBi2S4

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m m 2/m 2/m 2/m 2/m

Descriptions A Anhedral cosalite (light grey); Felbertal, Mittersill, Austria [h]; Nic. // B Lamellar intergrowths of cosalite (white) and boulangerite (light grey), chalcopyrite (brownish yellow); Boliden, Sweden [f]; Nic. // C Cosalite (grey), boulangerite (strong blue grey to brown grey anisotropy), chalcopyrite (orange brown anisotropy); Boliden, Sweden [f]; Nic. + (+2°)

540

Cosalite A

60 μ

C

B

188 μ

188 μ

541

Weibullite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Cu mineralisation with minor Au in a hornblende rock greenish tinted grey 38.68 - 44.79 Bireflectance: strong, brownish grey shades weak

weak




Descriptions A Weibullite (grey to greenish grey pleochroism, bireflectance), chalcopyrite (dull yellow), quartz (dark); Falu mine, Falun, Dalarna, Sweden [j]; Nic. // B Weibullite (medium to darker grey anisotropy), chalcopyrite (dark greenish grey), quartz (transparent to multicolour internal reflections); Falu mine, Falun, Dalarna, Sweden [j]; Nic. +

542

Weibullite A

60 μ

B

60 μ 543

Cannizzarite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

deep-seated fumarolic activity light grey 48.02 - 50.22 Bireflectance: strong, from blue to grey




Descriptions A Euhedral cannizzarite (light grey) in rock fragments (dark grey); Vulcano, Lipari Islands, Italy [j]; Nic. // B Cannizzarite (blue anisotropy), rock fragments (various internal reflections; green = polishing material); Vulcano, Lipari Islands, Italy [j]; Nic. +

544

Cannizzarite A

5μ

B

5μ 545

Felbertalite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

quartz-scheelite discordant ore veins light grey [44] Bireflectance: dark brownish greys

slight




Descriptions A Anhedral felbertalite (light grey, slight bireflectance) intergrown with Ag-rich lillianite (slightly brighter than felbertalite, slight bireflectance); Felbertal, Mittersill, Austria [h]; Nic. // B Felbertalite (here dark grey anisotropy), Ag-rich lillianite (here brown grey anisotropy); Felbertal, Mittersill, Austria [h]; Nic. +

546

Felbertalite A

60 μ

B

60 μ 547

Galenobismuthite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal white 44.71 - 47.48 Bireflectance: strong, bluish to brownish




Descriptions A Anhedral galenobismuthite (almost white) intergrown with chalcopyrite (yellow), quartz (dark grey); Falun, Sweden [g]; Nic. // B Galenobismuthite (bluish to brownish anisotropy, irregular lamellae), chalcopyrite (relatively dark), quartz (white and multicolour internal reflections); Falun, Sweden [g]; Nic. +

548

Galenobismuthite A

120 μ

B

120 μ 549

Patronite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

V and Ni associated with organogenic material, such as lignite yellowish grey 19.38 - 31.00 Bireflectance: strong grey shades, similar to molybdenite

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.01-Patronite series II/F.01-10 Patronite

2/m

VS4

Descriptions A Anhedral patronite (slightly yellowish grey, strong bireflectance) and unidentified mineral (medium grey) in dehydration cracks of melanovanadite (brownish grey); Ragra Mine (Minasragra), Junín, Cerro de Pasco, Peru [j]; Nic. // B Patronite (strong anisotropy, similar to molybdenite), unidentified mineral (similar to melanovanadite), melanovanadite (brownish grey, slight anisotropy); Ragra Mine (Minasragra), Junín, Cerro de Pasco, Peru [j]; Nic. +

550

Patronite A

7μ

B

17 μ 551

Realgar Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal orange abundant, yellow to orange-red 19.27 Bireflectance: strong, not always clearly visible difficult to identify because of strong internal reflections

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.02-Duranusite-Jeromite series II/F.02-10 Duranusite II/F.02-20 Dimorphite II/F.02-30 Realgar II/F.02-40 Pararealgar II/F.02-50 Alacranite II/F.02-60 Uzonite II/F.02-70 Orpiment II/F.02-80 Laphamite II/F.02-90 Jeromite

A B C D E

As4S As4S3 AsS AsS As8S9 As4S5 As2S3 As2(Se,S)3 As(S,Se)2

ortho. 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m none

Descriptions Skeletal realgar (brownish grey), pyrite (white), goethite (medium grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Realgar (yellow internal reflections), pyrite (isotropic), goethite (dark), kermesite fibres (red internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Realgar (bright orange internal reflections), barite (white internal reflections), radial stibnite fibres (dark patches); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Euhedral realgar (medium grey) partially replaced by covellite (blue pleochroism) in barite and silica matrix (dark grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Realgar (orange internal reflections), covellite (orange anisotropy), barite and silica matrix (transparent, grey internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

552

Realgar A

60 μ

C

B

102 μ

125 μ

D

E

80 μ

80 μ 553

Orpiment Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal veins, hot springs, fumaroles, alteration of As minerals medium grey strong, orange to yellow 19.57 - 26.18 Bireflectance: strong, grey, anisotropy masked by strong internal reflections

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.02-Duranusite-Jeromite series II/F.02-10 Duranusite II/F.02-20 Dimorphite II/F.02-30 Realgar II/F.02-40 Pararealgar II/F.02-50 Alacranite II/F.02-60 Uzonite II/F.02-70 Orpiment II/F.02-80 Laphamite II/F.02-90 Jeromite

A B C D

E

As4S As4S3 AsS AsS As8S9 As4S5 As2S3 As2(Se,S)3 As(S,Se)2

ortho. 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m none

Descriptions Colloform orpiment (medium grey) with partial alteration (lamination), pyrite (white); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Orpiment (orange to yellow internal reflections), alteration (brown internal reflections), pyrite (isotropic); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Orpiment (bright red internal reflections; confirmed by microanalysis); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Radial orpiment (red and yellow internal reflections; confirmed by microanalysis) in amorphous silica matrix (various internal reflections from neighbours); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. + Orpiment (orange internal reflections) replaced by Cu salts (bright blue internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

554

Orpiment A

92 μ

C

B

188 μ

125 μ

D

E

80 μ

78 μ 555

Djerfisherite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Cu-Ni ores, skarns, pegmatites, kimberlites, mafic alkalic diatremes medium grey with brown tint 24.23

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.06-Djerfisherite-Thalfenisite series II/F.06-10 Djerfisherite II/F.06-20 Thalfenisite II/F.06-30 Owensite

K6Na(Fe,Cu,Ni)25S26Cl Tl6(Fe,Ni,Cu)25S26Cl (Ba,Pb)6(Cu,Fe,Ni)25S27

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Anhedral djerfisherite (medium grey with brown tint) in chalcopyrite (brownish olive), galena (medium grey), sobolevskite (pinkish tint), altaite (light grey with greenish tint, in and around sobolevskite); Oktjabrsky, Norilsk, Russia [h]; Nic. // B Djerfisherite (dark brown grey), chalcopyrite (dark olive), galena (isotropic), sobolevskite (relatively bright grey with violet tint), altaite (greenish grey); Oktjabrsky, Norilsk, Russia [h]; Nic. +

556

Djerfisherite A

60 μ

B

60 μ 557

Rasvumite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatites cream-grey 18.87 - 24.97 Bireflectance: strong, brownish grey strong

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.07-Rasvumite-Bartonite series II/F.07-10 Rasvumite II/F.07-20 Bartonite II/F.07-30 Chlorbartonite

KFe2S3 K3Fe10S14 K6Fe24S26(Cl,S)

2/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Irregular fibres of rasvumite (cream-grey), rutile (grey), silicates (dark grey); Coyote Peak, Orick, California, USA [a]; Nic. // B Rasvumite (brownish grey anisotropy), rutile (brown internal reflections), silicates (white and brown internal reflections); Coyote Peak, Orick, California, USA [a]; Nic. +

558

Rasvumite A

19 μ

B

19 μ 559

Bartonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alkalic diatreme yellowish green-grey to yellowish green-brown 23.01 - 23.42

Bireflectance:

very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.07-Rasvumite-Bartonite series II/F.07-10 Rasvumite II/F.07-20 Bartonite II/F.07-30 Chlorbartonite

KFe2S3 K3Fe10S14 K6Fe24S26(Cl,S)

2/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Euhedral bartonite (grey with brownish tint, distinct cleavage) partially intergrown with “dusty” unidentified mineral (brownish); Coyote Peak, Humboldt County, California, USA [a]; Nic. // B Bartonite (dark) in gang mineral matrix (various colours of internal reflections); Coyote Peak, Humboldt County, California, USA [a]; Nic. +

560

Bartonite A

60 μ

B

60 μ 561

Schöllhornite (Schoellhornite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

meteorites, alteration product of caswellsilverite medium grey 15.37 - 19.26 Bireflectance: strong distinct, light grey with bluish or greenish tint

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.08-Caswellsilverite-Schöllhornite series II/F.08-10 Caswellsilverite II/F.08-20 Schöllhornite II/F.08-30 Cronusite

NaCrS2 Na0.3CrS2·(H2O) Ca0.2(H2O)2CrS2

– 3 2/m 3m trig.

Descriptions A Anhedral schöllhornite (medium grey, round part of lower center grey grains) intergrown with daubreelite (similar medium grey, euhedral, extension to right) in troilite (light brownish tint), schreibersite (light cream); Indarch meteorite, Shusha, Elisavetpol, Azerbaidzhan [h]; Nic. // B Schöllhornite (bluish black, anisotropy not visible here), daubreelite , (similar shade), troilite (dark brownish grey), schreibersite (darkest brown); Indarch meteorite, Shusha, Elisavetpol, Azerbaidzhan [h]; Nic. +

562

Schöllhornite A

5μ

B

5μ 563

Cronusite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration of caswellsilverite, disseminated in enstatite medium grey 16.20 - 18.30 Bireflectance: strong, not always visible grey

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.08-Caswellsilverite-Schöllhornite series II/F.08-10 Caswellsilverite II/F.08-20 Schöllhornite II/F.08-30 Cronusite

NaCrS2 Na0.3CrS2·H2O Ca0.2(H2O)2CrS2

– 3 2/m 3m trig.

Descriptions A Anhedral cronusite grain (medium grey, irregular cracks); Norton County Enstatite Achondrite, Kansas, USA [h]; Nic. //

564

Cronusite A

12 μ

565

Erdite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late segregations in a mafic alkalic diatreme orange to blue-grey 8.76 - 24.56 Bireflectance: strong orange to brownish pronounced, orange to greenish or bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.09-Erdite-Coyoteite series II/F.09-10 Erdite II/F.09-20 Coyoteite

NaFeS2·2H2O NaFe3S5·2H2O

2/m tri.

Descriptions A Assemblage of loose erdite needles (orange to brownish anisotropy), silicate matrix (white, grey, brown internal reflections); Coyote Peak, Humboldt County, California, USA [a]; Nic. + B Fine needles of erdite (strong pleochroism from orange to bluish grey) in silicate matrix (grey shades); Coyote Peak, Humboldt County, California, USA [a]; Nic. // C Erdite (orange to brownish anisotropy), silicate matrix (white, grey, brown internal reflections); Coyote Peak, Humboldt County, California, USA [a]; Nic. +

566

Erdite A

20 μ

C

B

8μ

8μ

567

Kermesite (Pyrantimonite, Red Antimony Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of stibnite medium grey bright red in fine aggregates, in coarser material sometimes difficult to see 24.22 - 29.22 Bireflectance: strong, violet to greenish grey shades, in fine needles difficult to identify grey-brown to olive

Strunz Classification - Group Members - Chemical Formula - Crystallography II/F.11-Kermesite-Cetineite series II/F.11-10 Kermesite II/F.11-20 Sarabauite II/F.11-30 Cetineite

Sb2S2O CaSb10O10S6 (K,Na)3+x(Sb2O3)3(Sb2S3)(OH)x·2.8-xH2O

– 1 2/m 6

Descriptions A Fibrous kermesite (light grey, difficult to identify, similar to stibnite, red internal reflections through silicate matrix), sphalerite (medium grey patches); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // B Kermesite (bright red internal reflections), sphalerite (isotropic), realgar (yellow); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

568

Kermesite A

44 μ

B

44 μ 569

Bravoite (Hengleinite, Mechernichite, Nickelian Pyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

mafic/ultramafic rocks, alteration product of pentlandite cream to brown 37.67 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography II/X.00-Antimonide II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00 II/X.00-00

A B C D E

IMA2004-020 Naldretteite Cupromakovickyite Milotaite IMA2004-047 IMA2003-039 Imgreite Bravoite Gabrielite IMA2004-048 Vihorlatite Catamarcaite Horobetsuite Angelaite IMA2004-031 IMA2004-005 IMA2004-032 Wilhelmramsayite Marumoite Bismutoplagionite IMA2000-044 IMA2001-002 Kudriavite Rouxelite Vurroite Dilithium

Pd4Sb3 Pd2Sb Cu4AgPb2Bi9S18 PdSbSe PdAsSe Pb2(Pb,Sb)2S8[Te,Au]2 NiTe (Fe,Ni,Co)S2 Tl6Ag3Cu6As9S21 Ag3CuSe2 Bi8+x(Se,Te,S)11-x Cu6GeWS8 (Bi,Sb)2S3 Cu2AgPbBiS4 AuBi5S4 CsFe2S3 Pb2AsS3(I,Cl) Cu3FeS3·2H2O Pb32As40S92 5PbS·4Bi2S3 Pb1.6Cu1.6Bi6.4S12 Cu17Bi17S35 (Cd,Pb)Bi2S4 Cu2HgPb23Sb27S65.5 Pb21SnAs11Bi11S50Cl8Se Li2Te

422 2/m 2/m 2/m 2/m 23 4/m 2/m 2/m 2/m 6/m 2/m 2/m – 2/m 3 1 4/m 2/m 2/m trig. hex. 2/m 2/m 2/m 2/m cub. 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2 ortho. mm2 2/m 2/m mono. mm2 222

Descriptions Irregular bravoite (brownish, cleavage) in pyrite (cream-white), ilmenite (medium grey); Telnes, Norway [b]; Nic. // Euhedral bravoite (slightly brownish cream) with core of pyrite (cream), chalcopyrite (brownish yellow); NE-Silverside, Zimbabwe [d]; Nic. // Concentric laminae of bravoite (light violet grey) in pyrite (light cream); Himmelsfürst Mine, Freiberg, Germany [g]; Nic. // Bravoite (light brown), pyrite (cream), and marcasite (bluish grey) replacing fossil wood (here only outlines by sulfides); Huscon mine, Arizona, USA [f]; Nic. // Subhedral bravoite (light brownish tint) and pyrophanite (medium grey) in bustamite matrix (dark grey); Noda-Tamagawa mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. //

570

Bravoite A

44 μ

C

B

102 μ

27 μ

D

E

76 μ

180 μ 571

Chlorargyrite (Argyroceratite, Cerargyrite, Horn Silver, Kerargyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised Ag ores medium grey light green [20] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography III/A.02-Halite series Griceite-Bromargyrite III/A.02-05 Griceite III/A.02-10 Villiaumite III/A.02-20 Carobbiite III/A.02-30 Halite III/A.02-40 Sylvite III/A.02-50 Chlorargyrite III/A.02-60 Bromargyrite

A B C D E

LiF NaF KF NaCl KCl AgCl AgBr

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions Chlorargyrite (light green internal reflections) with native silver (here brownish) outlining growth zones; Broken Hill, Australia [c]; Nic. + Euhedral chlorargyrite (medium grey) in quartz matrix (darker grey); Broken Hill, Australia [c]; Nic. // Chlorargyrite (light green internal reflections) with native silver (here brownish), quartz (white internal reflections); Broken Hill, Australia [c]; Nic. + Anhedral chlorargyrite (brownish grey, scratches), tetrahedrite (light grey), barite (dark grey laths); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Chlorargyrite (light green internal reflections), tetrahedrite (isotropic), native silver (brownish), barite (white internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

572

Chlorargyrite A

53 μ

C

B

250 μ

250 μ

D

E

141 μ

141 μ 573

Iodargyrite (Argyrojodite, Jodite, Jodargyrite, Jodyrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised silver ores medium grey bright yellow to brilliant [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography III/A.03-Jodargyrite-Tocornalite series III/A.03-10 Iodargyrite III/A.03-20 Tocornalite

AgI (Ag,Hg)I

6mm hex.

Descriptions A Sub-hedral iodargyrite (medium grey, scratches, some internal reflections; Broken Hill, Australia [c]; Nic. // B Sub-hedral iodargyrite (bright internal reflections; Broken Hill, Australia [c]; Nic. +

574

Iodargyrite A

120 μ

B

120 μ 575

Calomel (Horn Quicksilver) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration of Hg-carrying minerals yellowish grey to grey yellowish [18] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography III/A.05-Calomel-Moschelite series III/A.05-10 Calomel III/A.05-20 Kuzminite III/A.05-30 Moschelite

Hg2Cl2 Hg2(Br,Cl)2 Hg2I2

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Calomel (white internal reflections), cinnabar (bright red internal reflections, strong anisotropy), goethite (diffuse brown internal reflections); Landsberg Mt., Obermoschel, Rhineland Palatinate, Germany [j]; Nic. + B Anhedral calomel grains (light grey) in siliceous matrix (darker grey); Landsberg Mt., Obermoschel, Rhineland Palatinate, Germany [j]; Nic. // C Calomel grains (white internal reflections), siliceous matrix (greyish internal reflections); Landsberg Mt., Obermoschel, Rhineland Palatinate, Germany [j]; Nic. +

576

Calomel A

48 μ

C

B

32 μ

32 μ

577

Fluorite (Fluor Spar) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal veins to greisen deposits dark grey colourless, green, yellow, pink, violet, blue [4] Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography III/A.08-Fluorite series and related compounds III/A.08-10 Fluorite CaF2 III/A.08-20 Frankdicksonite BaF2 III/A.08-25 Haleniusite-(La) (La,Ce)OF III/A.08-30 Tveitite-(Y) Ca1-xYxF2+x III/A.08-40 Gagarinite-(Y) NaCaY(F,Cl)6 III/A.08-45 Zajacite-(Ce) Na(REExCa1-x)(REEyCa1-y)F6 III/A.08-50 Laurelite Pb7F12Cl2 III/A.08-60 Coccinite HgI2

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m mono. – 3 – 3 – 6 4/m 2/m 2/m

Descriptions A Fluorite (darkest grey) intergrown with quartz (dark grey) and arsenopyrite (white); Horni Slavkov, Czech Republic [b]; Nic. // B Fluorite (zonation of violet to almost colourless internal reflections), quartz (lighter grey), arsenopyrite (here dark); Horni Slavkov, Czech Republic [b]; Nic. +

578

Fluorite A

60 μ

B

60 μ 579

Atacamite (Chlorochalcite, Paratacamite, Remolinite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

arid climates with oxidisable copper minerals, submarine dark grey bright green [10] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography III/D.01-Atacamite series, Korshunovskite-Anthonyite III/D.01-10 Korshunovskite Mg2Cl(OH)3·3.5-4H2O III/D.01-12 Nepskoeite Mg4Cl(OH)7·6H2O III/D.01-15 Hibbingite (Fe,Mg)2(OH)3Cl III/D.01-20 Kempite Mn2Cl(OH)3 III/D.01-25 Belloite Cu(OH)Cl III/D.01-30 Atacamite Cu2Cl(OH)3 III/D.01-40 Clinoatacamite Cu2(OH)3Cl III/D.01-50 Botallackite Cu2Cl(OH)3 III/D.01-55 Paratacamite (Cu,Zn)2(OH)3Cl III/D.01-57 Herbertsmithite Cu3Zn(OH)6Cl2 III/D.01-60 Melanothallite Cu2OCl2 III/D.01-65 Bobkingite Cu5Cl2(OH)8·2H2O III/D.01-70 Calumetite Cu(OH,Cl)2·2H2O III/D.01-80 Anthonyite Cu(OH,Cl)2·3H2O

tri. ortho. 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 3 – 3 2/m 2/m 2/m 2/m 2/m ortho. mono.

Descriptions A Eudedral atakamite mosaic (medium grey) in goethite matrix (slightly darker grey); Logatchev hydrothermal field (leg. Katja Schmidt) [c]; Nic. // B Atakamite mosaic (bright green), goethite matrix (light brown); Logatchev hydrothermal field (leg. Katja Schmidt) [c]; Nic. +

580

Atacamite A

60 μ

B

60 μ 581

Cuprite (Chalcotrichite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Cu deposits bluish grey red 24.62 - 25.5 Bireflectance: anomalous, greenish to bluish anisotropy anomalous, slight bluish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.02-Cuprite series IV/A.02-10 Cuprite

A B C D

E

Cu2O

– 4/m 3 2/m

Descriptions Myrmekitic intergrowth of cuprite (bluish grey) and galena (light grey); unknown locality [a]; Nic. // Euhedral cuprite (bluish grey) in limonite matrix (dark brownish grey); unknown locality [a]; Nic. // Cuprite (red internal reflections), limonite (orange internal reflections); unknown locality [a]; Nic. + Anhedral cuprite (bluish grey), chalcocite (slightly more bluish than cuprite, round grain), and native copper (pink) cementing quartz grains and some malachite (both darkest grey); Zambia [b]; Nic. // Cuprite (red internal reflections), chalcocite (dark), native copper (anisotropic scratches), quartz (bright internal reflections), malachite (green internal reflections); Zambia [b]; Nic. +

582

Cuprite A

25 μ

C

B

125 μ

125 μ

D

E

68 μ

68 μ 583

Zincite (Red Zinc Oxide, Spartalite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high grade/temperature metamorphosed weathered ore deposit medium grey strong, red to yellow 11.51 - 11.76 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.03-Brommelite-Zincite series IV/A.03-10 Bromellite IV/A.03-20 Zincite

BeO (Zn,Mn)O

6mm 6mm

Descriptions A Anhedral zincite (medium grey) extending into willemite (darkest grey), euhedral jacobsite (lightest grey); Sterling mine, New Jersey, USA [d]; Nic. // B Zincite (yellow to red internal reflections), willemite (“dusty” red to white internal reflections), jacobsite (isotropic); Sterling mine, New Jersey, USA [d]; Nic. + C Zincite (bright yellow to red internal reflections, well-developed cleavage, exsolution of hausmannite lamellae); Sterling mine, New Jersey, USA [j]; Nic. +

584

Zincite A

120 μ

C

B

250 μ

125 μ

585

Wüstite (Wuestite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

heavy mineral fraction of tuff (Scharnhausen, Germany), industrial mineral medium grey 18.65 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.04-Periclase Group, Periclase-Murdochite series IV/A.04-10 Periclase MgO IV/A.04-20 Wüstite FeO IV/A.04-30 Bunsenite NiO IV/A.04-40 Manganosite MnO IV/A.04-50 Monteponite CdO IV/A.04-60 Lime CaO IV/A.04-70 Murdochite PbCu6O8-x(Cl,Br)2x

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Skeletal wüstite (medium grey) in matrix of various unidentified alloys (yellow and bluish grey); artificial [c]; Nic. // B Myrmekitic wüstite (medium grey), silicate matrix (dark grey), unidentified alloys (yellow and bluish grey); artificial [c]; Nic. //

586

Wüstite A

24 μ

B

24 μ 587

Manganosite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Mn deposits medium grey emerald-green 13.56 Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.04-Periclase Group, Periclase-Murdochite series IV/A.04-10 Periclase MgO IV/A.04-20 Wüstite FeO IV/A.04-30 Bunsenite NiO IV/A.04-40 Manganosite MnO IV/A.04-50 Monteponite CdO IV/A.04-60 Lime CaO IV/A.04-70 Murdochite PbCu6O8-x(Cl,Br)2x

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Anhedral manganosite (medium grey) with oxidation rim of fibrous hausmannite (slightly darker; at upper contact); Noda Tamagawa, Japan [l]; Nic. // B Anhedral manganosite (green internal reflections), fibrous hausmannite (orange/brown); Noda Tamagawa, Japan [l]; Nic. //

588

Manganosite A

60 μ

B

60 μ 589

Tenorite (Black Copper Oxide, Melakonite, Melanoconite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Cu minerals brownish fine, red 19.46 - 29.41 Bireflectance: strong strong, dark brownish to bluish grey light brown dark brown

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.05-Periclase Group, Tenorite-Crednerite series IV/A.05-10 Tenorite CuO IV/A.05-20 Paramelaconite Cu4O3 IV/A.05-30 Delafossite CuFeO2 IV/A.05-40 Mcconnellite CuCrO2 IV/A.05-50 Crednerite CuMnO2

A B C D E

2/m 4/m 2/m 2/m – 3 2/m – 3 2/m 2/m

Descriptions Fibrous tenorite (brownish, bireflectance), cuprite (blue grey), chalcocite (grey); Tambao, Burkina Faso [d]; Nic. // Anhedral tenorite (brownish grey shades, distinct bireflectance) filling cracks of chrysocolla (dark grey); Superior Mine, Superior, Michigan, USA [j]; Nic. // Tenorite (distinctive dark to brownish to bluish grey anisotropy), chrysocolla (turquoise internal reflections); Superior Mine, Superior, Michigan, USA [j]; Nic. + Tenorite crystals (brownish grey) in chrysocolla matrix (dark grey); Superior Mine, Superior, Michigan, USA [j]; Nic. // Tenorite (distinctive dark to brownish to bluish grey anisotropy), chrysocolla (turquoise internal reflections); Superior Mine, Superior, Michigan, USA [j]; Nic. +

590

Tenorite A

60 μ

C

B

50 μ

50 μ

D

E

83 μ

83 μ 591

Paramelaconite (Paratenorite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration/oxidation product of Cu minerals cream to brown faint, brown [15] Bireflectance: weak distinctive brown to blue grey cream to brown


2/m 4/m 2/m 2/m – 3 2/m – 3 2/m 2/m

Descriptions A Radiating paramelaconite crystals (brown to grey pleochroism, bireflectance) in malachite (brownish grey with occasional greenish tint from internal reflections, bireflectance), goethite (bluish grey); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. // B Paramelaconite (dark brown to blue anisotropy), malachite (green internal reflections), goethite (brown internal reflections); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. +

592

Paramelaconite A

24 μ

B

24 μ 593

Delafossite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

secondary mineral near base of oxidation zone of Cu deposits mottled medium grey 19.25 - 23 Bireflectance: strong, bluish to brownish

slight


A B C D E

2/m 4/m 2/m 2/m – 3 2/m – 3 2/m 2/m

Descriptions Colloform delafossite (mottled medium grey, slight bireflectance), native copper (copper-red), goethite laminae (darker grey); Bisbee, Arizona, USA [e]; Nic. // Colloform delafossite (mottled medium grey, slight bireflectance), native copper (copper-red), goethite laminae (darker grey); Bisbee, Arizona, USA [e]; Nic. // Delafossite (bluish to brownish grey anisotropy), copper (reddish, dark, scratches), goethite (orange internal reflections, greyish anisotropy); Bisbee, Arizona, USA [e]; Nic. + Euhedral partially deformed delafossite laths (medium grey, bireflectance almost invisible), native copper (copper-red); Bisbee, Arizona, USA [e]; Nic. // Delafossite (bluish to brownish grey anisotropy), copper (reddish, dark, scratches); Bisbee, Arizona, USA [e]; Nic. +

