1267:
352:
723:
282:
661:
438:
529:
401:
170:
203:
617:
574:
114:
491:
319:
237:
714:
is the 'play' or 'fire' of rainbow-coloured light caused by very thin regular structures or layers beneath the surface of a gemstone. Similar to a thin film of oil on water, these layers interfere with the rays of reflected light, reinforcing some colours and cancelling others. Iridescence is seen at
93:
Lustre varies over a wide continuum, and so there are no rigid boundaries between the different types of lustre. (For this reason, different sources can often describe the same mineral differently. This ambiguity is further complicated by lustre's ability to vary widely within a particular mineral
636:
minerals display luminous bands, which appear to move as the specimen is rotated. Such minerals are composed of parallel fibers (or contain fibrous voids or inclusions), which reflect light into a direction perpendicular to their orientation, thus forming narrow bands of light. The most famous
702:
in Russia is green by daylight and red by incandescent light. Other varieties of alexandrite may be yellowish or pink in daylight and a columbine or raspberry red by incandescent light. The optimum or "ideal" colour change would be fine emerald green to fine purplish red, but this is rare.
1190:
698:. The gem results from small-scale replacement of aluminium by chromium oxide, which is responsible for alexandrite's characteristic green to red colour change. Alexandrite from the
601:. It arises from minute, preferentially oriented mineral platelets within the material. These platelets are so numerous that they also influence the material's body colour. In
418:
minerals have similar lustre to metal, but are duller and less reflective. A submetallic lustre often occurs in near-opaque minerals with very high refractive indices, such as
463:.) This type of lustre is one of the most commonly seen, and occurs in transparent or translucent minerals with relatively low refractive indices. Common examples include
37:
221:
minerals resemble fat or grease. A greasy lustre often occurs in minerals containing a great abundance of microscopic inclusions, with examples including
1197:
1140:
199:. A distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, and having even less lustre.
891:
1019:
94:
species). The terms are frequently combined to describe intermediate types of lustre (for example, a "vitreous greasy" lustre).
1163:
299:
minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of
744:
originating from below the surface of a stone that occurs when light is reflected between layers of minerals. It is seen in
105:(the display of luminous bands, which appear to move as the specimen is rotated). A list of such phenomena is given below.
191:) minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, approximating a
1116:
1091:
1062:
875:
830:
792:
784:
1183:
1242:
373:
minerals have a parallel arrangement of extremely fine fibres, giving them a lustre reminiscent of
1083:
139:(of 1.9 or more). Minerals with a true adamantine lustre are uncommon, with examples including
1206:
192:
1232:
682:
gemstones. Other gems also occur in colour-change varieties, including (but not limited to)
745:
650:
542:
263:
98:
8:
1291:
1252:
895:
1217:
1134:
1054:
1023:
304:
154:
Minerals with a lesser (but still relatively high) degree of lustre are referred to as
1159:
1122:
1112:
1087:
1058:
871:
826:
788:
1247:
646:
642:
136:
33:
1271:
979:
846:
25:
1227:
757:
699:
694:. Alexandrite displays a colour change dependent upon light, along with strong
638:
620:
589:
148:
45:
892:"Emporia State University: GO 340 Gemstones & Gemology: Visual Properties"
1285:
1222:
1126:
956:
753:
259:
351:
936:
916:
59:, meaning "light", and generally implies radiance, gloss, or brilliance.
16:
Manner in which light interacts with a crystal, rock, or mineral's surface
1175:
999:
749:
741:
726:
722:
695:
679:
664:
341:
117:
660:
654:
632:
610:
602:
577:
517:
480:
427:
419:
404:
386:
355:
281:
226:
102:
437:
308:
285:
275:
233:. Many minerals with a greasy lustre also feel greasy to the touch.
196:
173:
140:
131:
minerals possess a superlative lustre, which is most notably seen in
90:) refers to a glassy lustre. A list of these terms is given below.
