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 | |
| Category | Phosphate minerals |
| Formula | CaAl 3(PO 4) 2(OH) 5·H 2O |
| IMA symbol | Cdl |
| Strunz classification | 8.BL.10 |
| Dana classification | 42.07.03.01 |
| Crystal system | Trigonal |
| Unit cell | a = 7.005, c = 16.192, Z = 3; V = 688.09 |
| Identification | |
| Formula mass | 414.02 |
| Colour | grey; yellowish |
| Crystal habit | fibrous, compact or massive |
| Cleavage | perfect 0001 |
| Mohs scale hardness | 4 |
| Luster | vitreous to dull |
| Streak | white |
| Density | 2.84 |
| Refractive index | w = 1.618, e = 1.623 |
| Birefringence | 0.0050 |
| References | |
Crandallite is a calcium aluminium basic phosphate mineral. It has ideal formula CaAl
3(PO
4)
2(OH)
5·H
2O.
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.