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
Crystal system Orthorhombic Dipyramidal H-M Symbol (2/m 2/m 2/m)
Identification
Color White, pink
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 Barrer, a New Zealand-born chemist.[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

Wikimedia Commons has media related to Barrerite.
This article is issued from Wikipedia - version of the Monday, February 29, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.