683:
606:
563:
547:
546:
is the display of a star-shaped luminous area. It is seen in some
484:
423:
378:
312:
163:
1020:"Emporia State University: GO 340 Gemstones & Gemology: Jade"
598:
464:
431:
382:
230:
132:
49:
41:
135:. Such minerals are transparent or translucent, and have a high
691:
687:
567:
559:
555:
528:
468:
441:
390:
359:
271:
267:
240:
159:
144:
400:
169:
616:
573:
476:
472:
456:
345:
337:
322:
300:
202:
113:
83:
53:
490:
716:
551:
513:
494:
374:
318:
236:
222:
207:
645:, but the effect may also occur in other minerals such as
509:
97:
Some minerals exhibit unusual optical phenomena, such as
820:
258:) minerals have the lustre of polished metal, and with
1080:
Nature's
Building Blocks: An A-Z Guide to the Elements
62:
A range of terms are used to describe lustre, such as
344:
or (smooth-surfaced) plastic. A principal example is
678:
is most commonly found in alexandrite, a variety of
1071:
949:
839:
40:) is the way light interacts with the surface of a
1153:
459:. (The term is derived from the Latin for glass,
1283:
992:
929:
909:
101:(the display of a star-shaped luminous area) or
1044:
1042:
1040:
974:
972:
740:(German, literally "shimmer"), is the metallic
397:lustre is similar, but has a coarser texture.
1191:
1139:: CS1 maint: multiple names: authors list (
1037:
1012:
969:
816:
814:
812:
810:
808:
806:
804:
1205:
1198:
1184:
980:"Optical properties of Rocks and Minerals"
52:. The word traces its origins back to the
1048:
801:
721:
659:
615:
572:
527:
489:
436:
399:
350:
317:
280:
235:
201:
168:
112:
821:Duda, Rudolf & Rejl, Lubos (1990).
597:) is a reflectance effect like that of
348:, which is a form of fossilized resin.
1284:
1077:
865:
554:, where it is caused by impurities of
1179:
884:
775:
773:
410:
957:"Webmineral: Magnetite Mineral Data"
847:"Webmineral: Kaolinite Mineral Data"
609:makes for a green stone and various
523:
123:
13:
1106:
770:
508:minerals have a lustre resembling
447:
328:
246:
14:
1303:
937:"Webmineral: Pyrite Mineral Data"
917:"Webmineral: Galena Mineral Data"
583:
303:. Such minerals possess perfect
1265:
1000:"Webmineral: Amber Mineral Data"
785:Gemological Institute of America
670:
336:minerals have the appearance of
291:
213:
1156:Dictionary of gems and gemology
1147:
1111:(3rd ed.). London: N.A.G.
1100:
1049:Bonewitz, Ronald Louis (2005).
365:
108:
868:Rocks, Crystals & Minerals
859:
706:
500:
179:
1:
763:
626:
455:minerals have the lustre of
82:(derived from the Latin for
7:
1154:Shipley, Robert M. (2007).
732:
536:
158:, with some examples being
10:
1308:
1158:. Read Books. p. 93.
307:, with examples including
1261:
1213:
1107:G., Read, Peter (2008).
558:. It can also occur in
38:see spelling differences
1084:Oxford University Press
781:GIA Gem Reference Guide
752:and is very similar to
78:. Similarly, the term
1207:Mineral identification
870:. Quintet Publishing.
866:Hankin, Rosie (1998).
729:
667:
623:
613:make for a red stone.
580:
533:
497:
444:
407:
362:
325:
288:
243:
210:
176:
120:
1078:Emsley, John (2001).
823:Minerals of the World
725:
715:its best in precious
663:
619:
576:
531:
493:
440:
403:
354:
321:
284:
239:
205:
172:
116:
1057:. pp. 152–153.
512:. Examples include
377:. Examples include
193:Lambertian reflector
1272:Minerals portal
1086:. pp. 451–53.
825:. Arch Cape Press.
266:. Examples include
1055:Dorling Kindersley
730:
668:
624:
581:
534:
498:
445:
411:Submetallic lustre
408:
363:
326:
289:
264:reflective surface
244:
211:
177:
121:
1279:
1278:
1165:978-0-87311-007-5
605:, chrome-bearing
603:aventurine quartz
524:Optical phenomena
195:. An example is
124:Adamantine lustre
1299:
1270:
1269:
1268:
1248:Specific gravity
1200:
1193:
1186:
1177:
1176:
1170:
1169:
1151:
1145:
1144:
1138:
1130:
1104:
1098:
1097:
1075:
1069:
1068:
1046:
1035:
1034:
1032:
1031:
1022:. Archived from
1016:
1010:
1009:
1007:
1006:
996:
990:
989:
987:
986:
976:
967:
966:
964:
963:
953:
947:
946:
944:
943:
933:
927:
926:
924:
923:
913:
907:
906:
904:
903:
894:. Archived from
888:
882:
881:
863:
857:
856:
854:
853:
843:
837:
836:
818:
799:
798:
777:
487:, among others.
