Niedermayrite

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Niedermayrite
Niedermayrite-320849.jpg
Niedermayrite from Ophir Hill area, Ophir District, Oquirrh Mountains, Tooele County, Utah, USA
General
Category Sulfate mineral
Formula
(repeating unit)
Cu4Cd(SO4)2(OH)6·4H2O
Strunz classification 7.DD.30
Crystal system Monoclinic
Crystal class Prismatic (2/m)
(same H-M symbol)
Space group P21/m
Unit cell a = 5.543(1), b = 21.995(4)
c = 6.079(1) [Å]; β = 92.04(3)°; Z = 2
Identification
Color Bluish green
Crystal habit Platy euhedral crystals and as green crusts
Cleavage Perfect on {010}
Tenacity Brittle
Luster Vitreous
Streak White
Diaphaneity Transparent
Specific gravity 3.292
Optical properties Biaxial (-)
Refractive index nα = 1.599 - 1.619 nβ = 1.642 nγ = 1.661
Birefringence δ = 0.062
2V angle Measured: 84°
References [1][2]

Niedermayrite is a rare hydrated copper cadmium sulfate hydroxide mineral with formula: Cu4Cd(SO4)2(OH)6·4H2O. It crystallizes in the monoclinic system and occurs as encrustations and well formed vitreous blue-green prismatic crystals. It has a specific gravity of 3.36.

Niedermayrite was named for Gerhard Niedermayr (born 1941), an Austrian mineralogist. It was first described in 1998 from a mine in the Lavrion District, Attica, Greece. It is also reported from the Ophir District, Tooele County, Utah.[1] The environment is in brecciated marble. The cadmium dominant analogue of campigliaite.

References[edit]