594

Delafossite A

239 μ

C

B

117 μ

117 μ

D

E

250 μ

250 μ 595

Crednerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

secondary mineral at low temperatures and reducing conditions light grey 23.21 - 33.43 Bireflectance: strong, white to blue-grey yellowish to brownish grey

strong


2/m 4/m 2/m 2/m – 3 2/m – 3 2/m 2/m

Descriptions A Anhedral crednerite (lighter grey), partially twinned (note strong bireflectance), intergrown with hausmannite (darker grey); Långban, Sweden [c]; Nic. // B Crednerite (lightest grey shades, strong bireflectance), braunite crystals (medium grey) in marokite matrix (pinkish grey), henritermierite (lighter one of dark greys), other silicates (darkest grey); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. // C Crednerite (strong white to blue anisotropy, twin lamellae), braunite (brownish grey anisotropy, some brown internal reflections), marokite (relatively dark brownish grey anisotropy), henritermierite (brown internal reflections), other silicates (milky internal reflections); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. +

596

Crednerite A

25 μ

C

B

100 μ

100 μ

597

Litharge (Goldglätte) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alkaline pegmatites, hydrothermal Pb-Cu-Ag-Zn-Au-Mo-V-BariteFluorite-Silica veins darker grey with orange hue from strong internal reflections bright orange-red [10] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.06-Periclase Group, Montroydite-Massicotite series IV/A.06-10 Montroydite HgO IV/A.06-20 Litharge PbO IV/A.06-30 Massicot PbO

2/m 2/m 2/m 4/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Void filling litharge (grey with orange hue from strong internal reflections), native lead (light grey, compare reflectivity of this freshly polished material with native lead sample), quartz grains (dark grey); most likely artificial material from Mendoza, Argentina [j]; Nic. // B Litharge (bright orange-red internal reflections), native lead (dark with slight anomalous anisotropy), quartz (multicolour internal reflections); most likely artificial material from Mendoza, Argentina [j]; Nic. +

598

Litharge A

60 μ

B

60 μ 599

Massicot (Lead Monoxide) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of galena medium grey white, yellow, brownish grey [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/A.06-Periclase Group, Montroydite-Massicotite series IV/A.06-10 Montroydite HgO IV/A.06-20 Litharge PbO IV/A.06-30 Massicot PbO

2/m 2/m 2/m 4/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Aggregate of massicot platelets (medium grey), minium (similar grey but with orange tint from internal reflections); Revier Graben, Mezica (Miess), Slovenia [j]; Nic. // B Massicot (medium grey) replacing galena (light grey), minium (grey similar to massicot, in places orange tint from internal reflections); Revier Graben, Mezica (Miess), Slovenia [j]; Nic. // C Massicot (light yellow internal reflections), galena (isotropic), minium (strong orange internal reflections); Revier Graben, Mezica (Miess), Slovenia [j]; Nic. +

600

Massicot A

39 μ

C

B

50 μ

50 μ

601

Hercynite (Chrysomelane, Ferro-spinel, Iron Spinel, Skorian) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic dark grey green to brown [10] isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.01-Spinel group, Spinel-Gahnite series IV/B.01-10 Spinel IV/B.01-20 Hercynite IV/B.01-30 Galaxite IV/B.01-40 Gahnite

MgAl2O4 FeAl2O4 (Mn,Mg)(Al,Fe)2O4 ZnAl2O4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Hercynite grain (dark grey) with oriented intergrowth/exsolution of ilmenite needles (brownish grey anisotropy); Natschetin, Pobezovice (Ronsberg), Czech Republic [j]; Nic. // B Aggregate of hercynite (dark grey), interstitial goethite (lighter bluish grey); Natschetin, Pobezovice (Ronsberg), Czech Republic [j]; Nic. // C Hercynite (isotropic, green to brown internal reflections), goethite (red brown internal reflections); Natschetin, Pobezovice (Ronsberg), Czech Republic [j]; Nic. +

602

Hercynite A

20 μ

C

B

125 μ

125 μ

603

Galaxite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

carbonate-rich, silica-undersaturated parts of metamorphosed Mn deposit dark grey indistinct, various colours [5] Bireflectance: isotropic, oxidised specimens show slight grey anisotropy



– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Granular galaxite (medium grey) in carbonate matrix (dark grey, bireflectance); Kaso Mine, Kanuma, Tochigi Prefecture, Honshu Island, Japan [j]; Nic. // B Galaxite (isotropic), carbonates (diffuse internal reflections of various colours, greyish anisotropy); Kaso Mine, Kanuma, Tochigi Prefecture, Honshu Island, Japan [j]; Nic. +

604

Galaxite A

24 μ

B

24 μ 605

Gahnite (Automolite, Gahnospinel, Zinc Spinel) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphic rocks, pegmatites dark grey light to bottle-green [5] Bireflectance: isotropic


A B C

D E


– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions Subhedral gahnite grains (darker grey, almost like silicates), pyrrhotite (pinkish grey), galena (light grey), ilmenite (brownish grey), silicates (dark grey); Viitasaari, Finland [j]; Nic. // Subhedral gahnite grains (darker grey, almost like silicates), massive sphalerite (medium grey), galena (light grey), silicates (dark grey); Viitasaari, Finland [j]; Nic. // Gahnite (bright internal reflections, slight green tint), sphalerite (isotropic, some brown internal reflections), galena (isotropic, slightly brighter than sphalerite), silicates (bright internal reflections); Viitasaari, Finland [j]; Nic. + Large aggregates of gahnite (lightest grey) with interstitial quartz (darkest grey); Old Gipps Mine, Broken Hill, New South Wales, Australia [j]; Nic. // Gahnite (green internal reflections), quartz (bright internal reflections; Old Gipps Mine, Broken Hill, New South Wales, Australia [j]; Nic. +

606

Gahnite A

60 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 607

Magnetite (Magnetic Iron Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

accessory mineral in igneous and metamorphic rocks, biogenic product pinkish grey 20.60 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.02-Spinel group, Magnesioferrite-Franklinite series IV/B.02-10 Magnesioferrite MgFe2O4 IV/B.02-20 Magnetite Fe3O4 IV/B.02-30 Jacobsite (Mn,Fe,Mg)(Fe,Mn)2O4 IV/B.02-40 Trevorite NiFe2O4 IV/B.02-50 Cuprospinel (Cu,Mg)Fe2O4 IV/B.02-60 Franklinite (Zn,Mn,Fe)(Fe,Mn)2O4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Euhedral magnetite (pinkish grey) replaces hematite (light grey blades), carbonate (dark grey); Monte Calamita mine, Elba, Italy [b]; Nic. // B Euhedral magnetite (brownish grey) with crystallographically oriented hematite replacement (light grey); Bushveld, South Africa [b]; Nic. // C Skeletal magnetite (pinkish grey; chilled Etruscan slag) in silicate matrix (darker grey); Populonia, Tuscany, Italy [b]; Nic. //

608

Magnetite A

60 μ

C

B

30 μ

50 μ

609

Jacobsite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Mn deposits, alteration product of other Mn-bearing minerals brownish grey rare, dark red 17.31 Bireflectance: isotropic


Descriptions A Jacobsite (medium grey) in silicate matrix; Långban, Sweden [c]; Nic. // B Jacobsite (dark) in silicate matrix; Långban, Sweden [c]; Nic. +

610

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Jacobsite A

60 μ

B

60 μ 611

Franklinite (Zincoferrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

weathered and metamorphosed Zn-rich orebody light grey dark red 17.62 Bireflectance: isotropic


– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Euhedral franklinite (light grey) in carbonate (medium grey); Franklin, New Jersey, USA [a]; Nic. // B Franklinite (isotropic, dark red internal reflections), carbonate (white internal reflections); Franklin, New Jersey, USA [a]; Nic. + C Franklinite (dark greys, slightly anisotropic), silicate (bright internal reflections); Sterling mine, New Jersey, USA [d]; Nic. +

612

Franklinite A

201 μ

C

B

125 μ

250 μ

613

Chromite (Chromeferrite, Siderochrome) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

cumulate mineral in ultramafics, meteorites grey with brownish tint brownish red (rare, only in thinnest sections) 11.76 Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.03-Spinel group, Magnesio-chromite-Zinco-chromite series IV/B.03-10 Magnesiochromite MgCr2O4 IV/B.03-20 Chromite FeCr2O4 IV/B.03-30 Manganochromite (Mn,Fe)(Cr,V)2O4 IV/B.03-40 Cochromite (Co,Ni,Fe)(Cr,Al)2O4 IV/B.03-50 Nichromite (Ni,Co,Fe)(Cr,Fe,Al)2O4 IV/B.03-60 Zincochromite ZnCr2O4

A B C D E

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions Slightly rounded euhedral chromite (medium grey), silicates (dark grey); Zwartfontein, Potgietersrust, South Africa [a]; Nic. // Anhedral chromite (medium grey) between silicates (dark grey), small pyrite grains (yellow); Merensky Reef, Rustenburg, South Africa [c]; Nic. // Cataclastic chromite (medium grey) between silicates (dark grey); Merensky Reef, Rustenburg, South Africa [c]; Nic. // Euhedral chromite (pure grey) in magnetite (brownish grey), hematite (light grey lamellae); Great Dyke, Shabani, Zimbabwe [a]; Nic. // Slice of euhedral chromite (brown internal reflections in thinnest part), partially serpentinised olivin as matrix (bright to yellow internal reflections); Vardos, Greece [b]; Nic. +

614

Chromite A

60 μ

C

B

500 μ

250 μ

D

E

50 μ

50 μ 615

Ulvite (Ulvöspinel, Ulvospinel) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

exsolutions in titanomagnetite brownish grey 18.38 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.04-Spinel group, Vuorelainenite-Brunogeierite series IV/B.04-05 Magnesiocoulsonite MgV2O4 IV/B.04-10 Vuorelainenite (Mn,Fe)(V,Cr)2O4 IV/B.04-20 Coulsonite FeV2O4 IV/B.04-30 Qandilite (Mg,Fe)2(Ti,Fe,Al)O4 IV/B.04-40 Ulvite TiFe2O4 IV/B.04-50 Brunogeierite (Ge,Fe)Fe2O4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Ulvite exsolution lamellae (darker grey) in titanomagnetite (medium grey), sub-rounded silicate grains (darker grey); Småland Taberg, Sweden [b]; Nic. // B Ulvite (dark) and finer ilmenite exsolution lamellae (lighter grey, pleochroitic), titanomagnetite (dark grey); Småland Taberg, Sweden [b]; Nic. + (+2°)

616

Ulvite A

40 μ

B

40 μ 617

Hausmannite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, metamorphic manganiferous rocks medium grey deep blood red to reddish brown to orange 20.06 - 15.81 Bireflectance: weak distinct, greenish grey to dark

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.05-Hausmannite-Filipstadite series IV/B.05-10 Hausmannite IV/B.05-20 Iwakiite IV/B.05-30 Donathite IV/B.05-40 Hetaerolite IV/B.05-50 Hydrohetaerolite IV/B.05-60 Marokite IV/B.05-65 Tegengrenite IV/B.05-80 Filipstadite

A B C D

E

Mn3O4 Mn(Fe,Mn)2O4 (Fe,Mg)(Cr,Fe)2O4 ZnMn2O4 Zn2Mn4O8·H2O CaMn2O4 (Mg,Mn)2Sb0.5(Mn,Si,Ti)0.5O4 (Mn,Mg)4SbFeO8

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 2/m 2/m 2/m trig. 2/m 2/m 2/m

Descriptions Hausmannite (prominent red internal reflection, greenish grey and dark anisotropy); unknown locality [a]; Nic. + Anhedral hausmannite (twin with different grey shades, bireflectance); unknown locality [a]; Nic. // Hausmannite (partially lamellated, small red internal reflections, greenish to grey to dark anisotropy); unknown locality [a]; Nic. + The breakdown of the metastable vredenburgite produced hausmannite lamellae (brownish grey, slightly brighter than jacobsite) in jacobsite (slightly mottled brownish grey); Sterling Mine, Ogdensburg, Franklin Mining District, New Jersey, USA [j]; Nic. // Vredenburgite: hausmannite lamellae (brownish to bluish grey, anisotropy), jacobsite isotropic); Sterling Mine, Ogdensburg, Franklin Mining District, New Jersey, USA [j]; Nic. +

618

Hausmannite A

52 μ

C

B

86 μ

86 μ

D

E

250 μ

250 μ 619

Hetaerolite (Hetairite, Wolftonite, Zinc-Hausmannite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Mn deposits grey with brownish tint fine red specs 14.11 - 17.71 Bireflectance: strong, bluish to brownish grey

weak




Descriptions A Mainly anhedral hetaerolite (grey with brownish tint, colloform) intergrown with chalcophanite (elongated crystals, various grey shades, bireflectance), hemimorphite (dark needles); Broken Hill, Australia [c]; Nic. // B Hetaerolite (bluish to brownish grey anisotropy, small red internal reflections), chalcophanite (bright to dark grey shades anisotropy), hemimorphite (colourless internal reflections); Broken Hill, Australia [c]; Nic. +

620

Hetaerolite A

52 μ

B

52 μ 621

Hydrohetaerolite (Hetairite, Wolftonite, Zinc-Hausmannite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Mn deposits medium grey few, brown [17] Bireflectance: distinct, brown to grey shades




Descriptions A Elongated grains of hydrohetaerolite (medium grey) partially replaced by romanéchite (light grey) along grain boundaries; from original description by Ramdohr: most likely Skorpion Mine, Rosh Pinah, Lüderitz District, Namibia [j]; Nic. // B Hydrohetaerolite (brown and grey anisotropy, few brown internal reflections); Skorpion Mine, Rosh Pinah, Lüderitz District, Namibia [j]; Nic. +

622

Hydrohetaerolite A

120 μ

B

40 μ 623

Marokite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Mn oxide deposits pinkish to yellowish grey rare, carmine-red 15.96 - 18.66 Bireflectance: weak strong, pinkish to yellowish to brownish grey pinkish to yellowish grey


Mn3O4 Mn(Fe,Mn)2O4 (Fe,Mg)(Cr,Fe)2O4 ZnMn2O4 Zn2Mn4O8·(H2O) CaMn2O4 (Mg,Mn)2Sb0.5(Mn,Si,Ti)0.5O4 (Mn,Mg)4SbFeO8


Descriptions A Radial marokite (pinkish to yellowish grey pleochroism, bireflectance); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. // B Marokite (bluish to brownish grey anisotropy, carmine-red internal reflections); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. +

624

Marokite A

60 μ

B

60 μ 625

Minium (Red oxide of lead) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Pb deposits medium grey with orange tints from internal reflections bright orange-red [17] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/B.06-Trippkeite-Minium series IV/B.06-10 Trippkeite IV/B.06-15 Kusachiite IV/B.06-20 Schafarzikite IV/B.06-30 Versiliaite IV/B.06-40 Apuanite IV/B.06-50 Minium

CuAs2O4 CuBi2O4 FeSb2O4 Fe12Sb12O23S2 Fe5Sb4O12S Pb3O4

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 2/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Massive minium (medium grey with orange tint from internal reflections) replacing galena (dust-like, light grey); Revier Graben, Mezica (Miess), Slovenia [j]; Nic. // B Minium (bright orange internal reflections), galena (isotropic); Revier Graben, Mezica (Miess), Slovenia [j]; Nic. +

626

Minium A

60 μ

B

60 μ 627

Valentinite (Antimony Bloom) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Sb minerals medium grey with brownish tint yellow to brownish [15] Bireflectance:

very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.01-Claudetite-Valentinite series IV/C.01-10 Claudetite IV/C.01-20 Valentinite IV/C.01-30 Auroantimonate

As2O3 Sb2O3 AuSbO3

2/m 2/m 2/m 2/m ortho.

Descriptions A Valentinite (medium grey) as oxidation product of stibnite (light grey); Emirli, Turkey [c]; Nic. // B Valentinite (yellowish), stibnite (anisotropic); Emirli, Turkey [c]; Nic. +

628

Valentinite A

239 μ

B

239 μ 629

Bismite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Bi minerals medium grey white, yellow, green [12] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.02-Arsenolite-Sillenite series IV/C.02-10 Arsenolite IV/C.02-20 Senarmontite IV/C.02-30 Bismite IV/C.02-35 Sphaerobismoite IV/C.02-40 Sillenite IV/C.02-50 Chrombismite

A B C D E

As2O3 Sb2O3 Bi2O3 Bi2O3 Bi12SiO20 Bi16CrO27

– 4/m 3 2/m – 4/m 3 2/m 2/m tet. 23 tet.

Descriptions Bismite (medium grey, light brownish tint) replacing bismuthinite (light grey, cleavage and cracks); Schneeberg, Saxony, Germany [a]; Nic. // Colloform bismite (light grey) in quartz matrix (dark grey); Schneeberg, Saxony, Germany [c]; Nic. // Bismite (yellow internal reflections), quartz (colourless internal reflections); Schneeberg, Saxony, Germany [c]; Nic. + Bismite crystals (medium grey) and fine-grained native selenium (lightest grey); Nuestra Señora de la Luz, Leon, Guanajuato, Mexico [j]; Nic. // Bismite (green internal reflections), native selenium (dark red internal reflections); Nuestra Señora de la Luz, Leon, Guanajuato, Mexico [j]; Nic. +

630

Bismite A

120 μ

C

B

125 μ

125 μ

D

E

50 μ

50 μ 631

Bixbyite (Sitaparite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pneumatolytic, hydrothermal, metamorphic rocks medium grey 23.07 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.03-Bixbyite-Avicennite series IV/C.03-10 Bixbyite IV/C.03-20 Avicennite

(Mn,Fe)2O3 Tl2O3

– 2/m 3 – 2/m 3

Descriptions A Anhedral bixbyite (medium grey) twinning and/or exsolution of silicates (dark), part of the twins are replaced by fine Mn oxides (mottled darker grey); Otjosundu, South Africa [a]; Nic. / / B Bixbyite (dark) twinning and/or exsolution of silicates (bright streaks), part of the twins are replaced by fine Mn oxides (dark); Otjosundu, South Africa [a]; Nic. +

632

Bixbyite A

60 μ

B

60 μ 633

Corundum (Leucosapphire - colourless, Sapphire - blue, Ruby - red) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphic rocks bluish grey bright to dull blue [20-24] Bireflectance: distinct, grey shades

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.04-Hematite group IV/C.04-10 Corundum IV/C.04-20 Hematite IV/C.04-30 Eskolaite IV/C.04-40 Karelianite

Al2O3 Fe2O3 Cr2O3 V2O3

– 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Corundum (strong anisotropy despite prominent blue internal reflections, twins), pyrite (isotropic), silicates (white and greenish internal reflections); Chibiny, Kola Peninsula, Russia [h]; Nic. + B Subhedral corundum (bluish grey) intergrown with pyrrhotite (brownish) and pyrite (cream), silicate matrix (dark grey); Chibiny, Kola Peninsula, Russia [h]; Nic. // C Corundum (blue internal reflections), pyrrhotite (brownish grey), pyrite (isotropic), silicates (bright internal reflections); Chibiny, Kola Peninsula, Russia [h]; Nic. +

634

Corundum A

47 μ

C

B

72 μ

72 μ

635

Hematite (Kidney Ore, Martite, Specularite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic, hydrothermal, metamorphic, sedimentary light bluish grey deep blood-red 26 - 29.64 Bireflectance: distinct brownish greys


A B C D E


– 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions Large clusters of euhedral and twinned hematite (medium grey, bireflectance); Gamsberg, South Africa [c]; Nic. // Hematite (red internal reflections and anisotropy); Gamsberg, South Africa [c]; Nic. + Deformed hematite platelets (medium grey) in tiemannite (light grey); Eskaborner Berg, Tilkerode, Germany [g]; Nic. // Colloform hematite (bright red internal reflections, brownish grey anisotropy), goethite (bluish grey anisotropy, brown internal reflections); Hornhausen, Nassau, Germany [a]; Nic. + Euhedral hematite (lamellar light and dark brownish grey anisotropy, red internal reflections in matrix); Pretoria Iron Mines, South Africa [a]; Nic. +

636

Hematite A

43 μ

C

B

85 μ

94 μ

D

E

87 μ

108 μ 637

Eskolaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Cr-rich tremolite skarns, metaquartzites, chlorite veins, chondrite meteorites medium grey, internal reflections already visible blue-green 19.80 Bireflectance:



– 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Subhedral eskolaite (grey with greenish internal reflections, center) in matrix of loose guyanaite grains (medium grey); Merume Creek, Mazaruni River, Guyana [h]; Nic. // B Eskolaite (bright blue-green internal reflections), guyanaite (dull green); Merume Creek, Mazaruni River, Guyana [h]; Nic. +

638

Eskolaite A

16 μ

B

16 μ 639

Karelianite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sulfide-rich glacial boulders from high-grade metamorphic rocks (schists and quartzites) olive-grey 17.78 Bireflectance: reddish brown to greenish grey

weak



– 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Karelianite (medium olive grey), pyrrhotite (brownish tint), quartz (dark grey), sphalerite (almost bluish grey impression), chalcopyrite (yellow), pentlandite (light cream); Outokumpu Mine, Outokumpu, Finland [j]; Nic. // B Karelianite (dark greenish grey), pyrrhotite (brownish grey anisotropy), quartz (milky and multicolour internal reflections), sphalerite (isotropic, brown internal reflections), chalcopyrite (dark olive grey), pentlandite (greenish grey); Outokumpu Mine, Outokumpu, Finland [j]; Nic. + C Karelianite (medium olive grey), pyrrhotite (brownish tint), sphalerite (almost bluish grey impression), chalcopyrite (yellow), pentlandite (light cream), various silicates (dark grey); Outokumpu Mine, Outokumpu, Finland [j]; Nic. //

640

Karelianite A

24 μ

C

B

50 μ

50 μ

641

Geikielite (Whitmanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

carbonatites, kimberlites, serpentinised ultramafics, contact metamorphic magnesian limestones medium grey pink 15.20 - 11.76 Bireflectance: purplish greys, anisotropy masked by strong internal reflections

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.05-Ilmenite group, Geikilith-Brizziite series IV/C.05-05 Akimotoite (Mg,Fe)SiO3 IV/C.05-10 Geikielite MgTiO3 IV/C.05-20 Ilmenite FeTiO3 IV/C.05-30 Pyrophanite MnTiO3 IV/C.05-40 Ecandrewsite (Zn,Fe,Mn)TiO3 IV/C.05-50 Melanostibite Mn(Sb,Fe)O3 IV/C.05-60 Brizziite-III NaSbO3 IV/C.05-60 Brizziite-VII NaSbO3

– 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3

Descriptions A Anhedral geikielite (medium grey) intergrown with graphite (brownish, bireflectance), silicates (dark grey); Turnpike, Brimfield, Massachusetts, USA [j]; Nic. // B Geikielite (clear pink internal reflections), graphite (undulating bright cream and dark anisotropy), silicates (grey); Turnpike, Brimfield, Massachusetts, USA [j]; Nic. +

642

Geikielite A

120 μ

B

120 μ 643

Ilmenite

(Gregorite, Menaccanite, Paracolumbite, Titanic Iron Ore, Thuenite, Titanoferrite, Washingtonite)


accessory of igneous and metamorphic rocks, placers (black sand deposits) brownish tinted grey 18.05 - 19.85 Bireflectance: strong, grey shades

strong


A B C D

E

– 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3

Descriptions Exsolution of ilmenite (brownish grey) and hematite (light grey); undisclosed locality, Guinea [c]; Nic. // Triple junctions of ilmenite (grey with brownish tint, strong bireflectance, fine exsolution lamellae of hematite); Telnes, Norway [b]; Nic. // Triple junctions of ilmenite (slight brownish to bluish anisotropy); Telnes, Norway [b]; Nic. + Rim of ilmenite (brownish grey pleochroism) around rutile (lamellar twins, bluish to brownish grey pleochroism, bireflectance) in galena (light grey), silicates (dark grey); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // Ilmenite (greenish to bluish grey anisotropy), rutile (dark brown to greenish grey anisotropy, faint internal reflections), galena (isotropic, scratched), silicates (multicolour internal reflections); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. +

644

Ilmenite A

45 μ

C

B

125 μ

125 μ

D

E

51 μ

51 μ 645

Pyrophanite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Mn deposits, accessory in granites and amphibolites medium grey strong, orange to red 18.41 - 15.81 Bireflectance: slight greenish greys


A

B

C D E

– 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3

Descriptions Euhedral aggregate of pyrophanite (medium grey, slightly darker than alabandite below), pyrite and very fine marcasite (both white), chalcopyrite (yellow), rhodonite (dark grey); Hata Mine, Iwate, Japan [l]; Nic. // Pyrophanite (orange to red internal reflections, slight greyish anisotropy), alabandite (dark), pyrite (dark), marcasite (greenish specs), chalcopyrite (dark), rhodonite (pink internal reflections); Hata Mine, Iwate, Japan [l]; Nic. + Pyrophanite (strong red to brown internal reflections), rhodonite (pink internal reflections); Hata Mine, Iwate, Japan [l]; Nic. + Large subhedral pyrophanite (medium grey with slightly brighter twin lamellae); Noda-Tamagawa mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. // Pyrophanite(dark greenish grey with darker grey twin lamellae); Noda-Tamagawa mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. +

646

Pyrophanite A

60 μ

C

B

125 μ

71 μ

D

E

40 μ

40 μ 647

Maghemite (Maghaemite, Sosmanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

weathering, low-temperature oxidation of magnetite and titanomagnetite brownish grey 22.84 isotropic

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.06-Ilmenite group, Maghemite series IV/C.06-10 Maghemite

gamma-Fe2O3

23

Descriptions A Subhedral maghemite (brownish grey, center) with rim of magnetite (slightly darker than maghemite), tabular hematite (bluish grey), small chalcopyrite grains (yellow) in sphalerite (darker grey); Nananea, Chivatera, Mexico [f]; Nic. // B Maghemite and magnetite (both dark grey, slightly anisotropic), hematite (dark with red internal reflections), sphalerite (red brown internal reflections); Nananea, Chivatera, Mexico [f]; Nic. +

648

Maghemite A

60 μ

B

60 μ 649

Högbomite (Hogbomite, Taosite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Fe deposits dark grey few, brown 8.15 - 8.70 Bireflectance: not always distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.07-Högbomite-Mengxianminite series IV/C.07-10 Magnesiohögbomite-2N2S (Al,Fe,Fe,Mg,Ti,Zn)11O15(OH) IV/C.07-10 Magnesiohögbomite-2N3S (Mg,Fe)1.4Ti0.3Al4O8 IV/C.07-10 Magnesiohögbomite-6N6S (Mg,Fe)1.4Ti0.3Al4O8 IV/C.07-15 Zincohögbomite-2N2S (Zn,Fe)(2-2x)(Ti)xAl4O8 IV/C.07-17 Ferrohögbomite-2N2S (Fe,Zn,Mg,Al)6Al14(Ti,Fe)2 O30(OH)2 IV/C.07-20 Freudenbergite Na2Fe2Ti6O16 IV/C.07-30 Kamiokite Fe2Mo3O8 IV/C.07-40 Nolanite (V,Fe,Fe,Ti)10O14(OH)2 IV/C.07-42 Rinmanite (Zn,Mn)2Sb2Mg2Fe4O14(OH)2 IV/C.07-45 Magnesionigerite-2N1S (Mg,Zn,Fe,Al)4(Sn,Fe)2 Al10O22(OH)2 IV/C.07-45 Magnesionigerite-6N6S (Mg,Zn,Fe,Al)4(Sn,Fe)2 Al10O22(OH)2 IV/C.07-50 Ferronigerite-2N1S Zn,Mg,Fe)(Sn,Zn)2(Al,Fe)12O22(OH)2 IV/C.07-50 Ferronigerite-6N6S (Fe,Zn)4Sn2(Al,Fe)15 O30(OH)2 IV/C.07-60 Mengxianminite (Ca,Na)3(Fe,Mn)2Mg2(Sn,Zn)5Al8O29

6mm 6mm – 3 2/m 6mm 6mm 2/m 6mm 6mm 6mm – 3 2/m trig. – 3 2/m – 3 2/m ortho.

