Cabalzarite

Cabalzarite is a rare arsenate mineral with the chemical formula Ca(Mg,Al,Fe³⁺
)
₂[AsO
₄]
₂•2(H
₂O,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.^[2][3]

Cabalzarite
Cabalzarite found in Switzerland
General
Category	Arsenate minerals
Formula	Ca(Mg,Al,Fe3+ ) 2[AsO 4] 2•2(H 2O,OH)
IMA symbol	Clz[1]
Strunz classification	8.CG.15
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	C2/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
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	[2][3][4]

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.^[3]