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Crandallite

Crandallite
Variscite and crandallite. Locality: Little Green Monster Variscite Mine, Clay Canyon, Fairfield, Oquirrh Mountains, Utah County, Utah, US. Size: 7.8 × 7.3 × 0.4 cm.
General
CategoryPhosphate minerals
Formula
(repeating unit)
CaAl
3
(PO
4
)
2
(OH)
5
·H
2
O
IMA symbolCdl[1]
Strunz classification8.BL.10
Dana classification42.07.03.01
Crystal systemTrigonal
Unit cella = 7.005, c = 16.192, Z = 3; V = 688.09
Identification
Formula mass414.02
Colourgrey; yellowish
Crystal habitfibrous, compact or massive
Cleavageperfect 0001
Mohs scale hardness4
Lustervitreous to dull
Streakwhite
Density2.84
Refractive indexw = 1.618, e = 1.623
Birefringence0.0050
References[2]

Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula CaAl
3
(PO
4
)
2
(OH)
5
·H
2
O
. Crandallite was named after Milan L. Crandall, Jr, who worked for Knight Syndicate. This mineral is found in laterite and in alteration products of phosphate rich pegmatites.

References

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ "Crandallite Mineral Data". webmineral.com.