137:refractive index
34:American English
1307:
1306:
1302:
1301:
1300:
1298:
1297:
1296:
1282:
1281:
1280:
1275:
1266:
1264:
1257:
1209:
1204:
1174:
1173:
1166:
1152:
1148:
1132:
1131:
1119:
1105:
1101:
1094:
1076:
1072:
1065:
1047:
1038:
1029:
1027:
1018:
1017:
1013:
1004:
1002:
998:
997:
993:
984:
982:
978:
977:
970:
961:
959:
955:
954:
950:
941:
939:
935:
934:
930:
921:
919:
915:
914:
910:
901:
899:
890:
889:
885:
878:
864:
860:
851:
849:
845:
844:
840:
833:
819:
802:
795:
779:
778:
771:
766:
735:
709:
673:
629:
586:
539:
526:
503:
450:
448:Vitreous lustre
413:
368:
331:
329:Resinous lustre
294:
262:will work as a
249:
247:Metallic lustre
216:
182:
126:
111:
26:British English
17:
12:
11:
5:
1305:
1295:
1294:
1277:
1276:
1262:
1259:
1258:
1256:
1255:
1250:
1245:
1240:
1235:
1230:
1228:Crystal system
1225:
1220:
1214:
1211:
1210:
1203:
1202:
1195:
1188:
1180:
1172:
1171:
1164:
1146:
1117:
1099:
1092:
1070:
1063:
1036:
1011:
991:
968:
948:
928:
908:
883:
876:
858:
838:
831:
800:
793:
768:
767:
765:
762:
758:aventurescence
734:
731:
708:
705:
700:Ural Mountains
672:
669:
628:
625:
595:aventurization
590:Aventurescence
585:
584:Aventurescence
582:
538:
535:
525:
522:
502:
499:
449:
446:
412:
409:
367:
364:
330:
327:
293:
290:
260:ideal surfaces
248:
245:
215:
212:
181:
178:
149:cubic zirconia
125:
122:
110:
107:
15:
9:
6:
4:
3:
2:
1304:
1293:
1290:
1289:
1287:
1274:
1273:
1260:
1254:
1251:
1249:
1246:
1244:
1241:
1239:
1236:
1234:
1231:
1229:
1226:
1224:
1223:Crystal habit
1221:
1219:
1216:
1215:
1212:
1208:
1201:
1196:
1194:
1189:
1187:
1182:
1181:
1178:
1167:
1161:
1157:
1150:
1142:
1136:
1128:
1124:
1120:
1118:9780719803611
1114:
1110:
1103:
1095:
1093:0-19-850341-5
1089:
1085:
1081:
1074:
1066:
1064:0-7513-4400-1
1060:
1056:
1052:
1045:
1043:
1041:
1026:on 2011-06-12
1025:
1021:
1015:
1001:
995:
981:
975:
973:
958:
952:
938:
932:
918:
912:
898:on 2011-06-12
897:
893:
887:
879:
877:1-86155-480-X
873:
869:
862:
848:
842:
834:
832:0-517-68030-0
828:
824:
817:
815:
813:
811:
809:
807:
805:
796:
794:0-87311-019-6
790:
786:
782:
776:
774:
769:
761:
759:
755:
754:adularescence
751:
747:
743:
739:
728:
724:
720:
718:
713:
704:
701:
697:
693:
689:
685:
681:
677:
676:Colour change
671:Colour change
666:
662:
658:
656:
652:
648:
644:
640:
637:examples are
635:
634:
622:
618:
614:
612:
608:
604:
600:
596:
592:
591:
579:
575:
571:
569:
565:
561:
557:
553:
549:
545:
544:
530:
521:
519:
515:
511:
507:
496:
492:
488:
486:
482:
478:
474:
470:
466:
462:
458:
454:
443:
439:
435:
433:
429:
425:
421:
417:
406:
402:
398:
396:
392:
388:
384:
380:
376:
372:
361:
357:
353:
349:
347:
343:
339:
335:
324:
320:
316:
314:
310:
306:
302:
298:
292:Pearly lustre
287:
283:
279:
277:
273:
269:
265:
261:
257:
253:
242:
238:
234:
232:
228:
224:
220:
214:Greasy lustre
209:
204:
200:
198:
194:
190:
186:
175:
171:
167:
165:
161:
157:
156:subadamantine
152:
150:
146:
142:
138:
134:
130:
119:
115:
106:
104:
100:
95:
91:
89:
85:
81:
77:
73:
69:
65:
60:
58:
55:
51:
47:
43:
39:
35:
31:
27:
23:
19:
1263:
1237:
1155:
1149:
1108:
1102:
1079:
1073:
