1278:
734:
363:
293:
672:
449:
540:
412:
181:
628:
585:
214:
125:
502:
330:
248:
725:
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
104:
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
647:
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
713:
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.
709:. 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
612:. 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
429:
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
474:.) 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
48:
1208:
1151:
232:
minerals resemble fat or grease. A greasy lustre often occurs in minerals containing a great abundance of microscopic inclusions, with examples including
1174:
210:. A distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, and having even less lustre.
1127:
1102:
1073:
902:
886:
841:
803:
1030:
795:
105:
species). The terms are frequently combined to describe intermediate types of lustre (for example, a "vitreous greasy" lustre).
1194:
1253:
310:
minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of
755:
originating from below the surface of a stone that occurs when light is reflected between layers of minerals. It is seen in
116:(the display of luminous bands, which appear to move as the specimen is rotated). A list of such phenomena is given below.
1201:
202:) minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, approximating a
1094:
1217:
203:
1243:
756:
661:
553:
274:
109:
1302:
1263:
384:
minerals have a parallel arrangement of extremely fine fibres, giving them a lustre reminiscent of
1228:
1145:
1065:
315:
150:(of 1.9 or more). Minerals with a true adamantine lustre are uncommon, with examples including
1170:
1133:
1123:
1098:
1069:
882:
837:
799:
1258:
693:
gemstones. Other gems also occur in colour-change varieties, including (but not limited to)
147:
44:
1282:
362:
36:
906:
1238:
1034:
768:
733:
710:
649:
631:
600:
165:
Minerals with a lesser (but still relatively high) degree of lustre are referred to as
159:
56:
1296:
1233:
764:
270:
671:
292:
448:
990:
857:
760:
752:
737:
706:
690:
675:
653:
352:
128:
705:. Alexandrite displays a colour change dependent upon light, along with strong
903:"Emporia State University: GO 340 Gemstones & Gemology: Visual Properties"
665:
643:
621:
613:
588:
528:
491:
438:
430:
415:
397:
366:
237:
113:
1137:
967:
319:
296:
286:
207:
184:
151:
947:
927:
539:
70:, meaning "light", and generally implies radiance, gloss, or brilliance.
27:
Manner in which light interacts with a crystal, rock, or mineral's surface
1186:
1010:
694:
617:
574:
558:
495:
434:
389:
323:
174:
411:
180:
17:
627:
609:
584:
475:
442:
393:
241:
213:
143:
124:
60:
52:
501:
702:
698:
578:
570:
566:
479:
452:
401:
370:
282:
278:
251:
244:. Many minerals with a greasy lustre also feel greasy to the touch.
170:
155:
142:
minerals possess a superlative lustre, which is most notably seen in
329:
247:
101:) refers to a glassy lustre. A list of these terms is given below.
557:
is the display of a star-shaped luminous area. It is seen in some
732:
670:
657:
626:
583:
538:
500:
487:
483:
467:
447:
410:
361:
356:
348:
333:
328:
311:
291:
246:
212:
179:
123:
94:
64:
1031:"Emporia State University: GO 340 Gemstones & Gemology: Jade"
727:
562:
524:
505:
385:
233:
218:
146:. Such minerals are transparent or translucent, and have a high
1190:
520:
656:, but the effect may also occur in other minerals such as
108:
Some minerals exhibit unusual optical phenomena, such as
269:) minerals have the lustre of polished metal, and with
1091:
Nature's
Building Blocks: An A-Z Guide to the Elements
73:
A range of terms are used to describe lustre, such as
355:
or (smooth-surfaced) plastic. A principal example is
689:
is most commonly found in alexandrite, a variety of
51:) is the way light interacts with the surface of a
470:. (The term is derived from the Latin for glass,
112:(the display of a star-shaped luminous area) or
1055:
1053:
1051:
985:
983:
751:(German, literally "shimmer"), is the metallic
408:lustre is similar, but has a coarser texture.
1202:
8:
1150:: CS1 maint: multiple names: authors list (
827:
825:
823:
821:
819:
817:
815:
1209:
1195:
1187:
991:"Optical properties of Rocks and Minerals"
63:. The word traces its origins back to the
832:Duda, Rudolf & Rejl, Lubos (1990).
