Collinsite
From Wikipedia, the free encyclopedia
Collinsite is a mineral with chemical formula Ca
2(Mg,Fe2+
)(PO
4)
2•2H
2O. It was discovered in British Columbia, Canada, and formally described in 1927. It was named in honor of William Henry Collins (1878–1937), director of the Geological Survey of Canada. There are three varieties of the mineral: magnesian collinsite, zincian collinsite, and strontian collinsite. The crystal structure consists of polyhedral chains linked by weak hydrogen bonds.
Quick Facts General, Category ...
Collinsite | |
---|---|
General | |
Category | Phosphate mineral |
Formula (repeating unit) | Ca 2(Mg,Fe2+ )(PO 4) 2•2H 2O |
IMA symbol | Coll[1] |
Strunz classification | 8.CG.05 |
Dana classification | 40.2.2.3 |
Crystal system | Triclinic |
Crystal class | Pinacoidal (1) (same H-M symbol) |
Space group | P1 |
Unit cell | a = 5.734(1) Å b = 6.780(1) Å c = 5.441(1) Å α = 97.29°, β = 108.56°, γ = 107.28°; Z = 1[2] |
Identification | |
Cleavage | Fair on {001} and {010} |
Tenacity | Brittle[2] |
Mohs scale hardness | 3 to 3.5 |
Luster | Subvitreous, silky if fibrous[2] |
Streak | White[2] |
Diaphaneity | Translucent |
Specific gravity | 2.99 |
Optical properties | Biaxial (+) |
Refractive index | nα = 1.632 nβ = 1.642 nγ = 1.657 |
Birefringence | δ = 0.025 |
2V angle | 80° (measured) |
Dispersion | r < v strong |
Ultraviolet fluorescence | Non-fluorescent[3] |
Solubility | Readily soluble in acids |
References | [4] |
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