Descriptions A Högbomite plate (center, almost as dark grey as gang minerals) next to spinell (slightly darker), magnetite (lightest grey), ilmenite (brownish grey, bireflectance); Kastor, Vallatj Routivare, Sweden [e]; Nic. // B Högbomite (darkest grey, few brown internal reflections), magnetite (lighter grey, slightly anisotropic), ilmenite (brownish to greenish anisotropy); Kastor, Vallatj Routivare, Sweden [e]; Nic. +

650

Högbomite A

27 μ

B

27 μ 651

Magnetoplumbite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

skarns associated with metamorphosed Fe-Mn ores bluish tinted grey 22.17 - 23.67 Bireflectance: distinct, light bluish and medium grey to dark weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.08-Yimngite-Otjisumeite series IV/C.08-10 Yimengite IV/C.08-20 Hawthorneite IV/C.08-22 Haggertyite IV/C.08-25 Batiferrite IV/C.08-30 Hibonite IV/C.08-35 Nezilovite IV/C.08-40 Magnetoplumbite IV/C.08-45 Zenzenite IV/C.08-47 Lindqvistite IV/C.08-50 Plumboferrite IV/C.08-60 Bartelkeite IV/C.08-70 Otjisumeite

K(Cr,Ti,Fe,Mg)12O19 Ba[Ti3Cr4Fe4Mg]O19 Ba[Fe6Ti5Mg]O19 Ba(Ti2Fe8Fe2)O19 (Ca,Ce)(Al,Ti,Mg)12O19 PbZn2(Mn,Ti)2Fe8O19 Pb(Fe,Mn)12O19 Pb3(Fe,Mn)4Mn3O15 Pb2(Mn,Mg)Fe16027 Pb2Fe11-xMnxO19-2x PbFeGe3O8 PbGe4O9

6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m mono. tri.

Descriptions A Euhedral magnetoplumbite (light bluish tinted grey), partially intergrown with kentrolite (irregular, medium grey, slight bireflectance) in matrix of manganophyllite (Mn-biotite, dark grey); Långban, Filipstad, Värmland, Sweden [j]; Nic. // B Magnetoplumbite (light bluish and medium grey anisotropy, compare next photo), kentrolite (different grey shades anisotropy, red-brown internal reflections), manganophyllite (brown internal reflections); Långban, Filipstad, Värmland, Sweden [j]; Nic. + C Magnetoplumbite (dark to medium grey anisotropy, compare previous photo), kentrolite (different grey shades anisotropy, red-brown internal reflections), manganophyllite (brown internal reflections); Långban, Filipstad, Värmland, Sweden [j]; Nic. +

652

Magnetoplumbite A

20 μ

C

B

50 μ

50 μ

653

Plumboferrite (Ferro-Plumbite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Pb-bearing Fe-Mn ores medium grey with brownish tint 23.88 - 24.33 Bireflectance: brownish and bluish grey

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.08-Yimngite-Otjisumeite series IV/C.08-10 Yimengite IV/C.08-20 Hawthorneite IV/C.08-22 Haggertyite IV/C.08-25 Batiferrite IV/C.08-30 Hibonite IV/C.08-35 Nezilovite IV/C.08-40 Magnetoplumbite IV/C.08-45 Zenzenite IV/C.08-47 Lindqvistite IV/C.08-50 Plumboferrite IV/C.08-60 Bartelkeite IV/C.08-70 Otjisumeite

K(Cr,Ti,Fe,Mg)12O19 Ba[Ti3Cr4Fe4Mg]O19 Ba[Fe6Ti5Mg]O19 Ba(Ti2Fe8Fe2)O19 (Ca,Ce)(Al,Ti,Mg)12O19 PbZn2(Mn,Ti)2Fe8O19 Pb(Fe,Mn)12O19 Pb3(Fe,Mn)4Mn3O15 Pb2(Mn,Mg)Fe16027 Pb2Fe11-xMnxO19-2x PbFeGe3O8 PbGe4O9

6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m 6/m 2/m 2/m mono. tri.

Descriptions A Platy plumboferrite (medium grey), jacobsite (brownish grey), silicates (dark grey); Jakobsberg mine, Nordmark, Filipstad, Värmland, Sweden [j]; Nic. // B Plumboferrite (brownish and bluish grey anisotropy), jacobsite (dark brown), silicates (multicolour internal reflections); Jakobsberg mine, Nordmark, Filipstad, Värmland, Sweden [j]; Nic. + C Plumboferrite (dark brownish anisotropy, faint red-brown internal reflections), silicates (milky internal reflections); Jakobsberg mine, Nordmark, Filipstad, Värmland, Sweden [j]; Nic. +

654

Plumboferrite A

40 μ

C

B

83 μ

19 μ

655

Loveringite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late stage mineral from residual intercumulus magma of mafic intrusions bluish grey few, red-brown 16.50 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.09-Crichtonite group IV/C.09-10 Landauite IV/C.09-20 Mathiasite IV/C.09-30 Loveringite IV/C.09-40 Crichtonite IV/C.09-45 Dessauite IV/C.09-50 Lindsleyite IV/C.09-60 Davidite-(La) IV/C.09-62 Gramaccioliite-(Y) IV/C.09-70 Davidite-(Ce) IV/C.09-80 Senaite

NaMnZn2(Ti,Fe)6Ti12O38 (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 (Sr,Pb)(Y,U)(Ti,Fe)20O38 (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 (Ce,La)(Y,U)(Ti,Fe)20O38 Pb(Ti,Fe,Mn)21O38

– 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3

Descriptions A Subhedral loveringite (bluish grey) intergrown with pyrrhotite (light brown) and marcasite (cream), silicates (dark grey); Chibiny, Kola Peninsula, Russia [h]; Nic. // B Loveringite (black, few red-brown internal reflections), pyrrhotite (brownish grey), marcasite (dark patches), silicates (greyish internal reflections); Chibiny, Kola Peninsula, Russia [h]; Nic. +

656

Loveringite A

60 μ

B

60 μ 657

Davidite-(Ce, La, Y) (Ferutite, Mavidzite, Ufertite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

U-rich pegmatites medium grey mottled dark brown 16.96 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.09-Crichtonite group IV/C.09-10 Landauite IV/C.09-20 Mathiasite IV/C.09-30 Loveringite IV/C.09-40 Crichtonite IV/C.09-45 Dessauite IV/C.09-50 Lindsleyite IV/C.09-60 Davidite-(La) IV/C.09-62 Gramaccioliite-(Y) IV/C.09-70 Davidite-(Ce) IV/C.09-80 Senaite

NaMnZn2(Ti,Fe)6Ti12O38 (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 (Sr,Pb)(Y,U)(Ti,Fe)20O38 (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 (Ce,La)(Y,U)(Ti,Fe)20O38 Pb(Ti,Fe,Mn)21O38

– 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3 – 3

Descriptions A Anhedral davidite (medium grey), slightly darker than the surrounding large ilmenorutile crystal (medium grey); Bakers Trench, W of Broken Hill, New South Wales, Australia [j]; Nic. // B Anhedral davidite (medium grey, mottled), ilmenorutile (slightly lighter grey) and goethitehematite mixture (dirty brownish grey) as alteration products of ilmenorutile; Bakers Trench, W of Broken Hill, New South Wales, Australia [j]; Nic. // C Davidite (mottled dark brown internal reflections), ilmenorutile (dark brownish grey anisotropy, some brilliant internal reflections), hematite (strong red internal reflections); Bakers Trench, W of Broken Hill, New South Wales, Australia [j]; Nic. +

658

Davidite-(Ce, La, Y) A

120 μ

C

B

125 μ

125 μ

659

Perovskite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]:

chlorite, talc, serpentine rocks medium blue-grey pink to orange 16.31 Bireflectance: (15.6 niobian)

Anisotropy: Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.10-Perowskite series IV/C.10-10 Uhligite IV/C.10-20 Perovskite IV/C.10-30 Latrappite IV/C.10-40 Tausonite IV/C.10-50 Loparite-(Ce) IV/C.10-55 Isolueshite IV/C.10-60 Lueshite IV/C.10-70 Natroniobite IV/C.10-80 Macedonite

Ca3(Ti,Al,Zr)9O20 CaTiO3 (Ca,Na)(Nb,Ti,Fe)O3 SrTiO3 (Ce,Na,Ca)2(Ti,Nb)2O6 (Na,La,Ca)(Nb,Ti)O3 NaNbO3 NaNbO3 PbTiO3

cub. 2/m 2/m 2/m 2/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 222 mono. 4/m 2/m 2/m

Descriptions A Euhedral perovskite (medium blue-grey) and magnetite (brownish grey) in silicates (dark grey); Kopje 6, Kopjeskraal, Bushmanland, South Africa [j]; Nic. // B Perovskite (pink internal reflections), magnetite (isotropic), silicates (various internal reflections); Kopje 6, Kopjeskraal, Bushmanland, South Africa [j]; Nic. + C Perovskite (orange internal reflections), magnetite (isotropic), silicates (bright internal reflections); Unterwiesenthal, Erzgebirge, Saxony, Germany [j]; Nic. +

660

Perovskite A

60 μ

C

B

60 μ

125 μ

661

Macedonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

microcline-quartz syenite pegmatite veins medium grey yellow, brown, red, green 20.80 Bireflectance: very weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.10-Perowskite series IV/C.10-10 Uhligite IV/C.10-20 Perovskite IV/C.10-30 Latrappite IV/C.10-40 Tausonite IV/C.10-50 Loparite-(Ce) IV/C.10-55 Isolueshite IV/C.10-60 Lueshite IV/C.10-70 Natroniobite IV/C.10-80 Macedonite

Ca3(Ti,Al,Zr)9O20 CaTiO3 (Ca,Na)(Nb,Ti,Fe)O3 SrTiO3 (Ce,Na,Ca)2(Ti,Nb)2O6 (Na,La,Ca)(Nb,Ti)O3 NaNbO3 NaNbO3 PbTiO3

cub. 2/m 2/m 2/m 2/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 222 mono. 4/m 2/m 2/m

Descriptions A Individual grains of macedonite (medium grey); Crni Kamen, Prilep, Macedonia [j]; Nic. // B Macedonite (yellow, red, brown, and green internal reflections); Crni Kamen, Prilep, Macedonia [j]; Nic. +

662

Macedonite A

24 μ

B

24 μ 663

Stibiconite (Hydro-Cervantite, Stibiolite, Volgerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Sb-containing sulfides dark grey white, yellowish to light brown [7] Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.11-Stibiconite group, Partzite-Bindheimite series IV/C.11-10 Partzite Cu2Sb2(O,OH)7 IV/C.11-20 Stetefeldtite Ag2Sb2O6(O,OH) IV/C.11-30 Lewisite (Ca,Fe,Na)2(Sb,Ti)2O7 IV/C.11-40 Romeite (Ca,Fe,Mn,Na)2(Sb,Ti)2 O6(O,OH,F) IV/C.11-50 Stibiconite SbSb2O6(OH) IV/C.11-60 Bismutostibiconite Bi(Sb,Fe)2O7 IV/C.11-70 Bindheimite Pb2Sb2O6(O,OH)

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Fine-grained stibiconite (dark grey) replacing stibnite (light grey, bireflectance); Pha Had mine, Thailand [d]; Nic. // B Stibiconite (white to yellow internal reflections), stibnite (grey shades anisotropy); Pha Had mine, Thailand [d]; Nic. +

664

Stibiconite A

60 μ

B

60 μ 665

Bindheimite (Moffrasite, Monimolite, Stibiogalenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphism-related high grade/temperature Pb-Sb ores dark grey straw yellow [10] Bireflectance: strong isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.11-Stibiconite group, Partzite-Bindheimite series IV/C.11-10 Partzite Cu2Sb2(O,OH)7 IV/C.11-20 Stetefeldtite Ag2Sb2O6(O,OH) IV/C.11-30 Lewisite (Ca,Fe,Na)2(Sb,Ti)2O7 IV/C.11-40 Romeite (Ca,Fe,Mn,Na)2(Sb,Ti)2 O6(O,OH,F) IV/C.11-50 Stibiconite SbSb2O6(OH) IV/C.11-60 Bismutostibiconite Bi(Sb,Fe)2O7 IV/C.11-70 Bindheimite Pb2Sb2O6(O,OH)

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Fibrous bindheimite (medium grey shades, strong bireflectance); Pershing Co., Nevada, USA [c]; Nic. // B Bindheimite (pronounced yellow internal reflections mask grey anisotropy); Pershing Co., Nevada, USA [c]; Nic. +

666

Bindheimite A

120 μ

B

120 μ 667

Pyrochlore (Chalco-Lamprite, Endeiolite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

nepheline-syenite rocks medium grey bright, colourless 10.50 Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.17-Pyrochlore group, Pyrochlore series with Nb > Ti IV/C.17-10 Pyrochlore (Na,Ca)2Nb2O6(OH,F) IV/C.17-20 Calciobetafite Ca2(Ti,Nb)2(O,OH)7 IV/C.17-30 Kalipyrochlore (H2O,Sr)(Nb,Ti)(O,OH)6·(H2O,K) IV/C.17-40 Strontiopyrochlore Sr2Nb2(O,OH)7 IV/C.17-50 Bariopyrochlore (Ba,Sr)(Nb,Ti)2(O,OH)7 IV/C.17-60 Yttropyrochlore-(Y) (Y,Na,Ca,U)1-2(Nb,Ta,Ti)2(O,OH)7 IV/C.17-70 Ceriopyrochlore-(Ce) (Ce,Ca,Y)2(Nb,Ta)2O6(OH,F) IV/C.17-80 Plumbopyrochlore (Pb,Y,U,Ca)2-xNb2O6(OH) IV/C.17-85 Bismutopyrochlore (Bi,U,Ca,Pb)1+x(Nb,Ta)2 O6(OH)·nH2O IV/C.17-90 Uranpyrochlore (U,Ca,Ce)2(Nb,Ta)2O6(OH,F)

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 2/m 3 – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Pyrochlore (medium grey; bright internal reflections) in carbonate matrix (darker grey); Kombra Hill carbonatite, E of Isoka, NE Zambia [c]; Nic. // B Pyrochlore (colourless; bright internal reflections), carbonate matrix stained with Fe-hydroxides (brown); Kombra Hill carbonatite, E of Isoka, NE Zambia [c]; Nic. +

668

Pyrochlore A

32 μ

B

32 μ 669

Armalcolite (Kennedyite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Ti oxides associated with deep-seated intrusives medium grey 13.27 - 14.26 Bireflectance: strong, pale grey to dark bluish grey observed

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.24-Armalcolite-Arizonite series IV/C.24-10 Armalcolite IV/C.24-20 Pseudobrookite IV/C.24-30 Pseudorutile

A B C D E

(Mg,Fe)Ti2O5 (Fe,Fe)2(Ti,Fe)O5 Fe2Ti3O9

2/m 2/m 2/m 2/m 2/m 2/m 32

Descriptions Euhedral armalcolite (medium grey), silicate matrix (dark grey); Mateke Hills, SE Zimbabwe [j]; Nic. // Anhedral armalcolite (medium grey shades, fine exsolution lamellae), silicate matrix (dark grey); Mateke Hills, SE Zimbabwe [j]; Nic. // Armalcolite (dark greenish to brownish grey anisotropy), silicate matrix (multicolour and red internal reflections, the latter from finest hematite); Mateke Hills, SE Zimbabwe [j]; Nic. + Subhedral to euhedral armalcolite (medium grey), silicate matrix (dark grey); Mateke Hills, SE Zimbabwe [j]; Nic. // Armalcolite (bright brown internal reflections), silicate matrix (multicolour and red internal reflections, the latter from finest hematite); Mateke Hills, SE Zimbabwe [j]; Nic. +

670

Armalcolite A

24 μ

C

B

27 μ

69 μ

D

E

100 μ

100 μ 671

Pseudobrookite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic, post-volcanic blue-grey brown 17.67 - 18.32 Bireflectance: slightly greyish

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/C.24-Armalcolite-Arizonite series IV/C.24-10 Armalcolite IV/C.24-20 Pseudobrookite IV/C.24-30 Pseudorutile

(Mg,Fe)Ti2O5 (Fe,Fe)2(Ti,Fe)O5 Fe2Ti3O9

2/m 2/m 2/m 2/m 2/m 2/m 32

Descriptions A Pseudobrookite crystals (blue-grey) in olivine matrix (dark grey); Michelsberg Quarry, Katzenbuckel Mt., Eberbach, Odenwald, Baden-Württemberg, Germany [j]; Nic. // B Pseudobrookite (brown internal reflections, slight greyish anisotropy), olivine (yellow internal reflections); Michelsberg Quarry, Katzenbuckel Mt., Eberbach, Odenwald, Baden-Württemberg, Germany [j]; Nic. +

672

Pseudobrookite A

31 μ

B

31 μ 673

Quartz (various names according to colour) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, metamorphic, and igneous rocks dark grey clear, milky, brilliant (anomalous interference colours) [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.01-Quartz group IV/D.01-10 Quartz IV/D.01-20 Tridymite IV/D.01-30 Cristobalite IV/D.01-35 Moganite IV/D.01-40 Melanophlogite IV/D.01-40 Melanophlogite-beta IV/D.01-50 Coesite IV/D.01-60 Stishovite IV/D.01-70 Lechatelierite IV/D.01-80 Opal

SiO2 SiO2 SiO2 SiO2 SiO2·n(C,H,O,S) SiO2·n(C,H,O,S) SiO2 SiO2 SiO2 SiO2·nH2O

32 1 422 2/m 4/m 2/m 2/m – 4/m 3 2/m 2/m 4/m 2/m 2/m none none

Descriptions A Euhedral quartz (dark grey) in matrix of native bismuth (pinkish white, many scratches); Ludwig-Vereinigt-Feld Mine, Oelsnitz, Saxony, Germany [a]; Nic. // B Quartz (transparent and multicolour internal reflections), native bismuth (dark brownish, many scratches); Ludwig-Vereinigt-Feld Mine, Oelsnitz, Saxony, Germany [a]; Nic. +

674

Quartz A

120 μ

B

120 μ 675

Silica, amorphous (Common Opal) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal, submarine, surficial cap rocks dark grey clear to milky [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.01-Quartz group IV/D.01-10 Quartz IV/D.01-20 Tridymite IV/D.01-30 Cristobalite IV/D.01-35 Moganite IV/D.01-40 Melanophlogite IV/D.01-40 beta-Melanophlogite IV/D.01-50 Coesite IV/D.01-60 Stishovite IV/D.01-70 Lechatelierite IV/D.01-80 Opal

SiO2 SiO2 SiO2 SiO2 SiO2·n(C,H,O,S) SiO2·n(C,H,O,S) SiO2 SiO2 SiO2 SiO2·nH2O

32 1 422 2/m 4/m 2/m 2/m – 4/m 3 2/m 2/m 4/m 2/m 2/m none none

Descriptions A Colloform amorphous silica (dark grey, round aggregates) on sphalerite (medium grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // B Amorphous silica (white internal reflections), sphalerite (brown internal reflections); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

676

Silica, amorphous A

120 μ

B

120 μ 677

Rutile (Cajuelite, Edisonite, Gallitzinite, Sagenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

accessory in high-pressure and -temperature igneous rocks, detrital greys with bluish tint yellow, brown 19.87 - 23.27 Bireflectance: strong, greyish to dark greys with bluish tint

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.02-Rutile group, Rutile-Cassiterite-Platnerite series IV/D.02-10 Rutile TiO2 IV/D.02-20 Pyrolusite MnO2 IV/D.02-30 Squawcreekite (Fe,Sb,W)O4·H2O IV/D.02-40 Cassiterite SnO2 IV/D.02-45 Argutite GeO2 IV/D.02-50 Paratellurite TeO2 IV/D.02-60 Plattnerite PbO2

A B C D E

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 422 4/m 2/m 2/m

Descriptions Hypidiomorphic rutile (grey with bluish tint) intergrown with graphite; Kropfmühl, Germany [c]; Nic. // Polysynthetic rutile twins (greyish to dark anisotropy, brown internal reflections); Kropfmühl, Germany [c]; Nic. + Rutile twin (grey with bluish tint) with bireflectance; Kropfmühl, Germany [c]; Nic. // Sagenite (twinned rutile; medium grey); Cameroon [d]; Nic. // Rutile needles (strong yellow internal reflections), chalcopyrite (dark), pyrite (dark), silicate (dull internal reflections); Ludwigshoffnung mine, Hessia, Germany [d]; Nic. +

678

Rutile A

60 μ

C

B

63 μ

46 μ

D

E

59 μ

37 μ 679

Pyrolusite* (Calvonigrit, Wad) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, supergene cream with yellow tint 18.46 - 30.62 Bireflectance: strong, creme- to blue-grey

weak, yellow to yellow-grey



*(see also polianite for comparison)

Descriptions A Euhedral pyrolusite (cream, typical contraction cracks) and todorokite (grey fibres) in carbonate (dark); Smartt Mine, Hotazel, South Africa [c]; Nic. // B Pyrolusite (pleochroitic, cream), todorokite (pleochroitic, bluish grey); Smartt Mine, Hotazel, South Africa [c]; Nic. + C Euhedral pyrolusite (cream, cracks), goethite (bluish grey); Bergwerkswald, Lindener Mark, Giessen, Germany [a]; Nic. //

680

Pyrolusite* A

60 μ

C

B

125 μ

60 μ

681

Polianite* (Wad) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, hydrothermal, supergene yellowish, brownish, and bluish grey 18.46 - 30.62 Bireflectance: distinct grey, orange, brown, blue yellowish, brownish, and bluish grey



*Although already Ramdohr (1969) acknowledges the mineralogical and geochemical equality of polianite and pyrolusite (the former nowadays is generally considered an outdated name), both minerals show significant differences in their optical appearance and are, thus, shown individually.

A

B C

D E

Descriptions Polianite aggregate (twins with yellowish, brownish, and bluish grey pleochroism, bireflectance), quartz (dark grey); Restormel Royal Iron Mine (Trinity Mine), Lostwithiel, Cornwall, England, UK [j]; Nic. // Polianite (grey, orange, brown, and bluish anisotropy), quartz (multicolour internal reflections); Restormel Royal Iron Mine (Trinity Mine), Lostwithiel, Cornwall, England, UK [j]; Nic. + Large twins of polianite (orange grey, brown, and blue anisotropy), quartz (multicolour internal reflections); Restormel Royal Iron Mine (Trinity Mine), Lostwithiel, Cornwall, England, UK [j]; Nic. + Small cluster of polianite crystals (light grey) in goethite (dark grey); Stiepelmann’s Beryll Location, Kleine Spitzkopje, Namibia [j]; Nic. // Polianite (dark bluish grey), goethite (strong brown internal reflections), malachite (green internal reflections); Stiepelmann’s Beryll Location, Kleine Spitzkopje, Namibia [j]; Nic. +

682

Polianite* A

40 μ

C

B

83 μ

167 μ

D

E

50 μ

50 μ 683

Cassiterite (Stanniolite, Stannolite, Tin Ore, Wood Tin) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granites, pegmatites, alluvial placers medium grey white to brown 10.86 - 12 Bireflectance: strong to weak strong, greys


A

B C D E


Descriptions Cassiterite (medium grey) replaced by stannite (greenish grey), small specs of chalcopyrite (yellow), quartz (dark grey); Shensei Gang, Ashio mine, Ashio, Honshu Island, Japan [j]; Nic. / / Cassiterite concentrate (grey irregular twinned grains, bireflectance), columbite (upper left, slightly lighter grey than cassiterite); Kazat mine, Merqui, Burma [d]; Nic. // Cassiterite (anisotropy more pronounced), columbite (medium grey, small red to brown internal reflections); Kazat mine, Merqui, Burma [d]; Nic. + (+2°) Colloform cassiterite (internal reflections with various brown shades, grey anisotropy visible in dark layers); Dzhalindin deposit, Little Khingan Ridge, Far Eastern Region, USSR [j]; Nic. + “Wood tin” (finely laminated, various brown internal reflections, grey anisotropy); Clarisa, Maragua, Bolivia [c]; Nic. +

684

Cassiterite A

34 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 685

Plattnerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

weathered hydrothermal base-metal deposits in arid climates grey-white, with red-brown internal reflections faint, red-brown 16.78 - 17.18 Bireflectance: isotropic distinct



Descriptions A Irregular replacement of galena (light grey) by very fine-grained plattnerite (dark grey); Touissit, Oujda-Angad Province, Morocco [j]; Nic. // B Undulating laminae of extremely fine plattnerite (dark grey) with relict galena (light grey); Touissit, Oujda-Angad Province, Morocco [j]; Nic. //

686

Plattnerite A

120 μ

B

60 μ 687

Ilmenorutile (Rumongite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granite pegmatites, carbonatites, alluvial placers medium cream-grey brown [17] Bireflectance: weak strong to slight, dark grey

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.03-Rutile group, Ilmenorutile-Strüverite series IV/D.03-10 Ilmenorutile (Ti,Nb,Fe)O2 IV/D.03-20 Strüverite (Ti,Ta,Fe)O2

4/m 2/m 2/m 4/m 2/m 2/m

Descriptions A Massive ilmenorutile (grey, slight bireflectance) with rutile exsolution lamellae (brownish grey, bireflectance); Iveland, Aust-Agder, Norway [j]; Nic. // B Ilmenorutile (slight dark grey anisotropy, bright and brown internal reflections), rutile (here almost black lamellae); Iveland, Aust-Agder, Norway [j]; Nic. +

688

Ilmenorutile A

24 μ

B

40 μ 689

Tapiolite (Poly-Rutile, Skogbölite, Tammela-Tantalite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatites, alluvial medium greys faint, brown specs 15.95 - 17.00 Bireflectance: dark greys

weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.04-Tapiolite group IV/D.04-00 Tapiolite IV/D.04-10 Ferrotapiolite IV/D.04-20 Manganotapiolite IV/D.04-40 Bystromite IV/D.04-50 Tripuhyite IV/D.04-60 Ordonezite

(Fe,Mn)(Ta,Nb)2O6 (Fe,Mn)(Ta,Nb)2O6 (Mn,Fe)(Ta,Nb)2O6 MgSb2O6 FeSbO4 ZnSb2O6


Descriptions A Tapiolite (medium greys), wolframite matrix (brownish grey), arsenopyrite (white); Ehrenfriedersdorf, Germany [g]; Nic. // B Tapiolite (strong grey anisotropy, light brown internal reflections), wolframite (red-brown internal reflections, brown anisotropy); Ehrenfriedersdorf, Germany [g]; Nic. +

690

Tapiolite A

60 μ

B

60 μ 691

Cryptomelane Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Mn-bearing deposits medium grey brown (in fine grains) [25] Bireflectance: light to dark grey with brownish tint

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.08-Cryptomelane group IV/D.08-10 Manjiroite IV/D.08-20 Cryptomelane IV/D.08-25 Strontiomelane IV/D.08-30 Priderite IV/D.08-33 Henrymeyerite IV/D.08-35 Ankangite IV/D.08-40 Mannardite IV/D.08-50 Redledgeite IV/D.08-60 Hollandite IV/D.08-70 Coronadite IV/D.08-80 Cesarolite

A B C D E

(Na,K)(Mn,Mn)8O16·nH2O K(Mn,Mn)8O16 SrMn6Mn2O16 (K,Ba)(Ti,Fe)8O16 BaFeTi7O16 Ba(Ti,V,Cr)8O16 BaTi6V2O16·H2O BaTi6Cr2O16·H2O Ba(Mn,Mn)8O16 Pb(Mn,Mn)8O16 PbH2Mn3O8

4/m 2/m 2/m 4/m 4/m 4/m 4/m 4/m 2/m 2/m trig.

