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Barrerite

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Barrerite
Barrerite from Kuiu Island, Alaska, USA.
General
CategoryZeolite
Formula
(repeating unit)
(Na,K,Ca)2Al2Si7O18·6(H2O)
IMA symbolBre[1]
Strunz classification9.GE.15
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupAmma
Identification
ColorWhite, pink
CleavagePerfect
Mohs scale hardness3 - 4
LusterVitreous-glassy
StreakWhite
DiaphaneityTransparent to translucent
Specific gravity2.13
Optical propertiesBiaxial (-)
Refractive indexnα = 1.479 nβ = 1.485 nγ = 1.489
References[2][3][4]

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.[4]

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.[4] It has also been reported from Rocky Pass, Kuiu Island, Alaska, and a few other localities.

References

[edit]
  1. ^ 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.
  2. ^ "Mineralienatlas - Fossilienatlas". www.mineralienatlas.de. Retrieved 2023-06-29.
  3. ^ "Barrerite Mineral Data". webmineral.com. Retrieved 2023-06-29.
  4. ^ a b c "Barrerite".