Claudetite

Claudetite
General
CategoryOxide minerals
Formula
(repeating unit)
As2 O3
IMA symbolCtd[1]
Strunz classification4.CB.45
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/n
Unit cella = 5.33 Å, b = 12.98 Å,
c = 4.54 Å; β = 94.27°; Z = 4
Identification
ColorColorless to white
Crystal habitThin tabular crystals, fibrous crusts
TwinningContact or penetration on {100}
CleavagePerfect on {010} micaceous
FractureSplintery
TenacityFlexible
Mohs scale hardness2.15
LusterVitreous, pearly on cleavage surfaces
DiaphaneityTransparent
Specific gravity4.14–4.15
Optical propertiesBiaxial (−)
Refractive indexnα = 1.870 nβ = 1.920 nγ = 2.010
Birefringenceδ = 0.140
2V angle58° (measured)
References[2][3][4]

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.[2]

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.[3]

  1. ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
  2. ^ a b Handbook of Mineralogy
  3. ^ a b Claudetite data on Webmineral
  4. ^ Claudetite on Mindat