780:
608:) is a reflectance effect like that of
359:, which is a form of fossilized resin.
1143:
565:, where it is caused by impurities of
786:
784:
7:
968:"Webmineral: Magnetite Mineral Data"
858:"Webmineral: Kaolinite Mineral Data"
620:makes for a green stone and various
519:minerals have a lustre resembling
25:
948:"Webmineral: Pyrite Mineral Data"
928:"Webmineral: Galena Mineral Data"
314:. Such minerals possess perfect
1276:
1011:"Webmineral: Amber Mineral Data"
796:Gemological Institute of America
347:minerals have the appearance of
1167:Dictionary of gems and gemology
1122:(3rd ed.). London: N.A.G.
1060:Bonewitz, Ronald Louis (2005).
879:Rocks, Crystals & Minerals
1:
466:minerals have the lustre of
93:(derived from the Latin for
1165:Shipley, Robert M. (2007).
169:, with some examples being
1319:
1169:. Read Books. p. 93.
318:, with examples including
1272:
1224:
1118:G., Read, Peter (2008).
569:. It can also occur in
49:see spelling differences
1095:Oxford University Press
792:GIA Gem Reference Guide
763:and is very similar to
89:. Similarly, the term
1218:Mineral identification
881:. Quintet Publishing.
877:Hankin, Rosie (1998).
740:
678:
634:
624:make for a red stone.
591:
544:
508:
455:
418:
373:
336:
299:
254:
221:
187:
131:
1089:Emsley, John (2001).
834:Minerals of the World
736:
726:its best in precious
674:
630:
587:
542:
504:
451:
414:
365:
332:
295:
250:
216:
183:
127:
1068:. pp. 152–153.
523:. Examples include
388:. Examples include
204:Lambertian reflector
1283:Minerals portal
1097:. pp. 451–53.
836:. Arch Cape Press.
277:. Examples include
1066:Dorling Kindersley
741:
679:
635:
592:
545:
509:
456:
422:Submetallic lustre
419:
374:
337:
300:
275:reflective surface
255:
222:
188:
132:
1290:
1289:
1176:978-0-87311-007-5
616:, chrome-bearing
614:aventurine quartz
535:Optical phenomena
206:. An example is
135:Adamantine lustre
16:(Redirected from
1310:
1281:
1280:
1279:
1259:Specific gravity
1211:
1204:
1197:
1188:
1181:
1180:
1162:
1156:
1155:
1149:
1141:
1115:
1109:
1108:
1086:
1080:
1079:
1057:
1046:
1045:
1043:
1042:
1033:. Archived from
1027:
1021:
1020:
1018:
1017:
1007:
1001:
1000:
998:
997:
987:
978:
977:
975:
974:
964:
958:
957:
955:
954:
944:
938:
937:
935:
934:
924:
918:
917:
915:
914:
905:. Archived from
899:
893:
892:
874:
868:
867:
865:
864:
854:
848:
847:
829:
810:
809:
788:
498:, among others.
