29:
536:
OH group and there are three oxygens that neighbor them. The silicon tetrahedra are arranged so that they share an edge with calcium(1), and silicon(2) shares edges with the calcium(2) and calcium(3) polyhedral. The silicon tetrahedra are held together by the OH group and hydrogen bonding occurs between the hydrogen in the OH and the silicon tetrahedra. Hydrogen bonding is caused because the positive ion, hydrogen, is attracted to negatively charge ions which, in this case, are the silicon tetrahedra.
535:
faces. The sheets are bonded together by hydrogen bonds and are all connected by Ca-Si-O bonds (Malik & Jeffery, 1976). Each calcium atom is in 6-fold octahedral coordination with the oxygen, and the silicon is in 4-fold tetrahedral coordination around the oxygen. Around each silicon there is one
483:
are all minerals that form in layers within spurrite veins. It appears that afwillite, as well as calcite, forms from precipitated fluids. Jennite is actually an alteration of afwillite, but both formed from calcium silicates through hydration. Laboratory studies determined that afwillite forms at a
508:
parallel to its (101) and poor cleavage parallel to its (100) faces. It is biaxial and its 2V angle, the measurement from one optical axis to the other optical axis, is 50 – 56 degrees. When viewed under crossed polarizers in a
513:, it displays first-order orange colors, giving a maximum birefringence of 0.0167 (determined by using the Michel–Levy chart). Afwillite is optically positive. Additionally, it has a
28:
848:
531:
that consist of calcium and silicon polyhedral connected to each other by sharing corners and edges. This causes continuous sheets to form parallel to its
853:
797:
863:
488:
of limestone. Contact metamorphism is caused by the interaction of rock with heat and/or fluids from a nearby crystallizing silicate
97:
776:
Malik, K. M. A & Jeffery J. W. (1976) A re-investigation of the structure of afwillite. Acta
Crystallographica, B32, 475.
386:
214:
735:
Kusachi, I, Henmi, C. And Henmi K. (1989) Afwillite and jennite from Fuka, Okayama
Prefecture. Japan. Miner J. 14, 279-292.
247:
858:
34:
500:
Afwillite has a complex monoclinic structure, and the silicon tetrahedra in the crystal structure are held together by
484:
temperature below 200 °C (392 °F), usually around 100 °C. Afwillite and spurrite are formed through
823:
463:
and it belongs to the nesosilicate sub-class. It is monoclinic, its space group is P2 and its point group is 2.
592:
545:
510:
449:
87:
838:
204:
194:
656:
557:
485:
390:
794:
430:
317:
237:
227:
528:
674:
505:
184:
434:
410:
843:
833:
359:
149:
476:
664:
585:
514:
275:
257:
57:
828:
801:
549:
721:
660:
573:
501:
107:
817:
678:
297:
174:
119:
50:
532:
521:
705:
471:
It is suggested that afwillite forms in fractured veins of the mineral spurrite.
760:
Klein, C. and Dutrow, K. (2007) Manual of
Mineral Science. 23rd Edition, 63, 596
624:
614:
426:
398:
137:
785:
609:
452:
and was named for
Alpheus Fuller Williams (1874–1953), a past official of the
422:
406:
382:
128:
112:
745:
16:
Nesosilicate alteration mineral also sometimes found in hydrated cement paste
418:
402:
394:
356:
599:
553:
460:
453:
448:
It was first described in 1925 for an occurrence in the
Dutoitspan Mine,
414:
307:
669:
644:
604:
561:
517:
480:
472:
442:
438:
362:
353:
691:
389:
hardness is between 3 and 4. It occurs as an alteration mineral in
489:
795:
http://www.minersoc.org/pages/Archive-MM/Volume_29/29-216-838.pdf
620:
Other calcium aluminium silicate hydrate (C-A-S-H) minerals:
179:
Prismatic (striated), tabular, radial fibrous, massive
772:
770:
768:
766:
731:
729:
381:
O. It occurs as glassy, colorless to white prismatic
756:
754:
340:
332:
316:
306:
296:
274:
266:
256:
246:
236:
226:
213:
203:
193:
183:
173:
165:
160:
148:
136:
118:
106:
96:
86:
56:
46:
41:
21:
520:habit. Under a microscope afwillite looks like
156:c = 13.236(1) ; β = 134.9°; Z = 4
744:Barthemy, D. (2000) Afwillite Mineral Data, (
8:
552:sets to form hardened cement paste (HCP) in
524:, which is in the same family as afwillite.
