Cabalzarite

Cabalzarite
General
Category Arsenate minerals
Formula
(repeating unit)
Ca(Mg,Al,Fe3+)2[AsO4]2·2(H2O,OH)
Strunz classification 08.CG.15
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: C 2/m
Unit cell a = 8.925 Å, b = 6.143 Å, c = 7.352 Å, β = 115.25°; Z = 2
Identification
Color Light brown, brownish pink, orange brown
Crystal habit Aggregates and clusters, granular
Crystal system Monoclinic
Fracture Irregular
Mohs scale hardness 5
Luster Vitreous
Streak White
Diaphaneity transparent
Specific gravity 3.89
Optical properties Biaxial
Refractive index nα = 1.700 nγ = 1.760
Birefringence δ = 0.060
References [1][2][3]

Cabalzarite is a rare arsenate mineral with formula: (Ca(Mg,Al,Fe3+)2[AsO4]2·2(H2O,OH). It is a member of the tsumcorite group. It crystallizes in the monoclinic system and typically occurs as clusters of crystals or granular aggregates.[1][2]

It was first described for samples from an abandoned manganese mine in Falotta, Graubünden, Switzerland and named for Swiss amateur mineralogist Walter Cabalzar. It was approved as a new mineral by the IMA in 1997. It has also been reported from the Aghbar mine in Ouarzazate Province, Morocco.[2]

References

  1. 1.0 1.1 Cabalzarite mineral data from Webmineral
  2. 2.0 2.1 2.2 Cabalzarite mineral information on Mindat.org
  3. Brugger J., Meisser N., Schenk K., Berlepsch P., Bonin M., Armbruster T., Nyfeler D. and Schmidt S. 2000: Description and crystal structure of cabalzarite Ca(Mg,Fe,Al)2(AsO4)2(H2O,OH)2, a new mineral from the tsumcorite group. American Mineralogist, 85(9), 1307-1314;