148:refractive index
45:American English
21:
1318:
1317:
1313:
1312:
1311:
1309:
1308:
1307:
1293:
1292:
1291:
1286:
1277:
1275:
1268:
1220:
1215:
1185:
1184:
1177:
1164:
1163:
1159:
1142:
1130:
1117:
1116:
1112:
1105:
1088:
1087:
1083:
1076:
1059:
1058:
1049:
1040:
1038:
1029:
1028:
1024:
1015:
1013:
1009:
1008:
1004:
995:
993:
989:
988:
981:
972:
970:
966:
965:
961:
952:
950:
946:
945:
941:
932:
930:
926:
925:
921:
912:
910:
901:
900:
896:
889:
876:
875:
871:
862:
860:
856:
855:
851:
844:
831:
830:
813:
806:
790:
789:
782:
777:
746:
720:
684:
640:
597:
550:
537:
514:
461:
459:Vitreous lustre
424:
379:
342:
340:Resinous lustre
305:
273:will work as a
260:
258:Metallic lustre
227:
193:
137:
122:
37:British English
28:
23:
22:
15:
12:
11:
5:
1316:
1314:
1306:
1305:
1295:
1294:
1288:
1287:
1273:
1270:
1269:
1267:
1266:
1261:
1256:
1251:
1246:
1241:
1239:Crystal system
1236:
1231:
1225:
1222:
1221:
1216:
1214:
1213:
1206:
1199:
1191:
1183:
1182:
1175:
1157:
1128:
1110:
1103:
1081:
1074:
1047:
1022:
1002:
979:
959:
939:
919:
894:
887:
869:
849:
842:
811:
804:
779:
778:
776:
773:
769:aventurescence
745:
742:
719:
716:
711:Ural Mountains
683:
680:
639:
636:
606:aventurization
601:Aventurescence
596:
595:Aventurescence
593:
549:
546:
536:
533:
513:
510:
460:
457:
423:
420:
378:
375:
341:
338:
304:
301:
271:ideal surfaces
259:
256:
226:
223:
192:
189:
160:cubic zirconia
136:
133:
121:
118:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1315:
1304:
1301:
1300:
1298:
1285:
1284:
1271:
1265:
1262:
1260:
1257:
1255:
1252:
1250:
1247:
1245:
1242:
1240:
1237:
1235:
1234:Crystal habit
1232:
1230:
1227:
1226:
1223:
1219:
1212:
1207:
1205:
1200:
1198:
1193:
1192:
1189:
1178:
1172:
1168:
1161:
1158:
1153:
1147:
1139:
1135:
1131:
1129:9780719803611
1125:
1121:
1114:
1111:
1106:
1104:0-19-850341-5
1100:
1096:
1092:
1085:
1082:
1077:
1075:0-7513-4400-1
1071:
1067:
1063:
1056:
1054:
1052:
1048:
1037:on 2011-06-12
1036:
1032:
1026:
1023:
1012:
1006:
1003:
992:
986:
984:
980:
969:
963:
960:
949:
943:
940:
929:
923:
920:
909:on 2011-06-12
908:
904:
898:
895:
890:
888:1-86155-480-X
884:
880:
873:
870:
859:
853:
850:
845:
843:0-517-68030-0
839:
835:
828:
826:
824:
822:
820:
818:
816:
812:
807:
805:0-87311-019-6
801:
797:
793:
787:
785:
781:
774:
772:
770:
766:
765:adularescence
762:
758:
754:
750:
743:
739:
735:
731:
729:
724:
717:
715:
712:
708:
704:
700:
696:
692:
688:
687:Colour change
682:Colour change
681:
677:
673:
669:
667:
663:
659:
655:
651:
648:examples are
646:
645:
637:
633:
629:
625:
623:
619:
615:
611:
607:
603:
602:
594:
590:
586:
582:
580:
576:
572:
568:
564:
560:
556:
555:
547:
541:
534:
532:
530:
526:
522:
518:
511:
507:
503:
499:
497:
493:
489:
485:
481:
477:
473:
469:
465:
458:
454:
450:
446:
444:
440:
436:
432:
428:
421:
417:
413:
409:
407:
403:
399:
395:
391:
387:
383:
376:
372:
368:
364:
360:
358:
354:
350:
346:
339:
335:
331:
327:
325:
321:
317:
313:
309:
303:Pearly lustre
302:
298:
294:
290:
288:
284:
280:
276:
272:
268:
264:
257:
253:
249:
245:
243:
239:
235:
231:
225:Greasy lustre
224:
220:
215:
211:
209:
205:
201:
197:
190:
186:
182:
178:
176:
172:
168:
167:subadamantine
163:
161:
157:
153:
149:
145:
141:
134:
130:
126:
119:
117:
115:
111:
106:
102:
100:
96:
92:
88:
84:
80:
76:
71:
69:
66:
62:
