Crandallite
Real mineral · rare · CaAl₃(PO₄)₂(OH)₅•(H₂O)
A calcium aluminium phosphate that forms where phosphate rock weathers, usually as dull white crusts and nodules rather than crystals. It is a quiet but widespread part of the phosphate cycle.
Identity
- Formula
- CaAl₃(PO₄)₂(OH)₅•(H₂O)
- Chemical class
- phosphate
Crystallography
- Crystal system
- trigonal
- Habits
- botryoidal, massive, earthy, fibrous
Physical properties
- Mohs hardness
- 4
- Density
- 2.84 g/cm³
- Luster
- dull, vitreous
- Colors
- gray, yellow, yellowish white, light red
- Streak
- white
- Transparency
- translucent, opaque
Geology
- Origins
- sedimentary, hydrothermal
- Host rocks
- phosphorite, pegmatite
- Associated minerals
- Apatite, Wavellite, Quartz
- Geography
- USA, Bolivia, Brazil
Classification
- Rarity
- rare
- Gem quality
- No
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