Descriptions Etremely fine-grained cryptomelane (medium grey) replacing country rock along cracks; Chiwefwe near Mkushi, Mwendafye Hills, Central Zambia [j]; Nic. // Colloform cryptomelane (medium grey) with radiating fibres in cavity; Chiwefwe near Mkushi, Mwendafye Hills, Central Zambia [j]; Nic. // Cryptomelane (light to dark grey with brownish tint); Chiwefwe near Mkushi, Mwendafye Hills, Central Zambia [j]; Nic. + Cryptomelane (fibrous, lightest grey) replaces groutite (large crystals, various grey shades, strong bireflectance); Sagamore Mine, Cuyuna Range, Minnesota, USA [j]; Nic. // Cryptomelane (bright and dark anisotropy), groutite (cream to brownish grey anisotropy, small brown internal reflections), fibrous; Sagamore Mine, Cuyuna Range, Minnesota, USA [j]; Nic. +

692

Cryptomelane A

60 μ

C

B

250 μ

250 μ

D

E

94 μ

94 μ 693

Hollandite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

contact metamorphic Mn ores medium greys 26.47 - 31.23 Bireflectance: strong, brownish tinted greys weak, grey shades

weak



4/m 2/m 2/m 4/m 4/m 4/m 4/m 4/m 2/m 2/m trig.

Descriptions A Large crystals of hollandite (grey shades, bireflectance) intergrown with pyrolusite (more yellowish, bireflectance), fine-grained Mn oxide matrix (medium grey); Gao, Mali [d]; Nic. // B Hollandite (anisotropy with tinted grey shades), pyrolusite (more obvious anisotropy); Gao, Mali [d]; Nic. + C Fibrous and massive hollandite (medium grey) partially replaced by pyrolusite (large crystals, cream shades, cracks); Nuba mountains, Kordofan, Sudan [d]; Nic. //

694

Hollandite A

120 μ

C

B

250 μ

80 μ

695

Coronadite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, hot springs, oxidation zone of Mn deposits and manganiferous sediments medium grey [35] Bireflectance: light to dark grey shades



4/m 2/m 2/m 4/m 4/m 4/m 4/m 4/m 2/m 2/m trig.

Descriptions A Coronadite laminae (medium grey) intergrown with goethite laminae (darker grey); Broken Hill, Australia [g]; Nic. // B Coronadite (different greys anisotropy), goethite (dark brown internal reflections); Broken Hill, Australia [g]; Nic. +

696

Coronadite A

103 μ

B

103 μ 697

Todorokite (Delatoreite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, deep sea nodules dark to medium grey 9.41 - 16.62 Bireflectance: distinct strong, dark to brownish grey to blue grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.09-Todorokite-Romanéchite series IV/D.09-10 Todorokite IV/D.09-20 Woodruffite IV/D.09-30 Romanéchite

(Na,Ca,K)2(Mn,Mn)6O12·3-4.5H2O (Zn,Mn)2Mn5O12·4H2O (Ba,H2O)2(Mn,Mn)5O10

2/m tet. 2/m

Descriptions A Fibrous todorokite (dark to medium grey, bireflectance) replacing calcite (dark); Smartt Mine, Hotazel, South Africa [c]; Nic. // B Todorokite (distinct anisotropy from dark to brownish grey to blue); Smartt Mine, Hotazel, South Africa [c]; Nic. +

698

Todorokite A

60 μ

B

60 μ 699

Woodruffite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised material from outcrop of orebody at Sterling Hill medium to brownish tinted grey [20] Bireflectance: dark brownish to bluish grey weak, medium to brownish tinted grey



2/m tet. 2/m

Descriptions A Very fine-grained mass of woodruffite (mottled medium grey) in contact with franklinite (slightly darker brownish grey); Sterling Mine, Sterling Hill, Ogdensburg, New Jersey, USA [j]; Nic. // B Woodruffite (specs of dark brownish to bluish grey anisotropy), franklinite (isotropic); Sterling Mine, Sterling Hill, Ogdensburg, New Jersey, USA [j]; Nic. +

700

Woodruffite A

60 μ

B

60 μ 701

Romanéchite (Psilomelane) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of Mn-bearing oxides, carbonates, and silicates medium bluish to brownish grey 22.22 - 28.99 Bireflectance: strong, cream to dark brown bluish to brownish grey

strong



2/m tet. 2/m

Descriptions A Subhedral elongated romanéchite (medium bluish to brownish grey) cross-cut by pyrolusite (slightly lighter, yellowish, contraction cracks); Hornhausen, Germany [a]; Nic. // B Romanéchite (cream to dark brown anisotropy), pyrolusite (spotty anisotropy, similar colours); Hornhausen, Germany [a]; Nic. +

702

Romanéchite A

60 μ

B

60 μ 703

Ramsdellite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Mn oxide deposits grey to greenish grey [14 - 17] Bireflectance: strong, green to brown grey to greenish grey

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.10-Ramsdellite-Vernadite series IV/D.10-10 Ramsdellite IV/D.10-15 Akhtenskite IV/D.10-20 Nsutite IV/D.10-30 Vernadite

MnO2 MnO2 (Mn1-x)(Mnx)(O2-2x)(OH2x) (Mn+,Fe,Ca,Na)(O,OH)2·nH2O

2/m 2/m 2/m 6/m 2/m 2/m hex. 4/m

Descriptions A Large radiating ramsdellite crystals (strong bireflectance and pleochroism, grey to greenish grey; pyrolusite would be more yellowish); Mina La Santiagueña, prov. Santiago del Estero, Argentina [f]; Nic. // B Ramsdellite (green to brown anisotropy; pyrolusite would be more bluish); Mina La Santiagueña, prov. Santiago del Estero, Argentina [f]; Nic. +

704

Ramsdellite A

239 μ

B

239 μ 705

Nsutite (Wad, Yokosukaite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

supergene alteration product of manganiferous carbonates medium greys with brownish tints [25 - 35] Bireflectance: distinct distinct, light to dark brownish grey greyish white with a creamy tint to bluish grey-white

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.10-Ramsdellite-Vernadite series IV/D.10-10 Ramsdellite IV/D.10-15 Akhtenskite IV/D.10-20 Nsutite IV/D.10-30 Vernadite

MnO2 MnO2 (Mn1-x)(Mnx)(O2-2x)(OH2x) (Mn+,Fe,Ca,Na)(O,OH)2·nH2O

Descriptions A Massive nsutite (mottled medium greys, bireflectance); Nsuta, Ghana [a]; Nic. // B Nsutite (light to dark brownish greys anisotropy); Nsuta, Ghana [a]; Nic. +

706

2/m 2/m 2/m 6/m 2/m 2/m hex. 4/m

Nsutite A

24 μ

B

24 μ 707

Anatase (Octahedrite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alpine gangue mineralisations, alteration product of Ti minerals, detrital bluish grey light yellow to brown, rarely blue 19.11 - 18.67 Bireflectance: weak

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.14-Anatase-Downeyite series IV/D.14-10 Anatase IV/D.14-20 Downeyite

A B C D

E F

TiO2 SeO2

4/m 2/m 2/m 4/m 2/m 2/m

Descriptions Mass of subhedral anatase (grey with bluish tint) next to ilmenite (brownish grey), chalcopyrite (yellow), pyrite (cream), silicates (darker grey); North Mine, Broken Hill, Australia [j]; Nic. // Anatase (bright internal reflections), ilmenite (dark), chalcopyrite (dark olive grey), pyrite (isotropic), silicates (white internal reflections); North Mine, Broken Hill, Australia [j]; Nic. + Rim of anatase (grey with bluish tint) around ilmenite (brownish grey, diagonal twin lamella slightly brighter), rhodonite (darker grey); North Mine, Broken Hill, Australia [j]; Nic. // Anatase (bright internal reflections), ilmenite (dark), chalcopyrite (dark olive grey), pyrite (isotropic), rhodonite (reddish brown internal reflections); North Mine, Broken Hill, Australia [j]; Nic. + Filigrane replacement of ilmenite or titanomagnetite by anatase (light grey needles), framboidal pyrite (cream), silicates (darker grey); Zirovski Mine, Todraz, Slovenia [j]; Nic. // Anatase (light cream internal reflections), pyrite (isotropic), silicates (whitish internal reflections); Zirovski Mine, Todraz, Slovenia [j]; Nic. +

708

Anatase A

B

125 μ

125 μ

D

C

167 μ

167 μ

F

E

23 μ

23 μ

709

Wolframite (see also Ferberite, Hübnerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins, greisens, granite pegmatites, alluvial deposits medium greys relatively rare, brown 14.7 - 16.4 Bireflectance: weak greenish grey to brown weak, grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.16-Wolframite series IV/D.16-00 Wolframite IV/D.16-10 Hübnerite IV/D.16-20 Ferberite IV/D.16-30 Sanmartinite IV/D.16-40 Wolframoixiolite

(Fe,Mn)WO4 MnWO4 FeWO4 (Zn,Fe)WO4 (Fe,Mn,Nb)(Nb,W,Ta)O4

2/m 2/m 2/m 2/m m

Descriptions A Subhedral wolframite grains (medium grey, slight bireflectance) in quartz (dark grey), small breakouts during sample preparation are common in wolframite; Horni Slavkov, Czech Republic [b]; Nic. // B Wolframite (greenish grey to brown anisotropy); Horni Slavkov, Czech Republic [b]; Nic. + C Wolframite (few red-brown internal reflections); Horni Slavkov, Czech Republic [b]; Nic. +

710

Wolframite A

120 μ

C

B

250 μ

42 μ

711

Hübnerite (Huebnerite, Mangano-Wolframite, Megabasite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins, greisens, granite pegmatites, alluvial medium grey, internal reflections visible red-brown to brilliant 13.66 - 16.26 Bireflectance: distinct, dark brown to black weak, greyish



2/m 2/m 2/m 2/m m

Descriptions A Large columnar hübnerite (medium grey with some brownish internal reflections); Pasto Bueno, Peru [a]; Nic. // B Hübnerite (brown to brilliant internal reflections); Pasto Bueno, Peru [a]; Nic. +

712

Hübnerite A

120 μ

B

120 μ 713

Ferberite (Fe-Wolframite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high-temperature hydrothermal veins, greisens, granitic pegmatites, alluvial and eluvial deposits brownish grey few (red-brown) to none 15.80 - 18.60 Bireflectance: weak distinct, brown shades



2/m 2/m 2/m 2/m m

Descriptions A Euhedral ferberite (brownish grey), arsenopyrite (slight yellow tint), tapiolite (medium greys, bireflectance, center), quartz (dark grey); Ehrenfriedersdorf, Germany [g]; Nic. // B Ferberite (various brown shades anisotropy), arsenopyrite (orange brown anisotropy), tapiolite (dark greys anisotropy), quartz (white internal reflections); Ehrenfriedersdorf, Germany [g]; Nic. +

714

Ferberite A

239 μ

B

239 μ 715

Ferrocolumbite (Coltan, Columbite, Dianite, Niobite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatites, alluvial deposits grey with brownish or pinkish tint yellow to brown 16.70 - 17.20 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.18-Columbite series IV/D.18-10 Magnesiocolumbite IV/D.18-20 Manganocolumbite IV/D.18-30 Ferrocolumbite IV/D.18-35 Magnesiotantalite IV/D.18-40 Manganotantalite IV/D.18-50 Ferrotantalite

A B C D E

(Mg,Fe,Mn)(Nb,Ta)2O6 (Mn,Fe)(Nb,Ta)2O6 FeNb2O6 (Mg,Fe)(Ta,Nb)2O6 MnTa2O6 FeTa2O6


Descriptions Regular intergrowth of ferrocolumbite (lighter grey) and cassiterite (medium grey); Kazat mine, Merqui, Burma [d]; Nic. // Subhedral ferrocolumbite (pinkish grey) intergrown with magnetite (also pinkish grey but lighter) and goethite (bluish grey); Djoume, Poli, Cameroon [d]; Nic. // Ferrocolumbite (yellow to brown internal reflections), magnetite (dark), goethite (orange internal reflections); Djoume, Poli, Cameroon [d]; Nic. + Large euhedral ferrocolumbite (pronounced anisotropy, red to brown internal reflections); Hagendorf, Germany [f]; Nic. + Oriented intergrowth of large ferrocolumbite (medium grey with brown tint), rutile (slightly lighter grey), and silicates (darker grey, also filling fine cracks); Mina La Bella, Concepción, Bolivia [c]; Nic. //

716

Ferrocolumbite A

60 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 717

Ferrotantalite (Coltan, Ildefonsite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granite pegmatites brownish grey few, red-brown on edges and along cracks [14] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.18-Columbite series IV/D.18-10 Magnesiocolumbite IV/D.18-20 Manganocolumbite IV/D.18-30 Ferrocolumbite IV/D.18-35 Magnesiotantalite IV/D.18-40 Manganotantalite IV/D.18-50 Ferrotantalite

(Mg,Fe,Mn)(Nb,Ta)2O6 (Mn,Fe)(Nb,Ta)2O6 FeNb2O6 (Mg,Fe)(Ta,Nb)2O6 MnTa2O6 FeTa2O6


Descriptions A Ferrotantalite (medium grey) with beginning oxidation along cracks; Uis, Gobabis, Namibia [c]; Nic. // B Large ferrotantalite grain (medium grey) with alteration on cracks and along grain boundary (slightly darker); Spargoville, Australia [d]; Nic. // C Ferrotantalite (dark with internal reflections); Spargoville, Australia [d]; Nic. +

718

Ferrotantalite A

60 μ

C

B

125 μ

125 μ

719

Brannerite (Cordobaite, Lodochnikite, Lodochnikovite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Au placers medium grey with brownish tint brown 11.96 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.22-Thorutite-Orthobrannerite series IV/D.22-10 Thorutite IV/D.22-20 Brannerite IV/D.22-30 Orthobrannerite

(Th,U,Ca)Ti2(O,OH)6 (U,Ca,Ce)(Ti,Fe)2O6 U2Ti4O12(OH)2

2/m 2/m 222

Descriptions A Mottled patch of brannerite (medium grey with slight brownish tint) intergrown with rutile (slightly brighter grey) next to rutile lamellae replacing ilmenite; Blind River, Canada [b]; Nic. // B Anhedral brannerite (medium grey with slight brownish tint) replacing rutile (slightly brighter grey); Blind River, Canada [b]; Nic. // C Brannerite (brownish internal reflections), rutile (colourless internal reflections); Blind River, Canada [b]; Nic. +

720

Brannerite A

60 μ

C

B

25 μ

25 μ

721

Foordite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granites medium brownish grey strong, red-brown [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.29-Badleyite-Uraninite series, Foordite-Thoreaulite IV/D.29-10 Foordite Sn(Nb,Ta)2O6 IV/D.29-20 Thoreaulite SnTa2O6

2/m 2/m

Descriptions A Irregular intergrowth (replacement?) of foordite (medium brownish grey) and thoreaulite (lightest grey), 2 unidentified replacement minerals at suture between the major phases (darker greys); Kubitaka, Punia, Kivu, Congo [j]; Nic. // B Foordite (red-brown internal reflections), thoreaulite (yellow brown internal reflections), unidentified minerals (white internal reflections and dark); Kubitaka, Punia, Kivu, Congo [j]; Nic. +

722

Foordite A

120 μ

B

120 μ 723

Thoreaulite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy:

secondary mineral in cassiterite-bearing rocks grey with brownish tint strong, yellow, orange, red, brown [19] Bireflectance: greenish grey to dark, anisotropy masked by strong internal reflections

Pleochroism: Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.29-Badleyite-Uraninite series, Foordite-Thoreaulite IV/D.29-10 Foordite Sn(Nb,Ta)2O6 IV/D.29-20 Thoreaulite SnTa2O6

A B C D E

2/m 2/m

Descriptions Large subhedral grains of thoreaulite (medium grey) with cleavage-controlled replacement by unidentified mineral (medium grey); Kubitaka, Punia, Kivu, Congo [j]; Nic. // Thoreaulite (strong brown internal reflections, darkest position of distinctive anisotropy, compare next photo); Kubitaka, Punia, Kivu, Congo [j]; Nic. + Thoreaulite (strong brown internal reflections, lightest position of distinctive greenish anisotropy, compare previous photo); Kubitaka, Punia, Kivu, Congo [j]; Nic. + Large clear thoreaulite (brown internal reflections) with inclusion of radial aggregate of unknown mineral (rutile?); Kubitaka, Punia, Kivu, Congo [j]; Nic. + Large subhedral thoreaulite (yellow to brown internal reflections, distinctive cleavage) with oriented needles of an unidentified mineral (dark); Kubitaka, Punia, Kivu, Congo [j]; Nic. +

724

Thoreaulite A

120 μ

C

B

250 μ

250 μ

D

E

125 μ

125 μ 725

Baddeleyite (Brazilite, Reitingerite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high temperature veins, gem placers dark grey brown to multi-colour [4] Bireflectance: greyish brown to almost black

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.31-Baddeleyite-Uraninite series IV/D.31-10 Baddeleyite IV/D.31-20 Tazheranite IV/D.31-30 Calzirtite IV/D.31-35 Hiarneite IV/D.31-40 Cerianite-(Ce) IV/D.31-50 Thorianite IV/D.31-60 Uraninite

ZrO2 CaTiZr2O8 CaZr3TiO9 (Ca,Mn,Na)2(Zr,Mn)5(Sb,Ti,Fe)2O16 (Ce+,Th)O2 ThO2 UO2

2/m – 4/m 3 2/m 2/m 2/m 2/m 4/m 2/m 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m

Descriptions A Single grain of baddeleyite (dark grey); Palabora, South Africa [d]; Nic. // B Baddeleyite (brown to multicolour internal reflections, twinning); Palabora, South Africa [d]; Nic. + (+2°)

726

Baddeleyite A

51 μ

B

51 μ 727

Uraninite (Kirchite, Pitch Blende, Ulrichite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

granite and syenite pegmatites, high-temperature hydrothermal veins, quartz conglomerates medium grey with brownish tint rare, occasionally dark brown 15.85 Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.31-Baddeleyite-Uraninite series IV/D.31-10 Baddeleyite IV/D.31-20 Tazheranite IV/D.31-30 Calzirtite IV/D.31-35 Hiarneite IV/D.31-40 Cerianite-(Ce) IV/D.31-50 Thorianite IV/D.31-60 Uraninite



Descriptions A Rounded uraninite grains (medium grey) in matrix of thucholite (slightly brownish tinted medium grey) next to native gold (yellow) and pyrite (creamish white); Elsburg mine, South-Africa [b]; Nic. // B Botryoidal uraninite (medium grey, prominent desiccation cracks) replaced by galena (light grey), carbonate (dark grey); Himmelsfürst Mine, Freiberg, Germany [g]; Nic. // C Euhedral uraninite (medium grey, many cracks) in vaesite (light grey); Shinkolobwe Mine, Shaba, Congo [j]; Nic. //

728

Uraninite A

60 μ

C

B

125 μ

167 μ

729

Thucholite† Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

cement of clastic (metamorphosed) sediments brownish tinted medium greys [14 - 17] Bireflectance: strong, grey shades brownish tinted medium greys

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/D.31-Baddeleyite-Uraninite series IV/D.31-10 Baddeleyite IV/D.31-20 Tazheranite IV/D.31-30 Calzirtite IV/D.31-35 Hiarneite IV/D.31-40 Cerianite-(Ce) IV/D.31-50 Thorianite IV/D.31-60 Uraninite †mixture



of uraninite, hydrocarbons, and some sulfides; name derives from components: Th-U-C-H-O

Descriptions A Anhedral thucholite (slightly brownish tinted medium grey, bireflectance) cementing uraninite (medium grey, rounded grains) and pyrite (creamish white); also containing irregular gold grains (yellow); Elsburg mine, South-Africa [b]; Nic. // B Thucholite (strong anisotropy, grey shades), uraninite (black), pyrite (dark, but lighter than uraninite); Elsburg mine, South-Africa [b]; Nic. +

730

Thucholite† A

60 μ

B

60 μ 731

Molybdite (Mo-ochre) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of Mo ores dark olive grey to brown [10] Bireflectance: strong, olive to brown olive grey shades

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/E.03-Molybdite-Ilsemannite series IV/E.03-10 Molybdite IV/E.03-20 Sidwillite IV/E.03-30 Ilsemannite IV/E.03-40 Bamfordite

MoO3 MoO3·2H2O Mo3O8·nH2O FeMo2O6(OH)3·H2O

2/m 2/m 2/m 2/m none tri.

Descriptions A Molybdite (strong olive to brown anisotropy), molybdenite (bluish greys anisotropy); Kasa Divrigi mine, Divrik, Turkey [b]; Nic. + B Lamellar molybdite (olive, very strong bireflectance, compare next photo) replacing molybdenite (light grey, strong bireflectance); Kasa Divrigi mine, Divrik, Turkey [b]; Nic. // C Molybdite (olive, very strong bireflectance, compare previous photo), molybdenite (light grey, strong bireflectance); Kasa Divrigi mine, Divrik, Turkey [b]; Nic. //

732

Molybdite A

24 μ

C

B

50 μ

50 μ

733

Pyrochroite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphic deposits, alteration product of hausmannite dark brownish grey reddish brown to brilliant [7] Bireflectance: strong, light to dark

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.03-Brucite series IV/F.03-10 Brucite IV/F.03-20 Amakinite IV/F.03-30 Pyrochroite IV/F.03-40 Theophrastite IV/F.03-50 Paraotwayite IV/F.03-60 Sweetite IV/F.03-70 Ashoverite IV/F.03-80 Wulfingite IV/F.03-90 Spertiniite IV/F.03-100 Portlandite

Mg(OH)2 (Fe,Mg)(OH)2 Mn(OH)2 Ni(OH)2 Ni(OH)2-x(SO4,CO3)0.5x Zn(OH)2 Zn(OH)2 Zn(OH)2 Cu(OH)2 Ca(OH)2

– 3 2/m – 3 2/m – 3 2/m – 3 2/m m 422 4/m 2/m 2/m 222 mm2 – 3 2/m

Descriptions A Tabular pyrochroite (cut perpendicular; medium grey) with partial oxidation on cleavages and cracks, associated with hausmannite; Långban, Sweden [c]; Nic. // B Pyrochroite (reddish brown to brilliant internal reflections); Långban, Sweden [c]; Nic. + C Pyrochroite (same as before, but now showing strong anisotropy); Långban, Sweden [c]; Nic. +

734

Pyrochroite A

60 μ

C

B

125 μ

125 μ

735

Goethite

(Acicular Iron Ore, Limonite, Needle Ironstone, Pyrosiderite, Pyrrhosiderite, Xanthosiderite)


Fe deposits, iron cap of sulfides deposits grey with bluish tint yellow, red, brown 12.67 - 13.87 Bireflectance: distinct, bluish greys yellow or colourless brownish yellow or yellow orange

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.06-Diaspore-Goethite-Feitknechtite series IV/F.06-10 Diaspore AlO(OH) IV/F.06-20 Boehmite AlO(OH) IV/F.06-25 Tsumgallite GaO(OH) IV/F.06-30 Goethite FeO(OH) IV/F.06-40 Lepidocrocite FeO(OH) IV/F.06-50 Akaganeite Fe(O,OH,Cl) IV/F.06-60 Feroxyhyte FeO(OH) IV/F.06-70 Manganite MnO(OH) IV/F.06-80 Groutite MnO(OH) IV/F.06-90 Feitknechtite beta-MnO(OH)

A B C D E

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m hex. 2/m 2/m 2/m 2/m hex.

