Inyoite
Inyoite, named after Inyo County, California, where it was discovered in 1914, is a colourless monoclinic mineral. It turns white on dehydration. Its chemical formula is Ca(H4B3O7)(OH)·4H2O or CaB3O3(OH)5·4H2O.[2]
Inyoite | |
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General | |
Category | Nesoborates |
Formula (repeating unit) | CaB3O3(OH)5·4H2O |
Strunz classification | 6.CA.35 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | P21/a |
Unit cell | a = 10.63, b = 12.06 c = 8.4 [Å]; β = 114.03°; Z = 4 |
Identification | |
Colour | Colourless, white on dehydration. |
Crystal habit | Commonly as prismatic to tabular crystals; also in cockscomb aggregates of pseudorhombohedral crystals; coarsely spherulitic or granular |
Cleavage | Good on {001}, distinct on {010} |
Fracture | Irregular/uneven |
Tenacity | Brittle |
Mohs scale hardness | 2 |
Lustre | Vitreous |
Specific gravity | 1.875 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.495 nβ = 1.505 - 1.512 nγ = 1.520 |
Birefringence | Maximum δ = 0.025 |
Dispersion | Weak |
References | [1][2] |
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