58:
54:
50:
46:
42:
38:
34:
30:
19:
1274:
1248:
1166:
1160:
1119:
1113:
1090:
1084:
1062:Rock and Gem
1061:
1039:. Retrieved
1035:the original
1025:
1014:. Retrieved
1005:
994:. Retrieved
971:. Retrieved
962:
951:. Retrieved
942:
931:. Retrieved
922:
911:. Retrieved
907:the original
897:
878:
872:
861:. Retrieved
852:
833:
791:
748:
747:
722:
721:
686:
685:
642:
641:
605:
599:
598:
552:
551:
516:
515:
471:
463:
462:
426:
425:
405:
381:
380:
377:Silky lustre
344:
343:
307:
306:
266:
262:
261:
229:
228:
199:
195:
194:
166:
164:
139:
138:
129:Cut diamonds
120:Common terms
107:
103:
98:
90:
86:
82:
78:
74:
72:
67:
40:
32:
31:
29:
761:labradorite
753:iridescence
738:Labradorite
723:Iridescence
718:Iridescence
707:pleochroism
691:chrysoberyl
676:Alexandrite
650:tiger's eye
632:Tiger's eye
622:iron oxides
512:Waxy lustre
427:Submetallic
400:variety of
369:variety of
353:chewing gum
191:Dull lustre
1303:Mineralogy
1254:Mohs scale
1041:2008-07-14
1016:2008-06-21
996:2008-06-01
973:2008-07-05
953:2008-07-05
933:2008-07-05
913:2008-06-19
863:2008-06-21
775:References
666:tourmaline
658:aquamarine
638:Chatoyancy
589:Aventurine
529:chalcedony
492:tourmaline
439:anthracite
431:sphalerite
416:Sphalerite
398:satin spar
367:Satin spar
238:cordierite
140:Adamantine
114:chatoyancy
1146:cite book
1138:226280870
1120:Gemmology
757:moonstone
662:moonstone
654:cymophane
644:Chatoyant
559:sapphires
320:muscovite
297:Muscovite
287:magnetite
267:splendent
208:kaolinite
185:Kaolinite
152:cerussite
1297:Category
1244:Fracture
1229:Cleavage
798:. 1995.
749:Schiller
744:Schiller
695:sapphire
618:fuchsite
575:diopside
554:Asterism
548:Asterism
543:Sapphire
496:fluorite
464:Vitreous
435:cinnabar
396:and the
390:asbestos
345:Resinous
324:stilbite
316:cleavage
263:Metallic
175:corundum
110:asterism
91:vitreous
79:metallic
18:Lustrous
610:glitter
476:calcite
443:cuprite
406:fibrous
394:ulexite
242:jadeite
144:diamond
61:mineral
53:crystal
1264:Streak
1249:Lustre
1173:
1136:
1126:
1101:
1072:
885:
840:
802:
703:spinel
699:garnet
579:spinel
571:garnet
567:rutile
563:rubies
480:quartz
472:vitrum
453:Quartz
441:, and
402:gypsum
371:gypsum
312:pearls
308:Pearly
283:pyrite
279:galena
252:Pyrite
230:Greasy
200:earthy
171:garnet
158:, and
156:zircon
99:vitrum
85:, and
83:greasy
75:earthy
41:luster
33:Lustre
488:beryl
484:topaz
468:glass
404:. A
382:Silky
357:amber
349:resin
334:Amber
217:Moss
95:glass
87:silky
65:Latin
59:, or
39:) or
1171:ISBN
1152:link
1134:OCLC
1124:ISBN
1099:ISBN
1070:ISBN
883:ISBN
838:ISBN
800:ISBN
767:and
759:and
728:opal
664:and
652:and
604:(or
577:and
561:and
527:and
525:jade
517:Waxy
506:Jade
494:and
386:silk
322:and
285:and
265:(or
236:and
234:opal
219:opal
198:(or
196:Dull
173:and
57:rock
521:wax
68:lux
1299::
1148:}}
1144:{{
1132:.
1093:.
1064:.
1050:^
982:^
814:^
794:.
783:^
771:.
701:,
697:,
668:.
660:,
581:.
573:,
531:.
490:,
486:,
482:,
478:,
445:.
437:,
433:,
392:,
351:,
326:.
289:.
281:,
240:,
177:.
162:.
154:,
97:,
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77:,
55:,
47:;
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1196:v
1179:.
1154:)
1140:.
1107:.
1078:.
1044:.
1019:.
999:.
976:.
956:.
936:.
916:.
891:.
866:.
846:.
808:.
730:.
43:(
35:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