Descriptions Sub-hedral goethite (medium grey), chalcocite (blue-grey), covellite (blue), bornite (pinkish brown), chalcopyrite (yellow); Otjozonjati Mine, Namibia [c]; Nic. // Goethite needles (medium grey) in cavity); Onganja Mine, Namibia [a]; Nic. // Goethite (strong yellow internal reflections); Onganja Mine, Namibia [a]; Nic. + Colloform goethite (bluish to brownish grey, bireflectance); Thuringia, Germany [a]; Nic. // Goethite (bluish grey anisotropy, brown internal reflections); Thuringia, Germany [a]; Nic. +

736

Goethite A

120 μ

C

B

25 μ

25 μ

D

E

125 μ

125 μ 737

Lepidocrocite (Ruby Iron, Ruby Mica) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Fe deposits medium grey red, especially in fine platelets 10.66 - 15.87 Bireflectance:

strong, difficult to see in fine platelets relatively strong, darker and lighter bluish grey shades distinct, not always detectable in fine crystals



Descriptions A Laths of lepidocrocite (medium grey) in part replaced by magnetite (slightly darker irregular patches); Kutlular, N Turkey [c]; Nic. // B Lepidocrocite (darker and lighter bluish grey shades anisotropy, small spots of red internal reflections); Kutlular, N Turkey [c]; Nic. + C Lepidocrocite (red internal reflections), silicate (bright internal reflections); unknown locality [a]; Nic. +

738

Lepidocrocite A

120 μ

C

B

75 μ

62 μ

739

Manganite (Brown Manganese Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

low-temperature hydrothermal, hot-spring Mn deposits medium grey with brownish tint blood-red 16.41 - 21.02 Bireflectance: distinct, grey shades distinct, brown to bluish bluish to brownish


A B C D E


Descriptions Manganite (medium grey) partially replaced by pyrolusite (light grey, contraction cracks); unknown locality [a]; Nic. // Large subhedral manganite (medium greys, bluish to brownish pleochroism) slightly replaced by pyrolusite (light cream); Ilfeld, Germany [c]; Nic. // Manganite (brown to bluish anisotropy, brown internal reflections), pyrolusite (difficult to discern here); Ilfeld, Germany [c]; Nic. + Massive manganite (medium grey, bireflectance colours from bluish to brownish); unknown locality [a]; Nic. // Manganite (strong brown to bluish anisotropy); unknown locality [a]; Nic. +

740

Manganite A

60 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 741

Groutite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

weathered banded iron formations, hydrothermally influenced Mn oxide deposits greys brown (relatively rare) 12.7 - 18.66 Bireflectance: strong cream to brownish grey grey to brownish



Descriptions A Well-crystallised groutite (various grey shades, strong bireflectance); Sagamore Mine, Cuyuna Range, Minnesota, USA [j]; Nic. // B Groutite (cream to brownish grey anisotropy, brown internal reflections); Sagamore Mine, Cuyuna Range, Minnesota, USA [j]; Nic. +

742

Groutite A

60 μ

B

60 μ 743

Feitknechtite (Hydrohausmannite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of Mn ores dull grey [15] Bireflectance: bluish grey shades



Descriptions A Hexagonal platelets of feitknechtite (dull grey), unidentified alteration products (slightly darker, colloform); Långban, Filipstad, Värmland, Sweden [j]; Nic. // B Feitknechtite (dull grey), unidentified alteration products (slightly darker, colloform); Långban, Filipstad, Värmland, Sweden [j]; Nic. // C Feitknechtite (slight bluish grey anisotropy), alteration products (brown internal reflections), there are some indications that minute brown internal reflections also belong to feitknechtite; Långban, Filipstad, Värmland, Sweden [j]; Nic. +

744

Feitknechtite A

24 μ

C

B

66 μ

66 μ

745

Lithiophorite (Allophytin) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zones of hydrothermal and sedimentary deposits brownish to bluish grey 9.46 - 19.07 Bireflectance: distinct extreme, light grey to dark brown to bluish grey strong, brownish to bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.07-Lithiophorite-Grimaldiite series IV/F.07-10 Lithiophorite IV/F.07-20 Asbolane IV/F.07-30 Heterogenite-2H IV/F.07-40 Heterogenite-3R IV/F.07-50 Bracewellite IV/F.07-60 Guyanaite IV/F.07-70 Grimaldiite

(Al,Li)MnO2(OH)2 (Co,Ni)1-y(MnO2)2-x(OH)2-2y+2x·nH2O CoO(OH) CoO(OH) CrO(OH) CrO(OH) CrO(OH)

– 3 2/m hex. 6/m 2/m 2/m – 3 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 3 2/m

Descriptions A Irregular mass of fine- and coarser-grained lithiophorite (distinct bireflectance, brownish to bluish grey pleochroism); Greifenbachmühle, Ehrenfriedersdorf, Germany [m]; Nic. // B Lithiophorite (brownish to bluish anisotropy); Greifenbachmühle, Ehrenfriedersdorf, Germany [m]; Nic. + C Layer of fine-grained lithiophorite (here only slight bireflectance, brownish to bluish grey pleochroism) next to massive pyrolusite (lighter grey); Greifenbachmühle, Ehrenfriedersdorf, Germany [m]; Nic. //

746

Lithiophorite A

60 μ

C

B

125 μ

125 μ

747

Heterogenite (Boodtite, Mindigite, Stainierite, Transvaalite, Trieuite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

residual soils above ultramafic rocks, oxidation product of smaltite and linneite brownish grey 16.7 - 25.47 Bireflectance: distinct, grey shades

slight to strong




Descriptions A Recrystallised heterogenite (brownish greys, pronounced bireflectance); Fungurume, Congo [d]; Nic. // B Heterogenite (various grey shades anisotropy), carbonates (bluish and white internal reflections), goethite (brown internal reflections); Fungurume, Congo [d]; Nic. +

748

Heterogenite A

24 μ

B

60 μ 749

Guyanaite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Merume Creek river sediments medium grey with greenish tint green [17] Bireflectance:




Descriptions A Subhedral guyanaite grains (medium grey with greenish tint); Merume Creek, Mazaruni River, Guyana [h]; Nic. // B Guyanaite (green internal reflections); Merume Creek, Mazaruni River, Guyana [h]; Nic. +

750

Guyanaite A

16 μ

B

16 μ 751

Chalcophanite (Hydrofranklinite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Zn-Mn-rich base metal deposits grey shades deep red 9.30 - 26.02 Bireflectance: distinct very strong strong, light grey to bluish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.11-Jiansuiite-Birnessite series IV/F.11-05 Jianshuiite IV/F.11-10 Aurorite IV/F.11-15 Ernienickelite IV/F.11-20 Chalcophanite IV/F.11-25 Cianciulliite IV/F.11-30 Birnessite

(Mg,Mn)Mn3O7·3H2O (Mn,Ag,Ca)Mn3O7·3H2O NiMn3O7·3H2O (Zn,Fe,Mn)Mn3O7·3H2O Mn(Mg,Mn)2Zn2(OH)10·2-4H2O (Na,Ca,K)x(Mn,Mn)2O4·1.5H2O

trig. – 1 trig. – 3 2/m 2/m

Descriptions A Radial aggregates of chalcophanite (bluish to darker grey, strong bireflectance), colloform hetaerolite (grey with brownish tint), hemimorphite (dark elongated needles); Broken Hill, Australia [c]; Nic. // B Chalcophanite (light bluish to darker grey anisotropy, very faint red internal reflections), hetaerolite (red internal reflections), hemimorphite (colourless internal reflections); Broken Hill, Australia [c]; Nic. +

752

Chalcophanite A

45 μ

B

45 μ 753

Birnessite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration product of Mn oxide precursors, desert varnish, telethermal hydrothermal, deep sea Mn nodules dark grey brown [10] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.11-Jiansuiite-Birnessite series IV/F.11-05 Jianshuiite IV/F.11-10 Aurorite IV/F.11-15 Ernienickelite IV/F.11-20 Chalcophanite IV/F.11-25 Cianciulliite IV/F.11-30 Birnessite

A B C D E

(Mg,Mn)Mn3O7·3H2O (Mn,Ag,Ca)Mn3O7·3H2O NiMn3O7·3H2O (Zn,Fe,Mn)Mn3O7·3H2O Mn(Mg,Mn)2Zn2(OH)10·2-4H2O (Na,Ca,K)x(Mn,Mn)2O4·1.5H2O

trig. – 1 trig. – 3 2/m 2/m

Descriptions Fine-grained laminated to radially crystallised birnessite (medium grey) in carbonate matrix (darker); Kangaroo Island, Australia [c]; Nic. // Birnessite laminae (lighter grey fibres) intergrown with unidentified massive Mn oxide (medium grey); Kangaroo Island [c]; Nic. // Birnessite (brown internal reflections), massive Mn oxide (dark layers); Kangaroo Island [c]; Nic. + Sheet-like birnessite (medium grey) grading into massive layer of unidentified Mn oxide (medium grey); Kangaroo Island [c]; Nic. // Birnessite (brown internal reflections); Kangaroo Island [c]; Nic. +

754

Birnessite A

120 μ

C

B

250 μ

250 μ

D

E

84 μ

84 μ 755

Quenselite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

Fe ore associated with calcite and barite medium grey 19.87 - 22.02 Bireflectance: slight strong, light bluish to dark brownish grey

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.14-Quenselite series IV/F.14-10 Quenselite

PbMnO2(OH)

2

Descriptions A Anhedral quenselite (medium grey, slight bireflectance) in hausmannite matrix (brownish grey, bireflectance); Långbanshyttan, Vermland, Sweden [j]; Nic. // B Quenselite (light bluish to dark brownish grey anisotropy), hausmannite (brownish grey anisotropy, red internal reflections); Långbanshyttan, Vermland, Sweden [j]; Nic. + C Radiating rounded grains of quenselite (medium grey) on hausmannite (tinted medium grey), carbonate (dark grey, bireflectance); Långbanshyttan, Vermland, Sweden [j]; Nic. //

756

Quenselite A

40 μ

C

B

158 μ

83 μ

757

Söhngeite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product in Ga-rich base-metal vein deposits dark grey colourless [5] Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.15-Söhngeite-Bernalite series IV/F.15-10 Söhngeite IV/F.15-20 Dzhalindite IV/F.15-30 Bernalite

Ga(OH)3 In(OH)3 Fe(OH)3

– 2/m 3 – 2/m 3 2/m 2/m 2/m

Description A Euhedral söhngeite in void (dark grey, slightly brighter than resin, translucent), renierite (orange brown), chalcopyrite (yellow), gallite (violet grey, lamellae in chalcopyrite), tennantite (lighter bluish grey); Kipushi, Congo [d]; Nic. //

758

Söhngeite A

28 μ

759

Dzhalindite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration mineral of indite contained in granitic rocks dark grey yellow brown [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/F.15-Söhngeite-Bernalite series IV/F.15-10 Söhngeite IV/F.15-20 Dzhalindite IV/F.15-30 Bernalite

Ga(OH)3 In(OH)3 Fe(OH)3

– 2/m 3 – 2/m 3 2/m 2/m 2/m

Descriptions A Irregular dzhalindite (dark grey) as alteration product of indite (light grey with bluish tint), quartz (slightly darker grey than dzhalindite); Dzhalindin deposit, Little Khingan Ridge, Far Eastern Region, Russia [j]; Nic. // B Dzhalindite (opaque and brown internal reflections), indite (isotropic), quartz (milky internal reflections); Dzhalindin deposit, Little Khingan Ridge, Far Eastern Region, Russia [j]; Nic. +

760

Dzhalindite A

40 μ

B

40 μ 761

Melanovanadite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

V and Ni associated with organogenic material, such as lignite brownish grey [14]

Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/G.10-Melanovanadite series IV/G.10-10 Melanovanadite

CaV4O10·5(H2O)

– 1

Descriptions A Melanovanadite (brownish grey), the dehydration cracks are filled by patronite (light grey) and other unidentified minerals (medium and dark grey); Ragra Mine (Minasragra), Junín, Cerro de Pasco, Peru [j]; Nic. // B Melanovanadite (dark brownish grey, no internal reflections observed); Ragra Mine (Minasragra), Junín, Cerro de Pasco, Peru [j]; Nic. +

762

Melanovanadite A

39 μ

B

120 μ 763

Chalcomenite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Cu-Pb selenides dark grey with turquoise tint turquoise [12] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography IV/K.06-Chalcomenite-Cesbronite series IV/K.06-10 Chalcomenite IV/K.06-20 Teineite IV/K.06-30 Cesbronite

CuSeO3·2H2O CuTeO3·2H2O Cu5(TeO3)2(OH)6·2H2O

222 222 2/m 2/m 2/m

Descriptions A Chalcomenite (strong turquoise internal reflections), silicates (brown internal reflections); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. + B Radial chalcomenite (dark grey with turquoise internal reflections) in silicate matrix (dark grey); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. // C Chalcomenite (strong turquoise internal reflections), silicates (brown internal reflections); Ato Bay, Beaverlodge Lake, Goldfields District, Saskatchewan, Canada [j]; Nic. +

764

Chalcomenite A

60 μ

C

B

83 μ

83 μ

765

Calcite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, igneous, and metamorphic rocks dark grey bright to milky [4] Bireflectance: strong, grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography V/B.02-Calcite group V/B.02-10 Vaterite V/B.02-20 Calcite V/B.02-30 Magnesite V/B.02-40 Siderite V/B.02-50 Rhodochrosite V/B.02-60 Smithsonite V/B.02-70 Sphaerocobaltite V/B.02-80 Gaspeite V/B.02-90 Otavite

CaCO3 CaCO3 MgCO3 FeCO3 MnCO3 ZnCO3 CoCO3 (Ni,Mg,Fe)CO3 CdCO3

6/m 2/m 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Anhedral calcite (white to grey internal reflections, twins), finest inclusions of hematite (red internal reflections); Predborice, Czech Republic [h]; Nic. + B Euhedral calcite (dark grey, bireflectance enhancing polysynthetic twinning), stibnite (light grey with brownish tints, bireflectance); Indarama mine, Zimbabwe [d]; Nic. // C Calcite (bright internal reflections mask anisotropy), stibnite brown to blue grey anisotropy); Indarama mine, Zimbabwe [d]; Nic. +

766

Calcite A

120 μ

C

B

125 μ

125 μ

767

Siderite (Chalybite, Iron Spar, Spathose Iron) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal veins, metasomatic, biosedimentary, metamorphic and igneous rocks dark grey light brown [5 - 8] Bireflectance: distinct



6/m 2/m 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Large grains of siderite (dark grey, strong bireflectance), pyrite (white); Vlastejovice, Czech Republic [j]; Nic. // B Large grains of siderite (bright internal reflections), pyrite (isotropic); Vlastejovice, Czech Republic [j]; Nic. +

768

Siderite A

120 μ

B

120 μ 769

Rhodochrosite (Dialogite, Manganese Spar) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, surface-near alteration of Mn-oxides dark grey white to light pink [7] Bireflectance: weak



6/m 2/m 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m – 3 2/m

Descriptions A Anhedral rhodochrosite (various dark and medium grey shades, bireflectance), alabandite (lightest grey, lower right), unidentified Mn (hydr-)oxides (very fine-grained, lighter grey) also replacing rhodochrosite; Noda Tamagawa, Iwate, Japan [c]; Nic. // B Rhodochrosite (white internal reflections), alabandite (dark, some green internal reflections), Mn (hydr-)oxides (brown internal reflections); Noda Tamagawa, Iwate, Japan [c]; Nic. +

770

Rhodochrosite A

60 μ

B

60 μ 771

Cerussite (Akrusite, White Lead Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Pb deposits medium to dark grey milky [10-12] Bireflectance: medium to dark grey

pronounced

Strunz Classification - Group Members - Chemical Formula - Crystallography V/B.04-Aragonite group V/B.04-10 Aragonite V/B.04-20 Strontianite V/B.04-30 Witherite V/B.04-40 Cerussite V/B.04-50 Alstonite V/B.04-60 Barytocalcite V/B.04-65 Olekminskite V/B.04-70 Paralstonite

CaCO3 SrCO3 BaCO3 PbCO3 BaCa(CO3)2 BaCa(CO3)2 Sr(Sr,Ca,Ba)(CO3)2 BaCa(CO3)2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m tri. 2 32 32

Descriptions A Cerussite (milky to brownish internal reflections, grey anisotropy); North field, Schauinsland Mt., Freiburg im Breisgau, Germany [a]; Nic. + B Anhedral cerussite (medium to darker grey, bireflectance) replacing galena (light grey), siliceous sandstone matrix (dark grey); Zaida, Morocco [b]; Nic. // C Cerussite (anisotropy from medium to dark grey, internal reflections), galena (dark); Zaida, Morocco [b]; Nic. +

772

Cerussite A

31 μ

C

B

125 μ

125 μ

773

Azurite (Chessylite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Cu deposits dark grey distinct blue [8] Bireflectance:

difficult to discern

greyish shades overprinted by strong blue internal reflections

Strunz Classification - Group Members - Chemical Formula - Crystallography V/C.01-Azurite-Rosasite group and related compounds V/C.01-10 Azurite Cu3(CO3)2(OH)2 V/C.01-20 Malachite Cu2(CO3)(OH)2 V/C.01-25 Georgeite Cu5(CO3)3(OH)4·6H2O V/C.01-30 Pokrovskite Mg2(CO3)(OH)2·0.5H2O V/C.01-40 Mcguinnessite (Mg,Cu)2(CO3)(OH)2 V/C.01-50 Kolwezite (Cu,Co)2(CO3)(OH)2 V/C.01-60 Glaukosphaerite (Cu,Ni)2(CO3)(OH)2 V/C.01-70 Nullaginite Ni2(CO3)(OH)2 V/C.01-80 Rosasite (Cu,Zn)2(CO3)(OH)2 V/C.01-90 Zincrosasite (Zn,Cu)2(CO3)(OH)2 V/C.01-100 Hydrozincite Zn5(CO3)2(OH)6 V/C.01-105 Brianyoungite Zn3(CO3,SO4)(OH)4 V/C.01-110 Aurichalcite (Zn,Cu)5(CO3)2(OH)6 V/C.01-120 Loseyite (Mn,Zn)7(CO3)2(OH)10 V/C.01-130 Sclarite (Zn,Mg,Mn)4Zn3(CO3)2(OH)10

A B C D

E

2/m 2/m none 2/m 2/m tri. 2/m mono. 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Azurite (bright blue) replaces calcite (colourless) along twinning planes; Santa Brigida mine, Sierra de Umango, Argentina [b]; Nic. + Void-filling azurite (medium grey) between quartz (dark grey) and schwazite (white) with outer covellite seam (blue); Mina dell’Angina, Italy [d]; Nic. // Azurite (blue internal reflections), quartz (bright internal reflections), schwazite (dark), covellite (orange anisotropy); Mina dell’Angina, Italy [d]; Nic. + Radial azurite (blue internal reflections), malachite (green internal reflections), goethite (brown internal reflections), other carbonates (transparent); Neubulach, Schwarzwald, Germany [d]; Nic. + Azurite laminae (blue internal reflections) intergrown with radial malachite (green internal reflections); Neubulach, Schwarzwald, Germany [d]; Nic. +

774

Azurite A

120 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 775

Malachite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Cu deposits dark grey with greenish tint bright green [6 - 8] Bireflectance: grey shades

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography V/C.01-Azurite-Rosasite group and related compounds V/C.01-10 Azurite Cu3(CO3)2(OH)2 V/C.01-20 Malachite Cu2(CO3)(OH)2 V/C.01-25 Georgeite Cu5(CO3)3(OH)4·6H2O V/C.01-30 Pokrovskite Mg2(CO3)(OH)2·0.5H2O V/C.01-40 Mcguinnessite (Mg,Cu)2(CO3)(OH)2 V/C.01-50 Kolwezite (Cu,Co)2(CO3)(OH)2 V/C.01-60 Glaukosphaerite (Cu,Ni)2(CO3)(OH)2 V/C.01-70 Nullaginite Ni2(CO3)(OH)2 V/C.01-80 Rosasite (Cu,Zn)2(CO3)(OH)2 V/C.01-90 Zincrosasite (Zn,Cu)2(CO3)(OH)2 V/C.01-100 Hydrozincite Zn5(CO3)2(OH)6 V/C.01-105 Brianyoungite Zn3(CO3,SO4)(OH)4 V/C.01-110 Aurichalcite (Zn,Cu)5(CO3)2(OH)6 V/C.01-120 Loseyite (Mn,Zn)7(CO3)2(OH)10 V/C.01-130 Sclarite (Zn,Mg,Mn)4Zn3(CO3)2(OH)10

2/m 2/m none 2/m 2/m tri. 2/m mono. 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Malachite (medium grey, pronounced bireflectance, some green internal reflections), heterogenite (light grey); Luiswishi, Congo [d]; Nic. // B Malachite (bright green internal reflections, strong anisotropy, cleavage), heterogenite (dark grey shades anisotropy); Luiswishi, Congo [d]; Nic. +

776

Malachite A

60 μ

B

60 μ 777

Defernite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed manganese-iron deposit dark grey red-brown [7] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography V/C.06-Brenkite-Defernite series V/C.06-10 Brenkite V/C.06-20 Holdawayite V/C.06-25 Rouvilleite V/C.06-27 Sheldrickite V/C.06-30 Defernite

Ca2(CO3)F2 Mn6(CO3)2(OH)7(Cl,OH) Na3Ca2(CO3)3F NaCa3(CO3)2F3·H2O Ca6(CO3)2-x(SiO4)x(OH)7(Cl,OH)1-2x

2/m 2/m 2/m 2/m mono. 3 2/m 2/m 2/m

Descriptions A Euhedral defernite (darker grey) in a matrix of hausmannite (medium grey); Långban, Sweden [c]; Nic. // B Defernite (red-brown internal reflections), hausmannite (pleochroitic); Långban, Sweden [c]; Nic. +

778

Defernite A

120 μ

B

120 μ 779

Jimboite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

veinlets in metamorphosed sedimentary Mn ore (rhodochrosite) dark grey with brownish tint brown [7] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography V/G.01-Kotoite-Jimboite series V/G.01-10 Kotoite V/G.01-20 Jimboite V/G.01-25 Jacquesdietrichite V/G.01-30 Takedaite

Mg3B2O6 Mn3B2O6 Cu2[BO(OH)2](OH)3 Ca3(BO3)2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 3 2/m

Descriptions A Subhedral jimboite (relatively dark grey, but lighter than the brightest position of accompanying carbonates), carbonate (dark grey shades, bireflectance); Kaso Mine, Kanuma, Tochigi Prefecture, Honshu Island, Japan [j]; Nic. // B Jimboite (brown internal reflections), carbonate (milky to brilliant internal reflections, grey anisotropy); Kaso Mine, Kanuma, Tochigi Prefecture, Honshu Island, Japan [j]; Nic. +

780

Jimboite A

40 μ

B

40 μ 781

Hulsite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed limestone at contact to granite grey with brownish tint [12] Bireflectance: strong, brown and blue grey brownish and bluish

distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography V/G.03-Warwickite-Hulsite series V/G.03-05 Pertsevite V/G.03-10 Warwickite V/G.03-15 Yuanfuliite V/G.03-20 Pinakiolite V/G.03-25 Aluminomagnesiohulsite V/G.03-30 Magnesiohulsite V/G.03-40 Hulsite

Mg2(BO3)F Mg(Ti,Fe,Al)(BO3)O (Mg,Fe)(Fe,Al,Mg,Ti,Fe)(BO3)O Mg2MnO2(BO3) Mg2(Al,Mg,Sn)(BO3)O2 (Mg,Fe)2(Mg,Fe,Sn)O2(BO3) (Fe,Mg)2(Fe,Sn)O2(BO3)

mm2 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Subhedral hulsite (brownish and bluish pleochroism, bireflectance), magnetite (lighter brownish grey), hematite (light grey) as alteration product, carbonate (dark grey); Brooks mountain, Seward peninsula, Alaska, USA [j]; Nic. // B Hulsite (strong brown and blue grey anisotropy, lamellar twinning), magnetite (isotropic), hematite (faint red internal reflections), carbonate (bright internal reflections); Brooks mountain, Seward peninsula, Alaska, USA [j]; Nic. +

782

Hulsite A

120 μ

B

120 μ 783

Ludwigite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magnesian Fe skarn, contact metamorphic deposits brownish to bluish 7.71 - 10.86 Bireflectance: distinct strong, yellowish brown to bluish violet grey brownish to bluish

Strunz Classification - Group Members - Chemical Formula - Crystallography V/G.04-Ludwigite group V/G.04-10 Ludwigite V/G.04-20 Vonsenite V/G.04-30 Azoproite V/G.04-40 Chestermanite V/G.04-50 Fredrikssonite V/G.04-60 Bonaccordite V/G.04-70 Takeuchiite V/G.04-80 Orthopinakiolite V/G.04-90 Blatterite V/G.04-100 Gaudefroyite

Mg2FeBO5 Fe2FeBO5 (Mg,Fe)2(Fe,Ti,Mg)BO5 Mg2(Fe,Mg,Al,Sb)BO3O2 Mg2(Mn,Fe)O2(BO3) Ni2FeBO5 Mg2MnO2(BO3) (Mg,Mn)2MnBO5 (Mn,Mg)35Sb3(Mn,Fe)9(BO3)16O32 Ca4Mn3-x(BO3)3(CO3)(O,OH)3

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 6

Descriptions A Undulating fibrous ludwigite (brownish to bluish pleochroism, bireflectance) partially replaced by patchy magnetite (lighter brownish grey); Ocna de Fier (Vaskö/ Eisenstein), Banat, Romania [j]; Nic. // B Ludwigite (pink, brown, and blue anisotropy), magnetite (isotropic); Ocna de Fier (Vaskö/ Eisenstein), Banat, Romania [j]; Nic. +

784

Ludwigite A

60 μ

B

60 μ 785

Vonsenite (Breislakite, Paigeite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

boron-rich skarns relatively dark brown- to blue-grey 11.68 - 14.60 Bireflectance: distinct strong, orange to brown strong, relatively dark brown- to blue-grey


A B C D E



Descriptions Massive aggregate of vonsenite (strong, but relatively dark brownish grey to blue-grey pleochroism, bireflectance); Old City Quarry, Riverside, California, USA [j]; Nic. // Vonsenite (strong orange to brown anisotropy); Old City Quarry, Riverside, California, USA [j]; Nic. + Partial replacement of vonsenite (here bluish grey) by magnetite (lighter brownish grey), calcite (dark grey); Kamaishi mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. // Euhedral vonsenite (bluish to brownish grey pleochroism, bireflectance) in calcite (dark grey); Kamaishi mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. // Vonsenite (bluish grey to brown anisotropy), calcite (transparent, multicolour internal reflections); Kamaishi mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. +

786

Vonsenite A

60 μ

C

B

125 μ

250 μ

D

E

250 μ

250 μ 787

Gaudefroyite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermally overprinted portions of Mn deposits brownish greys brown (on cracks and in thin grains) 9.46 - 12.16 Bireflectance: distinct strong, brownish grey to blue




Descriptions A Gaudefroyite (brown internal reflection are visible on cracks and in thin grains); Nchwaning, South Africa [c]; Nic. + B Euhedral gaudefroyite (medium brownish grey, bireflectance) in carbonate (dark, speckled); Nchwaning, South Africa [c]; Nic. // C Gaudefroyite (strong brownish grey to blue anisotropy), carbonate (colourless); Nchwaning, South Africa [c]; Nic. +

788

Gaudefroyite A

60 μ

C

B

500 μ

500 μ

789

Anhydrite (Calcium Sulfate) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, gangue mineral in hydrothermal ore veins dark grey clear to milky [4-7] Bireflectance: strong

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/A.08-Aphthitalite-Anhydrite series VI/A.08-10 Aphthitalite VI/A.08-20 Kalistrontite VI/A.08-30 Palmierite VI/A.08-40 Glauberite VI/A.08-50 Anhydrite

