Tungstite
Tungstite | |
---|---|
Bright yellow tungstite on ferberite | |
General | |
Category | Mineral |
Formula (repeating unit) | WO3·H2O |
Strunz classification | 04.FJ.10 |
Identification | |
Formula mass | 249.86 g/mol |
Color | Yellow, yellowish green/orange |
Crystal habit | Earthy, pulverulent |
Crystal system | Orthorhombic dipyramidal |
Cleavage | Perfect along [001], imperfect along [110] |
Mohs scale hardness | 2.5 |
Luster | Resinous, pearly |
Streak | Yellow |
Diaphaneity | Transparent |
Specific gravity | 5.517 |
Optical properties | Biaxial (-) |
Refractive index | nα = 2.090, nβ = 2.240, nγ = 2.260 |
Birefringence | δ = 0.170 |
Dispersion | r < v (strong) |
Tungstite is a hydrous tungsten oxide mineral with formula: WO3·H2O. It is a secondary mineral formed by the weathering of other tungsten containing minerals. It crystallizes in the orthorhombic system in translucent yellow to yellow green masses. It is clay-like with Mohs hardness of 2.5 and a specific gravity of 5.5.
It was first described in 1868 for an occurrence near Trumbull, Connecticut at the Hubbard Tungsten Mine at Long Hill.
References
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