Weilite

Weilite
General
Category Arsenate mineral
Formula
(repeating unit)
CaHAsO4
Strunz classification 8.AD.10
Crystal system Triclinic
Unit cell a = 7.059 Å, b = 6.891 Å
c = 7.201 Å; α = 97.43°
β = 103.55°, γ = 87.75°; Z = 4
Identification
Color White
Crystal habit Powdery, massive
Crystal symmetry Triclinic - pinacoidal
H-M symbol (1)
Space group P1
Fracture Irregular/uneven
Tenacity Brittle
Luster Waxy, greasy, dull
Streak White
Diaphaneity Translucent
Specific gravity 3.48
Optical properties Biaxial (-)
Refractive index nα = 1.644 nγ = 1.688
Birefringence δ = 0.044
2V angle Measured: 81°
References [1][2][3]

Weilite (CaHAsO4) is a rare arsenate mineral. It is a translucent white triclinic mineral with a waxy luster.[1]

It was first described in 1963 for occurrences in Gabe Gottes Mine, Haut-Rhin, Alsace, France; Wittichen, Schenkenzell, Black Forest, Baden-Württemberg, Germany; and the Schneeberg District, Erzgebirge, Saxony, Germany. It is named after French mineralogist René Weil of the University of Strasbourg.[1] It occurs in the oxidized zone of arsenic-bearing hydrothermal veins. It occurs as an alteration product of pharmacolite and haidingerite.[2][3]

References

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