(K,Na)3Na(SO4)2 K2Sr(SO4)2 (K,Na)2Pb(SO4)2 Na2Ca(SO4)2 CaSO4

– 3 2/m – 3 2/m – 3 2/m 2/m 2/m 2/m 2/m

Descriptions A Anhedral anhydrite (dark greys, strong bireflectance, twin lamellae), grainy oldhamite (lighter grey); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. // B Anhydrite (brownish grey anisotropy), oldhamite (white internal reflections); Lichtenberg Absetzer Mine, Ronneburg, Gera, Germany [h]; Nic. +

790

Anhydrite A

60 μ

B

60 μ 791

Barite (Baroselenite, Heavy Spar, Wolnyn) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sedimentary, late gangue mineral in hydrothermal ores dark grey clear to milky [8] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/A.09-Barite group VI/A.09-10 Celestine VI/A.09-20 Barite VI/A.09-30 Hashemite VI/A.09-40 Kerstenite VI/A.09-50 Anglesite

SrSO4 BaSO4 Ba(Cr,S)O4 PbSeO4 PbSO4


Descriptions A Barite crystals (dark grey), sphalerite (medium grey), pyrite (cream); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // B Barite (white and multicolour internal reflections), sphalerite (brown internal reflections), pyrite (isotropic); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

792

Barite A

120 μ

B

120 μ 793

Anglesite (Lead Spar, Lead Vitriol) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation product of Pb ores dark grey clear to milky [12-16] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/A.09-Barite group VI/A.09-10 Celestine VI/A.09-20 Barite VI/A.09-30 Hashemite VI/A.09-40 Kerstenite VI/A.09-50 Anglesite

A

B

C D E

SrSO4 BaSO4 Ba(Cr,S)O4 PbSeO4 PbSO4


Descriptions Anglesite (same as pictures B & C; white to slightly brownish internal reflections), cerussite and calcite (bright internal reflections, but less brilliant), galena isotropic); unknown locality [a]; Nic. + Irregular anglesite (lightest grey) in contact with cerussite (at upper border of largest anglesite grain, slightly darker, bireflectance) and calcite (darker than cerussite, bireflectance), galena (almost white, small inclusions in cerussite); unknown locality [a]; Nic. // Anglesite, cerussite, calcite (all like previous photo; note different bireflectance shades), galena (almost white); unknown locality [a]; Nic. // Euhedral anglesite (medium grey), pyrite (cream), sphalerite (lighter grey than anglesite), galena (grey); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // Anglesite (white and multicolour internal reflections), pyrite (isotropic), sphalerite (isotropic), galena (isotropic); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

794

Anglesite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 795

Jarosite

(Antunezite, Borgströmite, Cyprusite, Kolosorukite, Moronolite, Pastreite, Raimondite, Utahite)


oxidation zone of Fe sulfides in arid climates, alteration product of submarine hydrothermal sulfides bluish grey orange to red-brown [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/B.11-Alunite group, Natroalunite-Jarosite-Beaverite VI/B.11-10 Natroalunite NaAl3(SO4)2(OH)6 VI/B.11-20 Alunite KAl3(SO4)2(OH)6 VI/B.11-30 Ammonioalunite (NH4)Al3(SO4)2(OH)6 VI/B.11-40 Minamiite (Na,Ca,K)Al3(SO4)2(OH)6 VI/B.11-43 Huangite Ca0.5Al3(SO4)2(OH)6 VI/B.11-45 Walthierite Ba0.5Al3(SO4)2(OH)6 VI/B.11-50 Natrojarosite NaFe3(SO4)2(OH)6 VI/B.11-60 Jarosite KFe3(SO4)2(OH)6 VI/B.11-65 Dorallcharite (Tl,K)Fe3(SO4)2(OH)6 VI/B.11-70 Ammoniojarosite (NH4)Fe3(SO4)2(OH)6 VI/B.11-80 Hydroniumjarosite (H3O)Fe3(SO4)2(OH)6 VI/B.11-90 Argentojarosite AgFe3(SO4)2(OH)6 VI/B.11-100 Plumbojarosite PbFe6(SO4)4(OH)12 VI/B.11-110 Osarizawaite PbCuAl2(SO4)2(OH)6 VI/B.11-120 Beaverite PbCu(Fe,Al)2(SO4)2(OH)6

– 3 2/m trig. – 3 2/m – 3 2/m – 3 2/m – 3 2/m 3m 3 – 3 2/m 3m 3m 3m – 3 2/m 3m 3m

Descriptions A Jarosite (bluish grey) on barite (dark grey), pyrite (cream); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. // B Jarosite (orange internal reflections), barite (greyish internal reflections), pyrite (isotropic); JADE hydrothermal field, Okinawa Trough, Japan [c]; Nic. +

796

Jarosite A

60 μ

B

60 μ 797

Gypsum (Satin Spar, Selenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

evaporites, soils in arid climates, rarely hydrothermal, oxidation zone of sulfide deposits dark grey clear to white [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/C.22-Bassanite-Ardealite series VI/C.22-10 Bassanite VI/C.22-20 Gypsum VI/C.22-25 Rapidcreekite VI/C.22-30 Ardealite

2CaSO4·H2O CaSO4·2H2O Ca2(SO4)(CO3)·4H2O Ca2(SO4)(HPO4)·4H2O

ortho. 2/m 2/m 2/m 2/m m

Descriptions A Euhedral gypsum (dark grey, cleavage parallel to long axis), sphalerite (medium grey), pyrite (cream); Meggen Mine, Lennestadt, Germany [a]; Nic. // B Gypsum (milky internal reflections, pronounced cleavage), sphalerite (isotropic, few red brown internal reflections), pyrite (isotropic, slightly lighter than sphalerite); Meggen Mine, Lennestadt, Germany [a]; Nic. +

798

Gypsum A

120 μ

B

120 μ 799

Crocoite (Lehmannite, Red Lead Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised hydrothermal Pb veins infiltrated by Cr bearing fluids medium grey bright orange-red [32] Bireflectance: weak greenish to violet greenish to violet grey

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/F.01-Tarapacaite-Crocoite series VI/F.01-10 Tarapacaite VI/F.01-20 Chromatite VI/F.01-30 Crocoite

A B C D

E

K2CrO4 CaCrO4 PbCrO4

2/m 2/m 2/m 4/m 2/m 2/m 2/m

Descriptions Irregular vug filling of crocoite (medium grey) in quartz (dark grey); Callenberg, Saxony, Germany [c]; Nic. // Anhedral crocoite (slight orange internal reflections, greenish to violet grey pleochroism, bireflectance), quartz (dark grey); Callenberg, Saxony, Germany [c]; Nic. // Crocoite (bright orange red internal reflections, greenish to violet anisotropy), quartz (colourless internal reflections); Callenberg, Saxony, Germany [c]; Nic. + Subhedral crocoite (slight orange internal reflections, distinct greenish to violet grey pleochroism, bireflectance), vauquelinite (brownish grey, at top), quartz (dark grey); Callenberg, Saxony, Germany [c]; Nic. // Crocoite (bright orange red internal reflections), vauquelinite (yellow internal reflections), quartz (colourless internal reflections); Callenberg, Saxony, Germany [c]; Nic. +

800

Crocoite A

60 μ

C

B

125 μ

125 μ

D

E

125 μ

125 μ 801

Vauquelinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised hydrothermal Pb veins infiltrated by Cr bearing fluids medium brownish greys green, yellow, orange, brown [15] Bireflectance: slight

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/F.02-Wattersite-Satanaite series VI/F.02-03 Wattersite VI/F.02-05 Edoylerite VI/F.02-07 Deanesmithite VI/F.02-10 Vauquelinite VI/F.02-20 Fornacite VI/F.02-30 Molybdofornacite VI/F.02-40 Phoenicochroite VI/F.02-50 Santanaite

Hg5CrO6 Hg3CrO4S2 Hg5CrO5S2 Pb2Cu(CrO4)(PO4)(OH) Pb2Cu(CrO4)(AsO4)(OH) Pb2Cu[(As,P)O4][(Mo,Cr)O4](OH) Pb2(CrO4)O Pb9Pb+2CrO16

2/m 2/m – 1 2/m 2/m 2/m 2/m 622

Descriptions A Anhedral vauquelinite (brownish grey), crocoite (greenish grey, lighter than vauquelinite, slight tint from orange internal reflections), quartz (dark grey); Callenberg, Saxony, Germany [c]; Nic. // B Vauquelinite (green to brown internal reflections), crocoite (strong orange internal reflections), quartz (colourless); Callenberg, Saxony, Germany [c]; Nic. +

802

Vauquelinite A

60 μ

B

60 μ 803

Scheelite (Calcium Tungstate, Trimontite, Tungstein) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatitic-pneumatolytic dark to medium grey bright, colourless, yellow, pinkish, brown 9.68 - 10.05 Bireflectance: faint

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/G.01-Scheelite-Wulfenite series, (Powellite-Raspite) VI/G.01-10 Powellite CaMoO4 VI/G.01-20 Scheelite CaWO4 VI/G.01-25 Paraniite-(Y) Ca2Y(AsO4)(WO4)2 VI/G.01-30 Wulfenite PbMoO4 VI/G.01-40 Stolzite PbWO4 VI/G.01-50 Raspite PbWO4 VI/G.01-60 Koechlinite Bi2MoO6 VI/G.01-70 Russellite Bi2WO6

4/m 4/m 4/m 4/m 4/m 2/m 2/m 2/m 2/m mm2

Descriptions A Euhedral scheelite twins (medium grey, faint bireflectance) in silicates (darker grey); Mittersill, Austria [b]; Nic. // B Scheelite (bright pinkish to colourless internal reflections); Mittersill, Austria [b]; Nic. +

804

Scheelite A

60 μ

B

60 μ 805

Wulfenite (Yellow Lead Ore) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

alteration mineral in Pb deposits medium grey bright yellow, orange [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VI/G.01-Scheelite-Wulfenite series, (Powellite-Raspite) VI/G.01-10 Powellite CaMoO4 VI/G.01-20 Scheelite CaWO4 VI/G.01-25 Paraniite-(Y) Ca2Y(AsO4)(WO4)2 VI/G.01-30 Wulfenite PbMoO4 VI/G.01-40 Stolzite PbWO4 VI/G.01-50 Raspite PbWO4 VI/G.01-60 Koechlinite Bi2MoO6 VI/G.01-70 Russellite Bi2WO6

4/m 4/m 4/m 4/m 4/m 2/m 2/m 2/m 2/m mm2

Descriptions A Subhedral wulfenite (medium grey, numerous breakouts) next to cerussite (slightly darker grey, containing white specs of galena) and other carbonates (dark grey); Miess, Slovenia [c]; Nic. // B Wulfenite (bright yellow internal reflections), cerussite (dark grey shades); gang carbonates (white to brownish internal reflections); Miess, Slovenia [c]; Nic. +

806

Wulfenite A

120 μ

B

120 μ 807

Monazite (Edwarsite, Eremite, Monazitoide, Phosphocerite, Urdite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

felsic rocks, pegmatites, contact metamorphic rocks, high-temperature hydrothermal veins cream-grey light yellow, brown, brilliant [20] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/A.15-Monazite group VII/A.15-10 Monazite-(La) VII/A.15-20 Monazite-(Ce) VII/A.15-30 Monazite-(Nd) VII/A.15-35 Monazite-(Sm) VII/A.15-40 Cheralite-(Ce) VII/A.15-50 Brabantite

(La,Ce,Nd)PO4 (Ce,La,Nd,Th)PO4 (Nd,Ce,La)(P,Si)O4 SmPO4 (Ce,Ca,Th)(P,Si)O4 CaTh(PO4)2

2/m 2/m 2/m 2/m 2/m 2

Descriptions A Euhedral monazite (medium grey), goethite (lighter grey) as alteration product on cracks; Central African Republic [c]; Nic. // B Monazite (clear to brilliant internal reflections), goethite (yellow to brown internal reflections); Central African Republic [c]; Nic. +

808

Monazite A

120 μ

B

120 μ 809

Libethenite (Chinoite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Cu deposits medium grey with greenish tint bright olive-green [12] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/B.06-Adamite group, Libethenite-Paradamite VII/B.06-10 Libethenite Cu2(PO4)(OH) VII/B.06-20 Olivenite Cu2AsO4(OH) VII/B.06-30 Adamite Zn2(AsO4)(OH) VII/B.06-40 Eveite Mn2(AsO4)(OH) VII/B.06-50 Tarbuttite Zn2(PO4)(OH) VII/B.06-60 Paradamite Zn2(AsO4)(OH)

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 1 – 1

Descriptions A Libethenite (medium grey) and malachite (dark grey, bireflectance) replace sulvanite (light yellow); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. // B Libethenite (bright olive green internal reflections), malachite (more turquoise-green internal reflections), sulvanite (isotropic); Burra Burra Mine, Mt. Lofty Ranges, South Australia, Australia [j]; Nic. +

810

Libethenite A

60 μ

B

60 μ 811

Duftite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of hydrothermal base metal deposits medium grey bright yellow green [15] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/B.26-Adelite-Duftite group VII/B.26-10 Adelite VII/B.26-15 Gottlobite VII/B.26-20 Nickelaustinite VII/B.26-30 Cobaltaustinite VII/B.26-40 Austinite VII/B.26-50 Conichalcite VII/B.26-60 Tangeite VII/B.26-70 Gabrielsonite VII/B.26-80 Duftite-alpha VII/B.26-80 Duftite-beta

CaMg(AsO4)(OH) CaMg(VO4,AsO4)(OH) Ca(Ni,Zn)(AsO4)(OH) CaCo(AsO4)(OH) CaZn(AsO4)(OH) CaCu(AsO4)(OH) CaCu(VO4)(OH) PbFe(AsO4)(OH) PbCu(AsO4)(OH) PbCu(AsO4)(OH)

222 222 222 222 222 222 222 mm2 222 222

Descriptions A Coarse duftite needles (medium grey) intergrown with radial malachite (darker grey); Tsumeb, Otjikoto Region, Namibia [j]; Nic. // B Duftite (bright yellow green internal reflections), malachite (green internal reflections); Tsumeb, Otjikoto Region, Namibia [j]; Nic. +

812

Duftite A

40 μ

B

40 μ 813

Descloizite (Ramirit, Tritochlorite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Pb-Cu-Zn deposits medium greys with brownish tint yellow to brown [17] Bireflectance: slight brownish grey shades

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/B.27-Descloizite group VII/B.27-10 Arsendescloizite VII/B.27-20 Descloizite VII/B.27-30 Mottramite VII/B.27-40 Cechite VII/B.27-50 Pyrobelonite

PbZn(AsO4)(OH) PbZn(VO4)(OH) PbCu(VO4)(OH) Pb(Fe,Mn)(VO4)(OH) PbMn(VO4)(OH)

222 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Mass of descloizite crystals (medium greys with brownish tint, bireflectance), colloform goethite on the left (similar reflectivity, but slightly bluish), small specs of hematite (lightest grey); Berg Aukas, Namibia [c]; Nic. // B Descloizite (strong anisotropy enhanced by position of polariser, bright to darker brown internal reflections), goethite (darker brown, radial), hematite (red internal reflections); Berg Aukas, Namibia [c]; Nic. + (+2°)

814

Descloizite A

60 μ

B

60 μ 815

Pyromorphite (Phosphomimetite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of base-metal deposits dark greenish grey bright green to brown [4] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/B.39-Apatite-Pyromorphite group VII/B.39-00 Apatite VII/B.39-10 Fluorapatite VII/B.39-20 Chlorapatite VII/B.39-30 Hydroxylapatite VII/B.39-40 Carbonatehydroxylapatite VII/B.39-50 Carbonatefluorapatite VII/B.39-60 Svabite VII/B.39-70 Turneaureite VII/B.39-80 Johnbaumite VII/B.39-90 Fermorite VII/B.39-95 Fluorcaphite VII/B.39-100 Strontiumapatite VII/B.39-110 Belovite-(Ce) VII/B.39-115 Belovite-(La) VII/B.39-117 Kuannersuite-(Ce) VII/B.39-120 Alforsite VII/B.39-130 Morelandite VII/B.39-140 Hedyphane VII/B.39-150 Pyromorphite VII/B.39-160 Mimetite VII/B.39-165 Clinomimetite VII/B.39-170 Vanadinite

Ca5(PO4)3(OH,F,Cl) Ca5(PO4)3F Ca5(PO4)3Cl Ca5(PO4)3(OH) Ca5(PO4,CO3)3(OH) Ca5(PO4,CO3)3F Ca5(AsO4)3F Ca5[(As,P)O4]3Cl Ca5(AsO4)3(OH) (Ca,Sr)5(AsO4,PO4)3(OH) (Ca,Sr,Ce,Na)5(PO4)3F (Sr,Ca)5(PO4)3(F,OH) (Sr,Ce,Na,Ca)5(PO4)3(OH) (Sr,La,Ce,Ca)5(PO4)3(F,OH) Ba6Na2REE2(PO4)6FCl Ba5(PO4)3Cl (Ba,Ca,Pb)5(AsO4,PO4)3Cl Ca2Pb3(AsO4)3Cl Pb5(PO4)3Cl Pb5(AsO4)3Cl Pb5(AsO4)3Cl Pb5(VO4)3Cl

6/m 6/m 6/m 6/m 6/m 6/m 6/m 6/m hex. 6/m 6 6/m 3 – 3 – 3 6/m hex. 6/m 6/m 6/m 2/m 6/m

Descriptions A Euhedral pyromorphite (dark greenish grey), quartz crystals (darker grey), fine-grained carbonate (slightly lighter grey than quartz, faint internal reflections); Neubulach, Black Forest, Germany [d]; Nic. // B Pyromorphite (bright green internal reflections), quartz (almost clear), carbonate (whitish internal reflections); Neubulach, Black Forest, Germany [d]; Nic. +

816

Pyromorphite A

60 μ

B

60 μ 817

Mimetite (Gorlandite, Petterdite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Pb deposits medium grey bright greenish yellow [15] Bireflectance:



6/m 6/m 6/m 6/m 6/m 6/m 6/m 6/m hex. 6/m 6 6/m 3 3 3 6/m hex. 6/m 6/m 6/m 2/m 6/m

Descriptions A Crust of radiating mimetite crystals (medium grey), small patches of goethite (slightly darker and more brownish, lower left); San Pedro Corralitos, Mexico [c]; Nic. // B Mimetite crystals (clear to light yellow internal reflections), goethite (reddish brown); San Pedro Corralitos, Mexico [c]; Nic. +

818

Mimetite A

120 μ

B

120 μ 819

Vanadinite (Endlichite = As) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Pb deposits medium grey orange-red to brown [20] Bireflectance: greyish anisotropy masked by strong internal reflections



6/m 6/m 6/m 6/m 6/m 6/m 6/m 6/m hex. 6/m 6 6/m 3 – 3 – 3 6/m hex. 6/m 6/m 6/m 2/m 6/m

Descriptions A Aggregate of vanadinite crystals (medium grey, small orange internal reflection) replacing unknown mineral (center); Taouz, Tadaout, Morocco [c]; Nic. // B Vanadinite (anisotropy mainly masked by light to darker brown internal reflections); Taouz, Tadaout, Morocco [c]; Nic. + C Vanadinite (bright yellow to orange internal reflections); Taouz, Tadaout, Morocco [c]; Nic. +

820

Vanadinite A

120 μ

C

B

250 μ

250 μ

821

Sahlinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Mn-Fe deposit associated with extremely complex skarns and pegmatites medium brownish grey yellow [17] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/B.40-Atelestite-Kombatite series VII/B.40-20 Georgiadesite VII/B.40-30 Sahlinite VII/B.40-40 Kombatite

Pb4(AsO3)Cl4(OH) Pb14(AsO4)2O9Cl4 Pb14(VO4)2O9Cl4

2/m 2/m 2/m

Descriptions A Sahlinite with speckled appearance (medium brownish grey, yellow internal reflections) intergrown with hausmannite (slightly lighter grey than sahlinite); Långban, Sweden [c]; Nic. // B Sahlinite(bright yellow internal reflections), hausmannite (reddish-brown internal reflections); Långban, Sweden [c]; Nic. +

822

Sahlinite A

60 μ

B

60 μ 823

Erythrine (Rhodoite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Co-bearing deposits dark grey bright red to pink [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/C.13-Vivianite group VII/C.13-10 Bobierrite VII/C.13-20 Manganesehörnesite VII/C.13-20 Cattiite VII/C.13-30 Baricite VII/C.13-40 Vivianite VII/C.13-45 Arupite VII/C.13-50 Hörnesite VII/C.13-60 Parasymplesite VII/C.13-70 Erythrine VII/C.13-80 Annabergite VII/C.13-90 Köttigite

Mg3(PO4)2·8H2O (Mn,Mg)3(AsO4)2·8H2O Mg3(PO4)2·22H2O (Mg,Fe)3(PO4)2·8H2O Fe3(PO4)2·8H2O (Ni,Fe)3(PO4)2·8H2O Mg3(AsO4)2·8H2O Fe3(AsO4)2·8H2O Co3(AsO4)2·8H2O Ni3(AsO4)2·8H2O Zn3(AsO4)2·8H2O

2/m 2/m – 1 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Radial erythrine (pink internal reflections), goethite (brown internal reflections); Bou Azzer, Morocco[c]; Nic. + B Stacked erythrine crystals (darker grey) with quartz matrix (brownish grey); Bou Azzer, Morocco[c]; Nic. // C Erythrine (red internal reflections), quartz (white to colourless internal reflections); Bou Azzer, Morocco[c]; Nic. +

824

Erythrine A

60 μ

C

B

250 μ

250 μ

825

Annabergite (Nickel Bloom) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidation zone of Ni ores dark grey bright green [9] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VII/C.13-Vivianite group VII/C.13-10 Bobierrite VII/C.13-20 Manganesehörnesite VII/C.13-20 Cattiite VII/C.13-30 Baricite VII/C.13-40 Vivianite VII/C.13-45 Arupite VII/C.13-50 Hörnesite VII/C.13-60 Parasymplesite VII/C.13-70 Erythrine VII/C.13-80 Annabergite VII/C.13-90 Köttigite

Mg3(PO4)2·8H2O (Mn,Mg)3(AsO4)2·8H2O Mg3(PO4)2·22H2O (Mg,Fe)3(PO4)2·8H2O Fe3(PO4)2·8H2O (Ni,Fe)3(PO4)2·8H2O Mg3(AsO4)2·8H2O Fe3(AsO4)2·8H2O Co3(AsO4)2·8H2O Ni3(AsO4)2·8H2O Zn3(AsO4)2·8H2O

2/m 2/m 1 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Anhedral annabergite (dark grey with greenish tint), tennantite (medium greenish grey), carbonates (dark grey); Providencia Mine, Villamanin, Cármenes District, Spain [a]; Nic. // B Annabergite (bright green internal reflections, brownish to dark in central mixture with Fe-hydroxides), tennantite (isotropic), carbonates (white to yellowish internal reflections); Providencia Mine, Villamanin, Cármenes District, Spain [a]; Nic. +

826

Annabergite A

45 μ

B

45 μ 827

Willemite (Troostite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed Zn ores dark brownish grey white, grey, orange [10] Bireflectance:

slight

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/A.01-Phenakite series VIII/A.01-10 Phenakite VIII/A.01-20 Willemite VIII/A.01-30 Eucryptite

Be2SiO4 Zn2SiO4 LiAlSiO4

– 3 – 3 – 3

Descriptions A Euhedral willemite (slightly brownish grey, bireflectance), goethite (slightly darker grey); Stupfelsberg Limestone quarry, Nußloch, Heidelberg, Baden-Württemberg, Germany [j]; Nic. / / B Willemite (bright internal reflections, striation along long axis), goethite (brown internal reflections); Stupfelsberg Limestone quarry, Nußloch, Heidelberg, Baden-Württemberg, Germany [j]; Nic. +

828

Willemite A

120 μ

B

120 μ 829

Olivine (Chrysolite, Peridote, Forsterite/Fayalite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

mafic/ultramafic and metamorphic rocks dark grey depending on type: yellowish to green and brown [7] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/A.04-Olivine group VIII/A.04-00 Olivine VIII/A.04-10 Forsterite VIII/A.04-20 Fayalite VIII/A.04-30 Tephroite VIII/A.04-40 Liebenbergite VIII/A.04-50 Laihunite

A B C D E

(Mg,Fe)2SiO4 Mg2SiO4 Fe2SiO4 Mn2SiO4 (Ni,Mg)2SiO4 Fe3(SiO4)2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Olivine (dark grey), partially altered to serpentine (dark grey network), chromite (lightest grey); Vardos, Greece [b]; Nic. // Olivine (yellow to white internal reflections), serpentine (yellow internal reflections), chromite (isotropic); Vardos, Greece [b]; Nic. + Olivine (green internal reflections), ilmenite (here dark); Michelsberg Quarry, Katzenbuckel Mt., Eberbach, Odenwald, Baden-Württemberg, Germany [j]; Nic. + Olivine fully replaced and also outlined by ilmenite (grey, bireflectance); Michelsberg Quarry, Katzenbuckel Mt., Eberbach, Odenwald, Baden-Württemberg, Germany [j]; Nic. // Ilmenite (medium and dark grey anisotropy) replacing and outlining olivine; Michelsberg Quarry, Katzenbuckel Mt., Eberbach, Odenwald, Baden-Württemberg, Germany [j]; Nic. +

830

Olivine A

239 μ

C

B

500 μ

188 μ

D

E

250 μ

250 μ 831

Almandine Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphic dark grey with creamish hue depending on type: bright orange, pink, red, brown, green [7] Bireflectance: isotropic

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/A.08-Garnet group, Pyrope-Henritermierite VIII/A.08-10 Pyrope Mg3Al2(SiO4)3 VIII/A.08-20 Almandine Fe3Al2(SiO4)3 VIII/A.08-30 Spessartine Mn3Al2(SiO4)3 VIII/A.08-40 Calderite (Mn,Ca)3(Fe,Al)2(SiO4)3 VIII/A.08-50 Knorringite Mg3Cr2(SiO4)3 VIII/A.08-60 Majorite Mg3(Fe,Al,Si)2(SiO4)3 VIII/A.08-70 Grossular Ca3Al2(SiO4)3 VIII/A.08-80 Hibschite Ca3Al2(SiO4)3-x(OH)4x VIII/A.08-90 Katoite Ca3Al2(SiO4)3-x(OH)4x VIII/A.08-100 Hydrougrandite (Ca,Mg,Fe)3(Fe,Al)2(SiO4)3-x(OH)4x VIII/A.08-110 Andradite Ca3Fe2(SiO4)3 VIII/A.08-120 Schorlomite Ca3(Ti,Fe,Al)2[(Si,Fe,Fe)O4]3 VIII/A.08-125 Morimotoite Ca3TiFeSi3O12 VIII/A.08-130 Uvarovite Ca3Cr2(SiO4)3 VIII/A.08-138 Yamatoite (Mn,Ca)3(V,Al)2(SiO4)3 VIII/A.08-140 Goldmanite Ca3(V,Al,Fe)2(SiO4)3 VIII/A.08-150 Kimzeyite Ca3(Zr,Ti)2(Si,Al,Fe)3O12 VIII/A.08-160 Henritermierite Ca3(Mn,Al)2(SiO4)2(OH)4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m

