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
General
CategorySulfate mineral
Formula
(repeating unit)
Cu4Cd(SO4)2(OH)6·4H2O
IMA symbolNdm[1]
Strunz classification7.DD.30
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupP21/m
Unit cella = 5.543(1), b = 21.995(4)
c = 6.079(1) [Å]; β = 92.04(3)°; Z = 2
Identification
ColorBluish green
Crystal habitPlaty euhedral crystals and as green crusts
CleavagePerfect on {010}
TenacityBrittle
LusterVitreous
StreakWhite
DiaphaneityTransparent
Specific gravity3.292
Optical propertiesBiaxial (-)
Refractive indexnα = 1.599 - 1.619 nβ = 1.642 nγ = 1.661
Birefringenceδ = 0.062
2V angleMeasured: 84°
References[2][3]

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.[2] The environment is in brecciated marble. The cadmium dominant analogue of campigliaite.

References

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  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 Niedermayrite on Mindat.org
  3. ^ Niedermayrite data on Webmineral