Claudetite

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claudetite
Claudetite-I-layer-3D-balls.png
General
Category Oxide minerals
Formula
(repeating unit)
As2 O3
Strunz classification 04.CB.45
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: P 21/n
Unit cell a = 5.33 Å, b = 12.98 Å, c = 4.54 Å; β = 94.27°; Z=4
Identification
Color Colorless to white
Crystal habit Thin tabular crystals, fibrous crusts
Crystal system Monoclinic
Twinning Contact or penetration on {100}
Cleavage Perfect on {010} micaceous
Fracture Splintery
Tenacity Flexible
Mohs scale hardness 2.15
Luster Vitreous, pearly on cleavage surfaces
Diaphaneity Transparent
Specific gravity 4.14 - 4.15
Optical properties Biaxial (-)
Refractive index nα = 1.870 nβ = 1.920 nγ = 2.010
Birefringence δ = 0.140
2V angle 58° (measured)
References [1][2][3]

Claudetite is an arsenic oxide mineral with chemical formula As2O3. Claudetite is formed as an oxidation product of arsenic sulfides and is colorless or white. It can be associated with arsenolite (the cubic form of As2O3) as well as realgar (As4S4), orpiment (As2S3) and native sulfur.[1]

It was first described in 1868 for an occurrence in the San Domingo mines, Algarve, Portugal. It was first described by and named for the French chemist Frederick Claudet.[2]

References[edit]