746:http://webmineral.com/data/Afwillite.shtml
27:
668:
459:Afwillite is typically found in veins of
701:
699:
849:Geology of Riverside County, California
806:The thermal decomposition of afwillite,
635:
18:
717:
715:
713:
7:
645:"IMA–CNMNC approved mineral symbols"
564:of tri- and di- calcium silicates (C
14:
33:Afwillite from Crestmore Quarry,
397:. It occurs in association with
1:
854:Crestmore Heights, California
154:a = 16.278(1), b = 5.6321(4)
35:Riverside County, California
189:Perfect along , good along
880:
252:Transparent to translucent
864:Minerals in space group 9
808:The Mineralogical Society
692:Mindat with location data
546:calcium silicate hydrates
527:Afwillite is composed of
26:
593:calcium silicate hydrate
544:Afwillite is one of the
496:Structure and properties
548:(C-S-H) that form when
511:petrographic microscope
450:Kimberley, South Africa
722:Handbook of Mineralogy
649:Mineralogical Magazine
556:. The cement gets its
540:Occurrence in concrete
333:Other characteristics
98:Strunz classification
804:Moody, K. M., 1952,
486:contact metamorphism
391:contact metamorphism
312:Measured: 50° to 56°
859:Monoclinic minerals
670:10.1180/mgm.2021.43
661:2021MinM...85..291W
643:Warr, L.N. (2021).
595:(C-S-H) minerals:
800:2016-05-27 at the
572:S) present in the
267:Optical properties
504:. It has perfect
456:diamond company.
347:
346:
132:
871:
824:Calcium minerals
809:
792:
786:
783:
777:
774:
761:
758:
749:
742:
736:
733:
724:
719:
708:
703:
694:
689:
683:
682:
672:
640:
586:List of minerals
276:Refractive index
258:Specific gravity
219:
169:Colorless, white
126:
63:
62:(repeating unit)
31:
19:
879:
878:
874:
873:
872:
870:
869:
868:
814:
813:
812:
802:Wayback Machine
793:
789:
784:
780:
775:
764:
759:
752:
743:
739:
734:
727:
720:
711:
706:Webmineral data
704:
697:
690:
686:
642:
641:
637:
633:
582:
571:
567:
550:Portland cement
542:
498:
469:
380:
376:
372:
368:
365:with formula Ca
291:
287:
283:
217:
155:
125:
81:
77:
73:
69:
61:
60:
37:
17:
12:
11:
5:
877:
875:
867:
866:
861:
856:
851:
846:
841:
836:
831:
826:
816:
815:
811:
810:
787:
778:
762:
750:
737:
725:
709:
695:
684:
655:(3): 291–320.