Descriptions A Euhedral almandine (medium grey with lemon tint) in pyrite (cream) and silicate matrix (darker grey), rutile (bluish grey); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // B Almandine (pink internal reflections), silicates (milky internal reflections); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. +

832

Almandine A

60 μ

B

60 μ 833

Henritermierite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

late stage mineral in carbonatite vein dark brownish grey apricot-orange 11,49 - 12,75 Bireflectance: weak, brownish

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/A.08-Garnet group, Pyrope-Henritermierite VIII/A.08-10 Pyrope Mg3Al2(SiO4)3 VIII/A.08-20 Almandine Fe3Al2(SiO4)3 VIII/A.08-30 Spessartine Mn3Al2(SiO4)3 VIII/A.08-40 Calderite (Mn,Ca)3(Fe,Al)2(SiO4)3 VIII/A.08-50 Knorringite Mg3Cr2(SiO4)3 VIII/A.08-60 Majorite Mg3(Fe,Al,Si)2(SiO4)3 VIII/A.08-70 Grossular Ca3Al2(SiO4)3 VIII/A.08-80 Hibschite Ca3Al2(SiO4)3-x(OH)4x VIII/A.08-90 Katoite Ca3Al2(SiO4)3-x(OH)4x VIII/A.08-100 Hydrougrandite (Ca,Mg,Fe)3(Fe,Al)2(SiO4)3-x(OH)4x VIII/A.08-110 Andradite Ca3Fe2(SiO4)3 VIII/A.08-120 Schorlomite Ca3(Ti,Fe,Al)2[(Si,Fe,Fe)O4]3 VIII/A.08-125 Morimotoite Ca3TiFeSi3O12 VIII/A.08-130 Uvarovite Ca3Cr2(SiO4)3 VIII/A.08-138 Yamatoite (Mn,Ca)3(V,Al)2(SiO4)3 VIII/A.08-140 Goldmanite Ca3(V,Al,Fe)2(SiO4)3 VIII/A.08-150 Kimzeyite Ca3(Zr,Ti)2(Si,Al,Fe)3O12 VIII/A.08-160 Henritermierite Ca3(Mn,Al)2(SiO4)2(OH)4

– 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m – 4/m 3 2/m 4/m 2/m 2/m

Descriptions A Anhedral to subhedral henritermierite aggregates (dark grey but lighter than normal gangue minerals), marokite (slight pinkish grey anisotropy), small braunite crystals (light grey), other silicates (dark grey); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. // B Henritermierite (dark apricot colour internal reflections), marokite (brownish anisotropy), braunite (brown to blue anisotropy), silicates (bright milky internal reflections); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. +

834

Henritermierite A

60 μ

B

60 μ 835

Coffinite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

sediment impregnations, replacements of uraninite dark grey often none, occasionally greenish to yellow to orange [4] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/A.09-Zircon-Thorogummite series VIII/A.09-05 Reidite VIII/A.09-10 Zircon VIII/A.09-20 Hafnon VIII/A.09-30 Thorite VIII/A.09-40 Coffinite VIII/A.09-50 Thorogummite

A

B C D E

ZrSiO4 ZrSiO4 HfSiO4 ThSiO4 U(SiO4)1-x(OH)4x Th(SiO4)1-x(OH)4x

4/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m

Descriptions Coffinite (dark grey) replacing botryoidal uraninite (lighter grey) along cracks, galena (light grey, mainly on cracks, specs of safflorite (lightest grey); Himmelsfürst Mine, Freiberg, Germany [g]; Nic. // Coffinite (dark grey, desiccation cracks) replacing uraninite (lighter grey patches next to coffinite), hematite (medium grey) on cracks; Menzenschwand, Black Forest, Germany [g]; Nic. // Coffinite (from greenish yellow internal reflections to almost opaque), uraninite (isotropic), hematite (bright red internal reflections); Menzenschwand, Black Forest, Germany [g]; Nic. + Coffinite (yellow internal reflections), pyrite (isotropic specs), hematite (bright red internal reflections); Menzenschwand, Black Forest, Germany [g]; Nic. + Coffinite (dark green internal reflections) and hematite (red internal reflections) replacing uraninite, calcite (white internal reflections); Himmelsfürst Mine, Freiberg, Germany [g]; Nic. +

836

Coffinite A

60 μ

C

B

125 μ

125 μ

D

E

50 μ

125 μ 837

Topaz (Pycnite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

pegmatites, high-temperature quartz veins, granites and rhyolites dark grey light to yellowish [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/B.02-Disthene series VIII/B.02-10 Sillimanite VIII/B.02-20 Andalusite VIII/B.02-30 Kanonaite VIII/B.02-40 Kyanite VIII/B.02-50 Mullite VIII/B.02-60 Yoderite VIII/B.02-70 Topaz

Al2SiO5 Al2SiO5 (Mn,Al)AlSiO5 Al2SiO5 Al(4+2x)Si(2-2x)O(10-x) Mg2(Al,Fe)6Si4O18(OH)2 Al2SiO4(F,OH)2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m – 1 2/m 2/m 2/m 2 2/m 2/m 2/m

Descriptions A Anhedral topaz (darkest grey) in quartz (dark grey); Horni Slavkov, Czech Republic [b]; Nic. // B Anhedral topaz (yellow internal reflections), quartz (colourless); Horni Slavkov, Czech Republic [b]; Nic. +

838

Topaz A

239 μ

B

239 μ 839

Braunite (Heteroclase) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphic, supergene Mn oxide deposits medium grey few, brown 18.40 - 19.30 Bireflectance: slight olive to brownish greys

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/B.09-Braunite-Långbanite-Katoptrite series VIII/B.09-03 Braunite-I Mn7SiO12 VIII/B.09-05 Abswurmbachite CuMn6SiO12 VIII/B.09-07 Neltnerite CaMn6SiO12 VIII/B.09-10 Franciscanite-III Mn6V2Si2(O,OH)14 VIII/B.09-10 Franciscanite-VIII Mn3(V,[ ])1-x(SiO4)(O,OH)3 VIII/B.09-12 Orebroite-III Mn6(Fe,Sb)2Si2(O,OH)14 VIII/B.09-12 Orebroite-VIII Mn3(Sb,Fe)SiO4(O,OH)3 VIII/B.09-14 Welinite-III Mn6(W,Mg)2Si2(O,OH)14 VIII/B.09-14 Welinite-VIII (Mn,Mg)3(W,Mn)1-x(SiO4)(O,OH)3 VIII/B.09-17 Långbanite (Mn,Ca,Fe)4(Mn,Fe)9SbSi2O24 VIII/B.09-20 Yeatmanite Mn9Zn6Sb2Si4O28 VIII/B.09-30 Katoptrite (Mn,Mg)13(Al,Fe)4Sb2Si2O28

A

B C D E

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 3 3 3 3 3 3 2/m – 1 2/m

Descriptions Braunite crystals (brownish grey, slight bireflectance), partially cemented by crednerite (light grey, lamellar, strong bireflectance between white and grey), silicates (dark grey); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. // Aggregate of subhedral braunite grains (medium grey), hausmannite inclusions (similar grey shade to slightly darker, twin lamellae); Långbanshyttan, Vermland, Sweden [j]; Nic. // Braunite (brownish grey anisotropy), hausmannite (brownish grey anisotropy, specs of redbrown internal reflections); Långbanshyttan, Vermland, Sweden [j]; Nic. + Anhedral braunite (medium grey) intergrown with winchite (dark grey); Tirodi, India [c]; Nic. / / Braunite (greenish to brownish greys anisotropy), winchite (violet internal reflections); Tirodi, India [c]; Nic. +

840

Braunite A

40 μ

C

B

125 μ

125 μ

D

E

250 μ

250 μ 841

Neltnerite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal Mn oxide deposits dark grey [14] Bireflectance: pronounced, grey to almost black

strong

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/B.09-Braunite-Långbanite-Katoptrite series VIII/B.09-03 Braunite-I Mn7SiO12 VIII/B.09-05 Abswurmbachite CuMn6SiO12 VIII/B.09-07 Neltnerite CaMn6SiO12 VIII/B.09-10 Franciscanite-III Mn6V2Si2(O,OH)14 VIII/B.09-10 Franciscanite-VIII Mn3(V,[ ])1-x(SiO4)(O,OH)3 VIII/B.09-12 Orebroite-III Mn6(Fe,Sb)2Si2(O,OH)14 VIII/B.09-12 Orebroite-VIII Mn3(Sb,Fe)SiO4(O,OH)3 VIII/B.09-14 Welinite-III Mn6(W,Mg)2Si2(O,OH)14 VIII/B.09-14 Welinite-VIII (Mn,Mg)3(W,Mn)1-x(SiO4)(O,OH)3 VIII/B.09-17 Långbanite (Mn,Ca,Fe)4(Mn,Fe)9SbSi2O24 VIII/B.09-20 Yeatmanite Mn9Zn6Sb2Si4O28 VIII/B.09-30 Katoptrite (Mn,Mg)13(Al,Fe)4Sb2Si2O28

4/m 2/m 2/m 4/m 2/m 2/m 4/m 2/m 2/m 3 3 3 3 3 3 2/m – 1 2/m

Descriptions A Euhedral neltnerite (strong dark grey bireflectance similar to gangue minerals and brighter) intergrown with marokite (slight pinkish grey); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. / / B Neltnerite (strong grey to almost black anisotropy, faint brown internal reflections), marokite (dark to olive anisotropy, faint brown internal reflections), silicates (milky internal reflections and interference colours); Tachgagalt Mine, Ouarzazate, Morocco [j]; Nic. +

842

Neltnerite A

16 μ

B

16 μ 843

Titanite (Grothite = Al, Keilhauite = REE, Sphene, Yttro-titanite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

intermediate to felsic plutonic rocks, pegmatites, alpine veins, gneisses, schists, skarns dark to medium grey red-brown, sometimes green and yellow 9.43 - 11.0 Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/B.12-Titanite series VIII/B.12-10 Titanite VIII/B.12-15 Vanadomalayaite VIII/B.12-20 Malayaite VIII/B.12-30 Trimounsite-(Y)

A B C D

CaTiSiO5 CaVOSiO4 CaSnSiO5 = CaSnOSiO4 (Y,REE)2Ti2SiO9

2/m 2/m 2/m 2/m

Descriptions Large anhedral titanite (medium grey; brown internal reflections occasionally shine through) in siliceous matrix (dark grey); Rasvumchor mine, Kola Peninsula, Russia [c]; Nic. // Titanite (strong brown internal reflections), siliceous matrix (light grey); Rasvumchor mine, Kola Peninsula, Russia [c]; Nic. + Large euhedral keilhauite crystal (darker grey; compare reflection colour with picture A) with oriented exsolution of rutile (lighter grey); Kragerö, Norway [c]; Nic. // Keilhauite (yellow to brown internal reflections) with oriented exsolution of rutile (light internal reflections); Kragerö, Norway [c]; Nic. +

844

Titanite A

B

250 μ

250 μ

D

C

125 μ

125 μ

845

Ilvaite (Jenite, Lievrit,Yenite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

skarn, contact metamorphic dark grey to blue-grey 5.00 - 9.50 Bireflectance: strong, orange to brown grey to blue-grey

distinct

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/C.10-Lawsonite-Ilvaite series VIII/C.10-10 Lawsonite VIII/C.10-12 Itoigawaite VIII/C.10-15 Hennomartinite VIII/C.10-17 Noelbensonite VIII/C.10-20 Ilvaite

CaAl2Si2O7(OH)2·H2O SrAl2Si2O7(OH)2·H2O SrMn2Si2O7(OH)2·H2O BaMn2(Si2O7)(OH)2·H2O CaFe2FeSi2O7O(OH)


Descriptions A Massive ilvaite (grey to blue-grey, strong bireflectance); Monte Calamita mine, Elba, Italy [c]; Nic. // B Ilvaite (strong orange to brown anisotropy); Monte Calamita mine, Elba, Italy [c]; Nic. +

846

Ilvaite A

120 μ

B

120 μ 847

Kentrolite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

inclusion in calcite of a metamorphosed stratiform Zn deposit medium grey brown 12.71 - 14.96 Bireflectance: slight light to dark greys

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/C.20-Melanotekite-Kentrolite series VIII/C.20-10 Melanotekite VIII/C.20-20 Kentrolite

Pb2Fe2Si2O9 Pb2Mn2Si2O9

222 2/m 2/m 2/m

Descriptions A Anhedral kentrolite (medium grey, slight bireflectance, particularly visible at grain boundaries), silicates (dark grey); Långban, Filipstad, Värmland, Sweden [j]; Nic. // B Kentrolite (various grey shades anisotropy, brown internal reflections), silicates (milky to bright multicolour internal reflections); Långban, Filipstad, Värmland, Sweden [j]; Nic. +

848

Kentrolite A

60 μ

B

60 μ 849

Chrysocolla (Bisbeeite) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

oxidised Cu ores dark grey bright green to turquoise [4] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/E.21-Dioptase-Chrysocolla series VIII/E.21-10 Dioptase VIII/E.21-20 Chrysocolla

CuSiO2(OH)2 (Cu,Al)2H2Si2O5(OH)4·nH2O

– 3 ortho.

Descriptions A Dense mass of crysocolla (dark grey) cut by carbonate vein (coarser anhedral grains) that also contains hematite laths (medium grey); La Negra formation, coastal Cordillera, Chile [c]; Nic. // B Dense mass of crysocolla (bright green internal reflections), carbonates (yellowish), hematite (dark; small specs of red internal reflections); La Negra formation, coastal Cordillera, Chile [c]; Nic. +

850

Chrysocolla A

120 μ

B

120 μ 851

Hedenbergite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

contact metasomatic rocks dark greys strong, colourless to green to brown [4-8] Bireflectance: distinct grey shades, anisotropy often masked by strong internal reflections

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/F.01-Pyroxene group, Clinopyroxene VIII/F.01-10 Clinoenstatite VIII/F.01-20 Clinoferrosilite VIII/F.01-30 Kanoite VIII/F.01-40 Pigeonite VIII/F.01-50 Diopside VIII/F.01-60 Hedenbergite VIII/F.01-70 Johannsenite VIII/F.01-80 Petedunnite VIII/F.01-90 Augite VIII/F.01-100 Omphacite VIII/F.01-110 Esseneite VIII/F.01-120 Spodumene VIII/F.01-130 Jadeite VIII/F.01-140 Aegirine VIII/F.01-145 Namansilite VIII/F.01-150 Jervisite VIII/F.01-160 Natalyite VIII/F.01-170 Kosmochlor

Mg2Si2O6 (Fe,Mg)2Si2O6 (Mn,Mg)2Si2O6 (Mg,Fe,Ca)(Mg,Fe)Si2O6 CaMgSi2O6 CaFeSi2O6 CaMnSi2O6 Ca(Zn,Mn,Fe,Mg)Si2O6 (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 (Ca,Na)(Mg,Fe,Al)Si2O6 CaFeAlSiO6 LiAlSi2O6 Na(Al,Fe)Si2O6 NaFeSi2O6 NaMn(Si2O6) (Na,Ca,Fe)(Sc,Mg,Fe)Si2O6 Na(V,Cr)Si2O6 NaCrSi2O6


Descriptions A Irregular mass of hedenbergite needles (medium to dark grey, bireflectance), some grains of lievrite (slightly lighter grey to bluish grey); Monte Calamita mine, Elba, Italy [c]; Nic. // B Hedenbergite needles (strong internal reflections from colourless to green to brown), lievrite (dark); Monte Calamita mine, Elba, Italy [c]; Nic. +

852

Hedenbergite A

120 μ

B

120 μ 853

Riebeckite (Crocidolite-asbestos) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

magmatic and metamorphic rocks dark grey with brownish internal reflections depending on type: orange, blue [7] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/F.08-Amphibole group, Glaucophane-Riebeckite-Kozulite series VIII/F.08-10 Glaucophane [ ]Na2(Mg3Al2)Si8O22(OH)2 VIII/F.08-20 Ferroglaucophane [ ]Na2(Fe3Al2)Si8O22(OH)2 VIII/F.08-30 Crossite Na2(Mg,Fe)3(Al,Fe)2Si8 O22(OH)2 VIII/F.08-40 Magnesioriebeckite [ ]Na2(Mg3Fe2)Si8O22(OH)2 VIII/F.08-50 Riebeckite [ ]Na2(Fe5)Si8O22(OH)2 VIII/F.08-56 Fluoronyboite Na3(Al2Mg3)(Si7Al)O22(F,OH)2 VIII/F.08-60 Nyboite Na3(Mg3Al2)Si7AlO22(OH)2 VIII/F.08-65 Ferronyboite Na3(Fe)3Al2(Si7Al)O22(OH)2 VIII/F.08-67 Ferricferronyboite Na3(Fe)3(Fe)2(Si7Al)O22(OH)2 VIII/F.08-70 Eckermannite Na3(Mg4Al)Si8O22(OH)2 VIII/F.08-80 Ferroeckermannite Na3(Fe4Al)Si8O22(OH)2 VIII/F.08-81 Ferripedrizite NaLi2(Fe2Mg2Li)Si8O22(OH)2 VIII/F.08-83 Sodicferripedrizite Na(LiNa)(Fe2Mg2Li)Si8O22(OH,F)2 VIII/F.08-84 Ferroleakeite Na3(Fe)3(Fe)2Li(Si8O22)(OH)2 VIII/F.08-85 Leakeite Na3(Mg2Fe2Li)Si8O22(OH)2 VIII/F.08-86 Fluoro-ferroleakeite Na3(Fe32Li)Si8O22F2 VIII/F.08-87 Kornite Na(CaNa)Fe4(Al,Fe)Si7AlO22(OH)2 VIII/F.08-88 Ungarettiite Na3(Mn5)Si8O22O2 VIII/F.08-89 Obertiite Na3(Mg3FeTi)Si8O22(O,F,OH)2 VIII/F.08-90 Magnesioarfvedsonite Na3(Mg4Fe)Si8O22(OH)2 VIII/F.08-92 FluoromagnesioNa3(Mg,Fe)4Fe[Si8O22](F,OH)2 arfvedsonite VIII/F.08-95 Sodic-ferriferropedrizite NaLi2(Fe5)Si8O22(OH)2 VIII/F.08-100 Arfvedsonite Na3(Fe5)Si8O22(OH)2 VIII/F.08-105 Ferriwhittakerite Na(NaLi)(Mg2Fe2Li)Si8O22(OH)2 VIII/F.08-110 Kozulite Na3Mn4(Fe,Al)Si8O22(OH)2 VIII/F.08-112 Potassicleakeite KNa2Mg2Fe2LiSi8O22(OH)2 VIII/F.08-125 Dellaventuraite Na3(Mg2,Mn,Li,Ti)Si8O22O2 VIII/F.08-157 Potassic-arfvedsonite KNa2Fe5Si8O22(OH)2

2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Fibrous riebeckite (crocidolite-asbestos) matrix (dark grey) around magnetite (brownish grey) with hematite alteration (light grey); unknown locality in Pretoria Series, Bushveld, South Africa [a]; Nic. // B Riebeckite (bright orange internal reflections), magnetite (isotropic); unknown locality in Pretoria Series, Bushveld, South Africa [a]; Nic. +

854

Riebeckite A

120 μ

B

120 μ 855

Bustamite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

high grade/temperature metamorphic Mn deposits dark grey brown to multicolour [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/F.18-Wollastonite-2M-Foshagite series VIII/F.18-10 Wollastonite-1A VIII/F.18-30 Ferrobustamite VIII/F.18-40 Bustamite VIII/F.18-50 Cascandite VIII/F.18-60 Pectolite VIII/F.18-70 Denisovite VIII/F.18-80 Serandite VIII/F.18-90 Foshagite VIII/F.18-100 Hillebrandite

CaSiO3 Ca(Fe,Ca,Mn)Si2O6 (Mn,Ca)3Si3O9 Ca(Sc,Fe)Si3O8(OH) NaCa2Si3O8(OH) (K,Na)Ca2Si3O8(F,OH) Na(Mn,Ca)2Si3O8(OH) Ca4Si3O9(OH)2 Ca6Si3O9(OH)6

– 1 – 1 – 1 – 1 – 1 mono. – 1 2/m mm2

Descriptions A Massive bustamite (dark grey, irregular fractures), pyrophanite (medium grey); Noda-Tamagawa mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. // B Bustamite (brown and multicolour internal reflections), pyrophanite (dark grey); Noda-Tamagawa mine, Iwate Prefecture, Honshu Island, Japan [j]; Nic. +

856

Bustamite A

120 μ

B

120 μ 857

Rhodonite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

hydrothermal, metamorphic, metasomatic dark grey orange to pinkish red [5] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/F.27-Rhodonite-Inesite series VIII/F.27-10 Rhodonite VIII/F.27-20 Babingtonite VIII/F.27-30 Manganbabingtonite VIII/F.27-35 Scandiobabingtonite VIII/F.27-40 Santaclaraite VIII/F.27-50 Nambulite VIII/F.27-60 Natronambulite VIII/F.27-70 Lithiomarsturite VIII/F.27-80 Marsturite VIII/F.27-90 Inesite

(Mn,Fe,Mg,Ca)SiO3 Ca2(Fe,Mn)FeSi5O14(OH) Ca2(Mn,Fe)FeSi5O14(OH) Ca2(Fe,Mn)ScSi5O14(OH) CaMn4Si5O14(OH)2·H2O (Li,Na)Mn4[Si5O14(OH)] (Na,Li)Mn4[Si5O14(OH)] LiCa2Mn2HSi5O15 NaCaMn3[Si5O14(OH)] Ca2Mn7Si10O28(OH)2·5H2O

– 1 – 1 – 1 – 1 – 1 – 1 – 1 – 1 tri. – 1

Descriptions A Anhedral rhodonite (dark grey, irregular cracks), alabandite (medium grey), pyrophanite (small grain in rhodonite, colour slightly darker than alabandite), pyrite (white), pyrrhotite (cream tint); Hata Mine, Iwate, Japan [c]; Nic. // B Rhodonite (pink to multicolour internal reflections), alabandite (dark), pyrophanite (dark brown internal reflections), pyrite (dark), pyrrhotite (slightly lighter than alabandite); Hata Mine, Iwate, Japan [c]; Nic. +

858

Rhodonite A

60 μ

B

60 μ 859

Muscovite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

igneous rocks, pegmatites, metamorphics dark grey light grey to colourless, yellowish [4] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/H.10-Mica group, Muscovite series VIII/H.10-10 Aluminoceladonite VIII/H.10-20 Ferro-aluminoceladonite VIII/H.10-30 Celadonite VIII/H.10-35 Chromceladonite VIII/H.10-40 Ferroceladonite VIII/H.10-50 Paragonite VIII/H.10-60 Boromuscovite VIII/H.10-70 Muscovite VIII/H.10-80 Chromphyllite VIII/H.10-90 Roscoelite VIII/H.10-95 Ganterite VIII/H.10-100 Tobelite VIII/H.10-110 Nanpingite

A B

C D E

KAl(Mg,Fe)[ ]Si4O10(OH)2 K2Fe2Al2Si8O20(OH)4 K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 KCrMg(Si4O10)(OH)2 K2FeFeSi8O20(OH)4 NaAl2(Si3Al)O10(OH)2 KAl2(Si3B)O10(OH,F)2 KAl2(Si3Al)O10(OH,F)2 (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 K(V,Al,Mg)2AlSi3O10(OH)2 [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10)(OH)2 (NH4,K)Al2(Si3Al)O10(OH)2 Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2

2/m 2/m 2/m 2 2/m mono. 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions Subhedral muscovite (dark grey, cleavage), pyrite (yellowish), sphalerite (medium grey), pyrrhotite (brownish tint), galena (light grey); Bleikvassli Mine, Hemnes, Norway [a]; Nic. // Muscovite (diffuse multicolour internal reflections), pyrite (isotropic, brownish grey), sphalerite (isotropic, red brown internal reflections), pyrrhotite (brownish grey anisotropy), galena (isotropic, bluish grey); Bleikvassli Mine, Hemnes, Norway [a]; Nic. + Muscovite (dark grey) is replaced along cleavage by galena (light grey) and chalcopyrite (yellow); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // Muscovite (grey, with multicolour reflections) cut sub-parallel to cleavage, inclusion of another silicate; Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // Muscovite (grey, with multicolour reflections) cut sub-parallel to cleavage; Black Mountain Mine, Aggeneys, South Africa [c]; Nic. +

860

Muscovite A

60 μ

C

B

125 μ

96 μ

D

E

250 μ

250 μ 861

Biotite Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

igneous rocks, pegmatites, metamorphics dark grey brown [4] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/H.11-Mica group, Biotite series VIII/H.11-00 Biotite VIII/H.11-00* Zinnwaldite VIII/H.11-10 Polylithionite VIII/H.11-20 Tainiolite VIII/H.11-30 Norrishite VIII/H.11-35 Shirokshinite VIII/H.11-40 Montdorite VIII/H.11-50 Trilithionite VIII/H.11-60 Masutomilite VIII/H.11-70 Aspidolite VIII/H.11-80 Phlogopite VIII/H.11-90 Tetra-ferriphlogopite VIII/H.11-100 Hendricksite VIII/H.11-102 Shirozulite VIII/H.11-105 Fluorannite VIII/H.11-110 Annite VIII/H.11-120 Tetra-ferri-annite VIII/H.11-130 Ephesite VIII/H.11-140 Preiswerkite VIII/H.11-150 Eastonite VIII/H.11-160 Siderophyllite

K(Mg,Fe)3[AlSi3O10(OH,F)2 KLiFeAl(AlSi3)O10(F,OH)2 KLi2AlSi4O10(F,OH)2 KLiMg2Si4O10F2 K(Mn2Li)Si4O10(O)2 K(NaMg2)Si4O10F2 (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 KLi1.5Al1.5AlSi3O10F2 K(Li,Al,Mn)3[(Si,Al)4O10](F,OH)2 NaMg3AlSi3O10(OH)2 KMg3(Si3Al)O10(F,OH)2 KMg3FeSi3O10(OH)2 K(Zn,Mg,Mn)3Si3AlO10(OH)2 KMn3(AlSi3)O10(OH,F)2 KFe3AlSi3O10F2 KFe3AlSi3O10(OH,F)2 K(Fe,Mg)3(Fe,Al)Si3O10(OH)2 NaLiAl2(Al2Si2)O10(OH)2 NaMg2Al3Si2O10(OH)2 KMg2Al[Al2Si2O10](OH)2 KFe2Al(Al2Si2)O10(F,OH)2

C2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m 2/m

Descriptions A Biotite (dark grey, slightly lighter than surrounding silicates) with rutile (light grey specs) oriented along cleavage of biotite, pyrite (cream); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. // B Biotite (dark and medium brown anisotropy and internal reflections), rutile (white internal reflections), pyrite (greenish grey, isotropic); Black Mountain Mine, Aggeneys, South Africa [c]; Nic. +

