Tungstite
Appearance
Tungstite | |
---|---|
General | |
Category | Mineral |
Formula (repeating unit) | WO3·H2O |
IMA symbol | Tgs[1] |
Strunz classification | 4.FJ.10 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
Space group | Pmnb |
Identification | |
Formula mass | 249.86 g/mol |
Color | Yellow, yellowish green/orange |
Crystal habit | Earthy, pulverulent |
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
[edit]- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
Wikimedia Commons has media related to Tungstite.