Chabazite

Chabazite

Orange chabazite rhombs with white heulandite from Nova Scotia
General
Category Tectosilicate
Formula
(repeating unit)		 (Ca,K2,Na2)2[Al2Si4O12]2·12H2O
Strunz classification 9.GD.10
Crystal system Trigonal
Crystal class Hexagonal scalenohedral 3m
H-M symbol: (3 2/m)
Space group R3m
Identification
Color Colorless, white, yellow, pink, red
Cleavage distinct/good on {1011}
Fracture irregular/uneven
Mohs scale hardness 4-5
Luster vitreous
Streak white
Diaphaneity transparent, translucent
Specific gravity 2.05 - 2.2
References [1]

Chabazite (English pronunciation: /ˈkæbəzaɪt/)[2] is a tectosilicate mineral of the zeolite group,[3] closely related to gmelinite, with formula (Ca,Na2,K2,Mg)Al2Si4O12·6H2O. Recognized varieties include Chabazite-Ca, Chabazite-K, Chabazite-Na, and Chabazite-Sr, depending on the prominence of the indicated cation.

Chabazite crystallizes in the triclinic crystal system with typically rhombohedral shaped crystals[2] that are pseudo-cubic. The crystals are typically twinned, and both contact twinning and penetration twinning may be observed. They may be colorless, white, orange, brown, pink, green, or yellow. The hardness ranges from 3 to 5 and the specific gravity from 2.0 to 2.2. The luster is vitreous.

It was named chabasie in 1792 by Bosc d'Antic and later changed to the current spelling.

Chabazite occurs most commonly in voids and amygdules in basaltic rocks.

Chabazite is found in India, Iceland, the Faroe Islands, the Giants Causeway in Northern Ireland, Bohemia, Italy, Germany, along the Bay of Fundy in Nova Scotia, Oregon, Arizona, and New Jersey.

Synthetic chabazite

Many different materials isostructural with the chabazite mineral have been synthesized in laboratories. SSZ-13 is a CHA type zeolite with an Si/Al ratio of 14. This is a composition not found in nature.

References

  1. ↑ Mineralienatlas
  2. 1 2 The New Oxford Dictionary of English (1998) ISBN 0-19-861263-X - p.300 "chabazite /'kabəzʌɪt/ noun "A colourless, pink or yellow zeolite mineral, typically occurring as rhombohedral crystals.".
  3. ↑  Chisholm, Hugh, ed. (1911). "Chabazite". Encyclopædia Britannica. 5 (11th ed.). Cambridge University Press. p. 785.
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