1051:Rock and Gem
1050:
1028:. Retrieved
1024:the original
1014:
1003:. Retrieved
994:
983:. Retrieved
960:. Retrieved
951:
940:. Retrieved
931:
920:. Retrieved
911:
900:. Retrieved
896:the original
886:
867:
861:
850:. Retrieved
841:
822:
780:
737:
736:
711:
710:
675:
674:
631:
630:
594:
588:
587:
541:
540:
505:
504:
460:
452:
451:
415:
414:
394:
370:
369:
366:Silky lustre
333:
332:
296:
295:
255:
251:
250:
218:
217:
188:
184:
183:
155:
153:
128:
127:
118:Cut diamonds
109:Common terms
96:
92:
87:
79:
75:
71:
67:
63:
61:
56:
29:
21:
20:
18:
750:labradorite
742:iridescence
727:Labradorite
712:Iridescence
707:Iridescence
696:pleochroism
680:chrysoberyl
665:Alexandrite
639:tiger's eye
621:Tiger's eye
611:iron oxides
501:Waxy lustre
416:Submetallic
389:variety of
358:variety of
342:chewing gum
180:Dull lustre
1292:Mineralogy
1243:Mohs scale
1030:2008-07-14
1005:2008-06-21
985:2008-06-01
962:2008-07-05
942:2008-07-05
922:2008-07-05
902:2008-06-19
852:2008-06-21
764:References
655:tourmaline
647:aquamarine
627:Chatoyancy
578:Aventurine
518:chalcedony
481:tourmaline
428:anthracite
420:sphalerite
405:Sphalerite
387:satin spar
356:Satin spar
227:cordierite
129:Adamantine
103:chatoyancy
1135:cite book
1127:226280870
1109:Gemmology
746:moonstone
651:moonstone
643:cymophane
633:Chatoyant
548:sapphires
309:muscovite
286:Muscovite
276:magnetite
256:splendent
197:kaolinite
174:Kaolinite
141:cerussite
1286:Category
1233:Fracture
1218:Cleavage
787:. 1995.
738:Schiller
733:Schiller
684:sapphire
607:fuchsite
564:diopside
543:Asterism
537:Asterism
532:Sapphire
485:fluorite
453:Vitreous
424:cinnabar
385:and the
379:asbestos
334:Resinous
313:stilbite
305:cleavage
252:Metallic
164:corundum
99:asterism
80:vitreous
68:metallic
599:glitter
465:calcite
432:cuprite
395:fibrous
383:ulexite
231:jadeite
133:diamond
50:mineral
42:crystal
1253:Streak
1238:Lustre
1162:
1125:
1115:
1090:
1061:
874:
829:
791:
692:spinel
688:garnet
568:spinel
560:garnet
556:rutile
552:rubies
469:quartz
461:vitrum
442:Quartz
430:, and
391:gypsum
360:gypsum
301:pearls
297:Pearly
272:pyrite
268:galena
241:Pyrite
219:Greasy
189:earthy
160:garnet
147:, and
145:zircon
88:vitrum
74:, and
72:greasy
64:earthy
30:luster
22:Lustre
477:beryl
473:topaz
457:glass
393:. A
371:Silky
346:amber
338:resin
323:Amber
206:Moss
84:glass
76:silky
54:Latin
48:, or
28:) or
1160:ISBN
1141:link
1123:OCLC
1113:ISBN
1088:ISBN
1059:ISBN
872:ISBN
827:ISBN
789:ISBN
756:and
748:and
717:opal
653:and
641:and
593:(or
566:and
550:and
516:and
514:jade
506:Waxy
495:Jade
483:and
375:silk
311:and
274:and
254:(or
225:and
223:opal
208:opal
187:(or
185:Dull
162:and
46:rock
510:wax
57:lux
1288::
1137:}}
1133:{{
1121:.
1082:.
1053:.
1039:^
971:^
803:^
783:.
772:^
760:.
690:,
686:,
657:.
649:,
570:.
562:,
520:.
479:,
475:,
471:,
467:,
434:.
426:,
422:,
381:,
340:,
315:.
278:.
270:,
229:,
166:.
151:.
143:,
86:,
70:,
66:,
44:,
36:;
1199:e
1192:t
1185:v
1168:.
1143:)
1129:.
1096:.
1067:.
1033:.
1008:.
988:.
965:.
945:.
925:.
905:.
880:.
855:.
835:.
797:.
719:.
32:(
24:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
