Arseniosiderite

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Arseniosiderite
Arseniosiderite-d06-152a.jpg
Arseniosiderite, size: 6.4×6.2×5.6 mm
General
Category Arsenate mineral
Formula
(repeating unit)
Ca2Fe3+3(AsO4)3O2·3H2O
Strunz classification 8.DH.30 08
Dana classification 42.09.02.03
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group A2/a
Unit cell a = 17.76, b = 19.53
c = 11.3 [Å], Z = 12
Identification
Formula mass 766.50 g/mol
Color Bronze brown; yellow to black
Crystal habit Fibrous
Cleavage {100} good
Mohs scale hardness 4.5
Luster Submetallic
Streak Ochraceous
Diaphaneity Translucent to opaque
Specific gravity 3.5–3.9, average = 3.7
Optical properties Biaxial (-)
Refractive index nα = 1.815, nβ = 1.898, nγ = 1.898
Birefringence δ = 0.083
Other characteristics Non-fluorescent
References [1][2][3]

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]

References[edit]

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