Barrerite
Barrerite | |
---|---|
Barrerite from Kuiu Island, Alaska, USA. | |
General | |
Category | Zeolite |
Formula (repeating unit) | (Na,K,Ca)2Al2Si7O18·6(H2O) |
Strunz classification | 09.GE.15 |
Identification | |
Color | White, pink |
Crystal system | Orthorhombic Dipyramidal H-M Symbol (2/m 2/m 2/m) |
Cleavage | Perfect |
Mohs scale hardness | 3 - 4 |
Luster | Vitreous-glassy |
Streak | White |
Diaphaneity | Transparent to translucent |
Specific gravity | 2.13 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.479 nβ = 1.485 nγ = 1.489 |
References | [1][2] |
Barrerite is a tectosilicate mineral and a member of the zeolite family. It is one of the rarer zeolites. It was named for Richard Maling Barrer (1910–1996), a British teacher born in New Zealand.[2]
Barrerite crystal are white to pinkish, with a vitreous-glassy luster. The crystal system is orthorhombic and is flat and tabular in appearance. It has a Mohs hardness of 3 to 4 and its cleavage is perfect. Barrerite has a white streak and a density of 2.13.
It was first described in 1974 for an occurrence in Sardinia at Sant' Efisio Tower on Cape Pula in Cagliari Province.[2] It has also been reported from Rocky Pass, Kuiu Island, Alaska, and a few other localities.
References
- ↑ http://webmineral.com/data/Barrerite.shtml Webmineral data
- ↑ 2.0 2.1 2.2 http://www.mindat.org/min-536.html Mindat.org
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