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 07.DD.30
Crystal symmetry Monoclinic prismatic
H-M symbol: (2/m)
Space group: P 21/m
Unit cell a = 5.543(1) Å, b = 21.995(4) Å, c = 6.079(1) Å; β = 92.04(3)°; Z=2
Identification
Color Bluish green
Crystal habit Platy euhedral crystals and as green crusts
Crystal system Monoclinic
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]