634:
632:
629:
628:
627:
618:
617:
612:
607:
602:
589:
588:
581:
578:
569:
565:
541:
538:
502:hydrogen bonds
497:
494:
468:
465:
385:crystals. Its
378:
374:
370:
366:
345:
344:
342:
338:
337:
334:
330:
329:
320:
314:
313:
310:
304:
303:
300:
294:
293:
289:
285:
281:
278:
272:
271:
268:
264:
263:
260:
254:
253:
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244:
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234:
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220:
211:
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207:
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180:
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170:
167:
163:
162:
161:Identification
158:
157:
152:
146:
145:
140:
134:
133:
122:
116:
115:
110:
108:Crystal system
104:
103:
100:
94:
93:
90:
84:
83:
79:
75:
71:
67:
64:
54:
53:
48:
44:
43:
39:
38:
32:
24:
23:
15:
13:
10:
9:
6:
4:
3:
2:
876:
865:
862:
860:
857:
855:
852:
850:
847:
845:
842:
840:
839:Nesosilicates
837:
835:
832:
830:
827:
825:
822:
821:
819:
807:
803:
799:
796:
791:
788:
782:
779:
773:
771:
769:
767:
763:
757:
755:
751:
747:
741:
738:
732:
730:
726:
723:
718:
716:
714:
710:
707:
702:
700:
696:
693:
688:
685:
680:
676:
671:
666:
662:
658:
654:
650:
646:
639:
636:
630:
626:
623:
622:
621:
616:
613:
611:
608:
606:
603:
601:
598:
597:
596:
594:
587:
584:
583:
579:
577:
575:
563:
559:
555:
551:
547:
539:
537:
534:
530:
529:double chains
525:
523:
519:
516:
512:
507:
503:
495:
493:
491:
487:
482:
478:
475:, afwillite,
474:
466:
464:
462:
457:
455:
451:
446:
444:
440:
436:
432:
431:hillebrandite
428:
424:
420:
416:
412:
408:
404:
400:
396:
392:
388:
384:
364:
361:
358:
355:
351:
343:
339:
336:Piezoelectric
335:
331:
328:
324:
321:
319:
315:
311:
309:
305:
301:
299:
298:Birefringence
295:
279:
277:
273:
269:
265:
261:
259:
255:
251:
249:
245:
241:
239:
235:
231:
229:
225:
221:
216:
212:
208:
206:
202:
198:
196:
192:
188:
186:
182:
178:
176:
175:Crystal habit
172:
168:
164:
159:
153:
151:
147:
144:
141:
139:
135:
130:
123:
121:
120:Crystal class
117:
114:
111:
109:
105:
101:
99:
95:
91:
89:
85:
65:
59:
55:
52:
51:Nesosilicates
49:
45:
40:
36:
30:
25:
20:
805:
790:
781:
740:
687:
652:
648:
638:
619:
590:
543:
533:Miller index
526:
522:wollastonite
499:
470:
458:
447:
360:nesosilicate
349:
348:
326:
322:
142:
124:Domatic (m)
625:Tacharanite
615:Tobermorite
427:portlandite
399:apophyllite
270:Biaxial (+)
248:Diaphaneity
138:Space group
818:Categories
631:References
610:Thaumasite
423:ettringite
407:thaumasite
387:Mohs scale
383:monoclinic
341:References
318:Dispersion
302:δ = 0.0167
215:Mohs scale
199:Conchoidal
129:H-M symbol
113:Monoclinic
88:IMA symbol
679:235729616
562:hydration
560:from the
515:prismatic
467:Formation
435:foshagite
419:gehlenite
411:merwinite
403:natrolite
395:limestone
357:hydroxide
350:Afwillite
288:= 1.620 n
284:= 1.617 n
150:Unit cell
22:Afwillite
844:Hydrates
834:Concrete
798:Archived
600:Gyrolite
580:See also
558:strength
554:concrete
506:cleavage
461:spurrite
454:De Beers
415:spurrite
308:2V angle
232:Vitreous
218:hardness
205:Tenacity
195:Fracture
185:Cleavage
47:Category
657:Bibcode
605:Jennite
574:clinker
568:S and C
518:crystal
481:calcite
477:oyelite
473:Jennite
443:calcite
439:brucite
363:mineral
354:calcium
292:= 1.634
209:Brittle
102:9.AG.75
58:Formula
42:General
829:Cement
677:
591:Other
238:Streak
228:Luster
127:(same
675:S2CID
490:magma
352:is a
325:<
262:2.630
242:White
166:Color
479:and
441:and
369:(SiO
70:(SiO
665:doi
393:of
377:·2H
373:OH)
222:3–4
92:Afw
78:·2H
74:OH)
820::
765:^
753:^
728:^
712:^
698:^
673:.
663:.
653:85
651:.
647:.
576:.
492:.
445:.
437:,
433:,
429:,
425:,
421:,
417:,
413:,
409:,
405:,
401:,
143:Cc
66:Ca
748:)
681:.
667::
659::
570:2
566:3
379:2
375:2
371:3
367:3
327:v
323:r
290:γ
286:β
282:α
280:n
131:)
82:O
80:2
76:2
72:3
68:3
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