862

Biotite A

60 μ

B

60 μ 863

Chamosite (Brunsvigite, Daphnite, Delessite, Thuringite (Fe)) Geologic Environment: Reflection Colour: Internal Reflections: Reflectance [%]: Anisotropy: Pleochroism:

metamorphosed iron deposits dark grey blue-green [8] Bireflectance:

Strunz Classification - Group Members - Chemical Formula - Crystallography VIII/H.23-Chlorite group VIII/H.23-10 Sudoite VIII/H.23-20 Clinochlore VIII/H.23-30 Chamosite VIII/H.23-40 Orthochamosite VIII/H.23-50 Baileychlore VIII/H.23-60 Pennantite VIII/H.23-70 Nimite VIII/H.23-80 Gonyerite VIII/H.23-90 Cookeite VIII/H.23-95 Borocookeite VIII/H.23-100 Manandonite VIII/H.23-110 Franklinfurnaceite

Mg2(Al,Fe)3Si3AlO10(OH)8 (Mg,Fe)5Al(Si3Al)O10(OH)8 (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 (Fe,Mg,Fe)5Al(Si3Al)O10(OH,O)8 (Zn,Al,[ ])3[Fe2Al][Si3AlO10](OH)8 Mn5Al(Si3Al)O10(OH)8 (Ni,Mg,Fe)5Al(Si3Al)O10(OH)8 Mn3[Mn3Fe][(Si,Fe)4O10](OH,O)8 LiAl4(Si3Al)O10(OH)8 Li(1+3x)Al(4-x)(BSi3)O10(OH,F)8 Li2Al4[(Si2AlB)O10](OH)8 Ca2(Fe,Al)Mn4Zn2Si2O10(OH)8

2/m 2/m 2/m ortho. tri. 2/m 2/m ortho. 2/m 2/m 1 2

Descriptions A Hypidiomorphic chamosite (medium grey with slight greenish tint) next to Fe ooliths (partially brighter grey and faint brown internal reflections); La Paix mine, Alsace, France [b]; Nic. // B Chamosite (dark green internal reflections), Fe ooliths (brown internal reflections); La Paix mine, Alsace, France [b]; Nic. +

864

Chamosite A

60 μ

B

60 μ 865


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Lawrence, L.J. (1998). Gold, sulphides and other primary minerals. Australian Journal of Mineralogy, 4(2): 93-99. Leydet, J.C. (2006). Shinkolobwe (République Démocratique du Congo). Le Cahier des Micromonteurs, 93: 86-88. Lhoest, J.J. (1995). Famous mineral localities: The Kipushi mine (Zaire). Mineralogical Record, 26(3): 163-192. Lombaard, A.F. (1986). The copper deposits of the Okiep district, Namaqualand. In: C.R. Anhaeusser and S. Maske (Editors), Mineral Deposits of Southern Africa, 1421-1445. Makeyev, A., Bryanchaninova, N., and Kostoyanov, A. (1999). Rhenium-osmium age of PGM from the alluvium of the North Urals and Timans, Russia, EUG 10. Electronic conference abstracts of session H03:3B, Genesis of platinum-group element (PGE) sulphide deposits. Cambridge Publications, Strasbourg. Martin, M., Schlegel, F., and Siemroth, J. (1994). Das Bergbaurevier Niederschlag bei Oberwiesenthal: Seltene Kupferarsenate aus dem Sächsischen Erzgebirge. Lapis, 19(4): 13-22. Mücke, A. (1989). Anleitung zur Erzmikroskopie mit einer Einführung in die Erzpetrographie. Enke Verlag, Stuttgart, pp. 187. Mücke, A., Dzigbodi-Adjimah, K., and Annor, A. (1999). Mineralogy, petrology, geochemistry and genesis of the Paleoproterozoic Birimian manganese-formation of Nsuta/Ghana. Mineral. Deposita, 34: 297-311. Naldrett, A.J. (2005). A history of our understanding of magmatic Ni-Cu sulfide deposits. Canadian Mineralogist, 43: 2069-2098. Nysten, P., Holtstam, D., and Jonsson, E. (Editors) (1999). The Långban minerals. Långban - The mines, their minerals, geology and explorers. Swedish Museum of Natural History and Raster Förlag, Chr. Weise Verlag, Stockholm & Munich, 89-183. Oelsner, O. (1960). Atlas der wichtigsten Mineralparagenesen im mikroskopischen Bild. VEB Deutscher Verlag der Wissenschaften, Berlin, pp. 309. Ondruš, P., Veselovský, F., Skála, R., Císarová, I., Hloušek, J., Frýda, J., Vavrín, I., ejka, J., and Gabašová, A. (1997). New naturally occurring phases of secondary origin from Jáchymov (Joachimstal). Journal of the Czech Geological Society, 42: 7-107. Parafiniuk, J. and Domanska, J. (2002). Bismuth minerals from Redziny (Rudawy Janowickie, SW Poland). Mineralogia Polonica, 33(2): 3-14. Pauliš, P. and Haake, R. (1991). Die Mineralien der Skarn-Lagerstätte Medenec im Erzgebirge/ CSFR. Mineralien-Welt, 2(5): 19-29. Pawlowski, D. (1991). Mineralfundstellen im Sauerland, Chr. Weise Verlag. Chr. Weise Verlag, Munich, pp. 104. Ramdohr, P. (1969). The ore minerals and their intergrowths. Akademie-Verlag, Berlin, 1174 pp. Rieck, B. (1993). Famous mineral localities: Allchar, Macedonia. Mineralogical Record, 24(6): 437449. Rösler, H.J. (1991). Lehrbuch der Mineralogie. Deutscher Verlag für Grundstoffindustrie, Leipzig, pp. 844. Sejkora, J. and Tvrdý, J. (2002). Die primäre Mineralisation der Lagerstätte Jáchymov und ihre interessantesten Mineralien. Lapis, 27(7-8): 31-43. Shiga, Y. (1987). Behavior of iron, nickel, cobalt and sulfur during serpentinization, with reference to Hayachine ultramafic rocks of the Kamaishi mining district, northeastern Japan. Canadian Mineralogist, 25: 611-624. Sokatsch, J. and Weiss, S. (2001). Zinnbergbau in Altenberg/Sachsen. Lapis, 26(2): 13–25. Stahle, V., Koch, M., McCammon, C.A., Mann, U., and Markl, G. (2002). Occurrence of low-Ti and high-Ti freudenbergite in alkali syenite dikes from the Katzenbuckel volcano, southwestern Germany. Canadian Mineralogist, 40: 1609-1627. Stekhin, A.I. (1994). Mineralogical and geochemical characteristics of the Cu-Ni ores of the Oktyabr'sky and Talnakh deposits. In: P.C. Lightfoot, A.J. Naldrett and P. Sheahan (Editors), Proceedings of the Sudbury-Noril'sk Symposium. Ontario Geological Survey, 217-230. Strunz, H. (2001). Mineralogical Tables. E.Schweizerbart'sche Verlagsbuchhandlung, Science Publishers, Stuttgart, pp. 870. Strunz, H., Geier, B.H., and Seeliger, E. (1958). Gallite, CuGaS2, das erste selbständige Galliummineral, und seine Verbreitung in den Erzen der Tsumeb- und Kipushi-Mine. Neues Jahrbuch für Mineralogie, Monatshefte: 241-264. Szentpéteri, K., Watkinson, D.H., Molnár, F., and Jones, P.C. (1999). PGE minerals and the paragenesis of Ni-Cu ores from Copper Cliff Offset, Copper Cliff North Mining Area, Sudbury, Canada, EUG 10. Electronic conference abstracts of session H03:3B, Genesis of platinum-group element (PGE) sulphide deposits. Cambridge Publications, Strasbourg. Torgashin, A.S. (1994). Geology of the massive and copper ores of the western part of the Oktyabr'sky deposit. In: P.C. Lightfoot, A.J. Naldrett, and P. Sheahan (Editors), Proceedings of the Sudbury-Noril'sk Symposium. Ontario Geological Survey, 231-241. 868

Torres-Ruiz, J., Garuti, G., Gazzotti, M., Gervilla, F., and Hach-Alí, P.F. (1996). Platinum-group minerals in chromitites from the Ojen Iherzolite massif (Serrania de Ronda), Betic Cordillera, southern Spain. Mineralogy and Petrology, 56: 25-50. Walenta, K. (1992). Die Mineralien des Schwarzwaldes. Chr. Weise Verlag, Munich, pp. 335. Watanabe, T. (1959). The minerals of the Noda-Tamagawa mine, Iwate prefecture, Japan; I. Notes on geology and paragenesis of minerals. Mineralogical Journal, 2(6): 408-421. Watanabe, T., Kato, A., and Ito, J. (1960). The minerals of the Noda-Tamagawa mine, Iwate Prefecture, Japan; II. Pyrochroite ore (Kimiman-koo) and its origin. Mineralogical Journal, 3(1): 3041. Watkinson, D. (1999). PGE Enrichment in Cu-Ni-Rich Sulfide Deposits: Examples from the footwall of the Sudbury Igneous Complex, Canada, EUG 10. Electronic conference abstracts of session H03:3B, Genesis of platinum-group element (PGE) sulphide deposits. Cambridge Publications, Strasbourg. Weiß, S. (1990). Mineralfundstellen, Deutschland West. Chr. Weise Verlag, Munich. Whitehead, W.L. (1919). The veins of Chanarcillo, Chile. Econ. Geol., 14: 1-45. Wilson, E.D. (1950a). Arizona zinc and lead deposits, part I. AZ Bur. Mines Bull., 156: 96-98. Wilson, E.D. (1950b). Arizona zinc and lead deposits, part II. AZ Bur. Mines Bull., 158. Wittern, A. (2001). Mineralfundorte in Deutschland, 137. Schweizerbart, Stuttgart, 162-163.

869

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870

Mineral Index The following mineral index marks the main mineral names (bold) and synomyms (italic), which are mentioned in the tables and figure captions. In several cases, synonyms point to more than one mineral (e.g., Coltan for Ferrocolumbite and Ferrotantalite). Although this might seem confusing, it reflects the pertaining literature and was, thus, not omitted.

A Acanthite Acicular Iron Ore Aikinite Akrusite Alabandite Algodonite Allophytin Almandine Altaite Aluminium Amalgam Amoibite amorphous MoS2 Anatase Andorite Anglarite Anglesite Anhydrite Anilite Annabergite Antimonite Antimonsilver Antimony Antimony Bloom Antimony Enargite Antimony Glance Antimony Glance Ore Antimony Nickel Glance Antitaenite Antunezite Aphtonite Aramayoite Argentite Argentobismutite Argentopyrite Argyrite Argyro-Pyrrhotite Argyroceratite Argyrodite Argyrojodite Armalcolite Arsenic Arsenical Nickel Arsenical Pyrite Arsenoferrite Arsenolamprite Arsenopalladinite Arsenopyrite Arsenosiderite Atacamite Atokite

140 736 526 772 256 92 746 832 262 14 12 408 444 708 516 458 794 790 122 826 350 96 78 628 206 350 508 410 24 796 236 266 138 268 250 138 248 572 156 574 670 76 288 428 434 82 100 428 434 580 60

Brazilite 726 Breislakite 786 Breithauptite 290 Briartite 210 Brittle Silver Ore 468 Brongniardite 156, 496 Brown Manganese Ore 740 Brunsvigite 864 726 Bunsenine 376 792 Bustamite 856 792 560 518 C 526 Cabriite 72 448 Cadmium 16 458 Cajuelite 678 492 Calaverite 378 128 Calcite 766 124 Calcium Sulfate 790 416 Calcium Tungstate 804 666 Calomel 576 230 Calvonigrit 682 862 Canfieldite 158 754 Cannizarite 544 850 Carlsbergite 30 630 Carrollite 324 80 Cassiterite 684 352 Cassiterolamprite 214 352 Cattierite 384 352 Cerargyrite 572 632 Cerussite 772 540 Chalco-Lamprite 668 590 Chalcocite 116 390 Chalcomenite 764 390 Chalcomicline 126 256 Chalcophanite 752 26 Chalcopyrite 190 246 258 Chalcopyrrhotite 462 502 Chalcostibite 582 748 Chalcotrichite 246 796 Chalmersite 768 334 Chalybite 862 364 Chamosite 458 126 Chazellite 298 144 Cherepanovite 774 504 Chessylite 810 492 Chinoite 456 346 Chloanthite 572 316 Chlorargyrite 580 720 Chlorochalcite 614 840 Chromeferrite 614 570 Chromite 10 398 606 26 774

Auricupride Aurostibite Automolite Awaruite Azurite B Baddeleyite Barite Baroselenite Bartonite Baumhauerite Belonite Berndtite Berthierite Berthonite Berzelianite Betekhtinite Binarite Bindheimite Binnite Biotite Birnessite Bisbeeite Bismite Bismuth Bismuth Glance Bismuthinite Bismutolamprite Bixbyite Bjelkite Black Copper Oxide Blackeite Blockite Blumbachite Bobrovskite Boleslavite Bolidenite Boodtite Borgströmite Bornhardtite Bornine Bornite Botesite Boulangerite Bournonite Bowieite Braggite Brannerite Braunite Bravoite 871

Chrysocolla 850 Dufrenoysite Chrysolite 830 Duftite Chrysomelane 602 Dyscrasite Cinabre 280 Dzhalindite Cinnabar 280 Cinnabarite 280 Clausthalite 260 E Cobaltine 406 Edgarite Cobaltite 406 Edisonite Coffinite 836 Edwarsite Cohenite 28 Eisen Coloradoite 186 Electrum Coltan 716, 718 Emilite Columbite 716 Emplectite Colusite 226 Enargite Comuccite 512 Endeiolite Cooperite 318 Endellionite Copper 4 Endlichite (As) Coppite 232 Erdite Cordobaite 720 Eremite Coronadite 696 Erlichmanite Corundum 634 Erubescite Cosalite 540 Erythrine Covelline 302 Erythroconite Covellite 302 Eskebornite Crednerite 596 Eskolaite Crocidolite-asbestos 854 Eucairite Crocoite 800 Eutomite Cronusite 564 Crookesite 130 F Cryptomelane 692 Cubanite 246 Falkmanite Cuivre 4 False Galena Cupreine 116 Famatinite Cuprite 582 Fayalite Cuproiridsite 340 Fe-Wolframite Cuprorhodsite 338 Feitknechtite Cylindrite 278 Felbertalite Cyprargyrite 148 Ferberite Cyprusite 796 Ferro-Plumbite Ferro-Spinell Ferrocolumbite Ferroselite D Daphnite 864 Ferrotantalite Daphyllite 364 Fersilicite Dark Red Silver Ore 472 Ferutite Darwinite 92 Fieldite Daubreelite 332 Fischesserite Davidite-(Ce, La, Y) 658 Fluor Spar Defernite 778 Fluorite Delafossite 594 Folgerite Delatoreite 698 Fool’s Gold Delessite 864 Foordite Delislite 494 Forsterite Descloizite 814 Franckeite Dialogite 770 Franklinite Dianite 716 Freboldite Diaphorite 496 Fredericite Digenite 120 Freibergite Djerfisherite 556 Freieslebenite Djurleite 118 Frenzelite Dobschauite 408 Frohbergite Domeykite 94 Froodite 872

G 500 812 Gahnite 96 Gahnospinell 760 Galaxite Galena Galenobismuthite Gallite 348 Gallitzinite 678 Garbyite 808 Gaudefroyite 20 Geikielite 8 Geocronite 528 Germanite 464 Gersdorffite 244 Geversite 668 Glaucodot 492 Glaukopyrite 820 Godlevskite 566 Goethite 808 Gold 394 Goldfieldite 126 Goldglätte 824 Gorlandite 230 Gotthardite 192 Graphite 638 Gratonite 150 Greenockite 364 Gregorite Grey Nickel Pyrite Grothite Groutite 502 Gruetite 178 Grünlingite 206 Guanajuatite 830 Guayacanite 714 Gudmundite 744 Guejarite 546 Gupeiite 714 Guyanaite 654 Gypsum 602 716 418 H 718 Hair Pyrite 40 Hartmannite 658 Hastite 232 Hauchecornite 152 Hauerite 578 Hausmannite 578 Heavy Spar 170 Heazlewoodite 382 Hedenbergite 722 Hematite 830 Hemichalcite 276 Hengleinite 612 Henritermierite 292 Hercynite 230 Hermesite 236 Herzenbergite 494 Hessite 354 Hetaerolite 422 Hetairite 426 Heteroclase

606 606 604 258 548 196 678 244 788 642 484 224 408 400 430 434 176 736 8 238 598 818 500 84 486 242 644 408 844 742 366 366 354 244 432 462 36 750 798

300 290 420 168 388 618 792 164 852 636 464 570 834 602 234 270 144 620 620, 622 840

Heterogenite Heteromorphite Hexaferrum Hexastannine Hexastannite Hoffmannite Hogbomite Högbomite Hollandite Hollingworthite Hongshiite Horn Quicksilver Horn Silver Hübnerite Huebnerite Hulsite Hutchinsonite Hüttenbergite Hydro-Cervantite Hydrofranklinite Hydrohausmannite Hydrohetaerolite Hypotyphite

748 508 42 218 218 434 650 650 694 412 54 576 572 712 712 782 478 434 664 752 744 622 82

I Idaite Ildefonsite Ilmenite Ilmenorutile Ilvaite Indite Insizwaite Iodargyrite Irarsite Iridium Iridosmine Iron Iron Spar Iron Spinell Isocubanite Isoferroplatinum Isomertieite Isostannite

306 718 644 688 846 330 402 574 414 50 44 20 768 602 200 56 102 216

J Jacobsite Jalpaite Jamesonite Jarosite Jenite Jimboite Jodargyrite Jodite Jodyrite Jordanite Jordisite Joséite Josephinite Julianite

610 146 512 796 846 780 574 574 574 482 444 366 26 230

K Kamacite Karelianite Kashinite Keeleyite Keilhauite Kennedyite Kentrolite Kerargyrite Kermesite Kesterite Kidney Ore Kilbrickenite Kirchite Klockmannite Kobellite Koboldine Kolbeckine Kolosorukite Kongsbergite Kösterite Krennerite Krupkaite Kupfer Kusterite

22 640 344 524 844 670 848 572 568 214 636 484 728 304 538 320 270 796 12 214 376 532 4 214

L Lamprite Laurite Lautite Lead Lead Glanc Lead Monoxide Lead Spar Lead Vitriol Lehmannite Lenaite Lepidocrocite Lepidolamprite Lerbachite Leukargyrite Leukopyrite Libethenite Lievrit Light Red Silver Ore Lillhammerite Lillianite Limonite Lindstroemite Lindströmite Linnaeite Linneite Litharge Lithiophorite Lodochnikite Lodochnikovite Loellingite Löllingite Lorandite Loveringite

34 392 188 18 258 600 794 794 800 194 738 276 260 236 434 810 846 470 170 536 736 530 530 320 320 598 746 720 720 434 434 480 656

873

Ludwigite Luzonite

784 204

M Macedonite 662 Mackinawite 174 Maghaemite 648 Maghemite 648 Magnetic Iron Ore 608 Magnetite 608 Magnetoplumbite 652 Magnetopyrite 284 Malachite 776 Malanite 342 Manganblende 256 Manganese Spar 770 Manganite 740 Mangano-Wolframite 712 Manganosite 588 Marcasite 416 Marokite 624 Martite 636 Martourite 458 Massicot 600 Matildite 268 Mattagamite 424 Maucherite 98 Mavidzite 658 Mawsonite 220 Mechernichite 570 Megabasite 712 Melakonite 468, 590 Melanoconite 590 Melanovanadite 762 Melonite 450 Menaccanite 644 Meneghinite 488 Mercurian Tetrahedrite 234 Mercury Silver 12 Metacinnabar 180 Miargyrite 264 Miassite 172 Millerite 300 Mimetite 818 Mindigite 748 Minium 626 Mo-ochre 732 Mock Lead Ore 178 Modumite 454 Moffrasite 666 Mohsine 434 Molybdenite 442 Molybdite 732 Monazite 808 Monazitoide 808 Moncheite 452 Monimolite 666 Montbrayite 370 Morocochite 268 Moronolite 796

Mullanite Müllerine Muscovite N Nagyagite Naumannite Needle Ironstone Neltnerite Neodigenite Nepalite Nevyanakite Niccolite Nickel Bloom Nickel Bournonite Nickel Glance Nickel-Linneite Nickel-Skutterudite Nickelian Pyrite Nickeline Nicopyrite Niggliite Niningerite Niobite Nsutite O Octahedrite Oldhamite Olivine Onofrite Orange Bornite Oregonite Orickite Oro Orpiment Oruetite Osmium Ottemannite Oulankite Oulongaite Owyheeite P Paarite Padmaite Paigeite Palarstanide Palladodymite Paolovite Paracolumbit Paraguanajuatite Paramelaconite Pararammelsbergite Paratacamite Paratenorite Parkerite Partschite Pastreite Patrinite Patronite

504 Pb-Bismutite 376 Pennroseit 860 Pentlandite Peridote Permingeatite Perovskite 372 Peruvite 142 Petterdite 736 Petzite 842 Pharmakopyrite 120 Phosphocerite 232 Phosphomimetite 44 Pilsenite 288 Pitch Blende 826 Placodine (industrial) 410 Plagionite 408 Platinum 322 Plattnerite 456 Plumbobinnite 570 Plumboferrite 288 Plumbopalladinite 170 Plumbum 62 Plumosite 252 Poikilite 716 Polarite 706 Polianite Poliopyrite, Poly-Rutile Polybasite 708 Polydymite 254 Polytelite 830 Polyxen 180 Prassoite 222 Proustite 166 Pseudobrookite 202 Psilomelane 8 Pyrantimonite 554 Pyrargyrite 366 Pyrite 44 Pyrochlore 356 Pyrochroite 112 Pyrolusite 112 Pyromorphite 498 Pyrophanite Pyrosiderite Pyrrhosiderite Pyrrhotite 534 404 Q 786 66 Quartz 106 Quenselite 70 644 R 362 592 Radial Blende 440 Raimondite 580 Ramdohrite 592 Ramirit 162 Rammelsbergite 34 Ramsdellite 796 Rasvumite 526 Rathite 550 Realgar 874

540 390 170 830 208 660 268 818 154 434 808 816 368 728 98 510 52 686 500 654 68 18 504 126 294 682 416 690 466 322 236 52 172 470 672 702 568 472 382 668 734 680 816 646 736 736 284

674 756

240 796 514 814 438 704 558 520 552

Red Antimony Ore Red Lead Ore Red Oxide of Lead Red Zinc Oxide Redruthite Regnolite Reitingerite Remolinite Renierite Reniforite Rhabdite Rhodarsenide Rhodochrosite Rhodoite Rhodonite Rickardite Riebeckite Rittingerite Romanéchite Roquesite Rosenite Rosite Ruby Iron Ruby Mica Ruby Red Silver Ore Ruby Silver Ore Rumongite Rutheniridosmine Rutheniridosmium Ruthenium Rutile

568 800 626 584 116 230 726 580 222 482 34 108 770 824 858 136 854 474 702 198 510 462 738 738 472 470 688 48 44 46 678

S Safflorite Sagenite Sahlinite Sakuraiite Samsonite Sanfordite Sartorite Sätersbergite Satin Spar Saukovite Savodinskite Schapbachite Scheelite Schoellhornite Schöllhornite Schreibersite Schulzite Schwazite Selenite Selenium Selenmercury Selenocupride Seligmannite Semseyite Shandite Siderite Siderochrome Siegenite Silica, amorphous Silvan

436 678 822 216 476 136 522 434 798 180 144 268 804 562 562 34 484 234 798 88 184 128 490 506 160 768 614 328 676 90

Silver Silver Amalgam Silver Glance Silver Jamesonite Sinoite Siserskite Sitaparite Skogbölite Skorian Skutterudite Smaltite Smythite Sobolevskite Söhngeite Sommarugaite Sosmanite Souesite Spaniolite Spartalite Spathose Iron Specularite Sperrylite Sphalerite Sphene Stainierite Stanierite Stanniolite Stannite Stannoidite Stannolite Stannopalladinite Stephanite Sternbergite Stibiconite Stibioargentite Stibiogalenite Stibiolite Stibioluzonite Stibiopalladinite Stibium Stibnite Stilleite Stirian Stistaite Stromeyerite Stylopite Sulfur Sulrhodite Sulvanite Sundite Sylvanite Synchnodymite

6 12 138, 140 498 32 44 632 690 602 454 454 286 296 758 408 648 26 234 584 768 636 396 178 844 748 748 684 212 218 684 64 468 248 664 96 666 664 206 104 78 350 182 408 272 148 232 86 346 228 516 374 324

T Taenite Taimyrite Tammela-Tantalite Tannenite Taosite

24 74 690 464 650

Tapiolite Teallite Telargpalite Tellurantimony Telluric Silver Glance Tellurium Tellurobismutite Temagamite Temiskamite Tennantite Tenorite Termanite Tetradymite Tetrahedrite Thalheimite Thoreaulite Thucholite Thuenite Thuringite (Fe) Tiemannite Tilkerodite Tin Ore Titanic Iron Ore Titanite Titanoferrite Tochilinite Todorokite Topaz Torwanite Transvaalite Tremenbeerite Trieuite Trimontite Tritochlorite Troilite Troostite Tulameenite Tungstein Tungstenite Tyrrelite

690 274 110 358 144 90 360 114 98 230 590 464 364 232 428 724 730 644 864 184 260 684 644 844 644 310 698 838 190 748 84 748 804 814 282 828 58 804 446 336

Vauquelinite Villamaninite Violarite Volgerite Vonsenite Vulcanite Vyalsovite

802 380 326 664 786 314 312

Xanthoconite Xanthosiderite Xaphyllite Xifengite

474 736 364 38

658 410 728 616 616 616 132 728 808 796

Y Yellow Lead Ore Yenite Yokosukaite Yttro-titanite

806 846 706 844

W Wad 680, 706 Walleriite 308 Washingtonite 644 Webnerite 516 Wehrlite (mixture of Pilsenite and Hessite) 368 Weibullite 542 Weissite 134 White Lead Ore 772 Whitmanite 642 Whitneyite 92 Willemite 828 Wiltshireite 520 Wittichenite 460 Wolframite 710 Wolfsbergite 462, 512 Wolftonite 620, 622 Wolnyn 792 Wood Tin 684 Woodruffite 700 Wuestite 586 Wulfenite 806 Wurtzite 240 Wüstite 586 X

U Ufertite Ullmannite Ulrichite Ulvite Ulvospinell Ulvöspinell Umangite Uraninite Urdite Utahite V 386 628 308 820

Vaesite Valentinite Valleriite Vanadinite

875

Z Zinc Spinell Zinc-Hausmannite Zincite Zinckenite Zincoferrite Zincselenide Zinkenite Zinnober Zorgite

606 620, 622 584 524 612 182 524 280 260


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