Arseniosiderite

Arseniosiderite is a rare arsenate mineral formed by the oxidation of other arsenic-containing minerals, such as scorodite or arsenopyrite. It occurs in association with beudantite, carminite, dussertite, pharmacolite, pitticite, adamite and erythrite. The name arseniosiderite reflects two major elements of the mineral, arsenic and iron (Greek sideros means iron).[3]

Arseniosiderite
Arseniosiderite-d06-152a.jpg
Arseniosiderite, size: 6.4×6.2×5.6 mm
General
CategoryArsenate mineral
Formula
(repeating unit)
Ca2Fe3+3(AsO4)3O2·3H2O
Strunz classification8.DH.30 08
Dana classification42.09.02.03
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupA2/a
Unit cella = 17.76, b = 19.53
c = 11.3 [Å], Z = 12
Identification
Formula mass766.50 g/mol
ColorBronze brown; yellow to black
Crystal habitFibrous
Cleavage{100} good
Mohs scale hardness4.5
LusterSubmetallic
StreakOchraceous
DiaphaneityTranslucent to opaque
Specific gravity3.5–3.9, average = 3.7
Optical propertiesBiaxial (-)
Refractive indexnα = 1.815, nβ = 1.898, nγ = 1.898
Birefringenceδ = 0.083
Other characteristicsNon-fluorescent
References[1][2][3]

ReferencesEdit

  1. ^ Arseniosiderite. Mindat.org
  2. ^ Arseniosiderite. Webmineral.com
  3. ^ a b Arseniosiderite. Handbook of mineralogy