Niedermayrite Locality: Villia Mines, Villia area, Plaka, Lavrion District Mines, Lavrion (Laurion; Laurium) District, Attikí (Attica; Attika) Prefecture, Greece field of view 5 mm. Specimen and photo Leon Hupperichs. — Photo: Leon Hupperichs · CC BY-SA 3.0
Niedermayrite
A rare hydrated copper-cadmium sulfate forming vitreous blue-green prismatic encrustations.
Intro adapted from Wikipedia (CC BY-SA).
Niedermayrite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Cu₄Cd(SO₄)₂(OH)₆·4H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/m).
Key properties: specific gravity 3.29; White streak; Vitreous luster; refractive index 1.63; optically biaxial.
IMA symbol Ndm, IMA status: approved, named in 1997.
Very rare in the oxidation zone of a zinc-rich hydrothermal orebody in brecciated marble, formed as an alteration product of chalcopyrite and greenockite.
It is found associated with Gypsum, malachite, chalcanthite, brochantite, hemimorphite, hydrozincite, aurichalcite, monteponite, otavite, sphalerite, greenockite, hawleyite, pyrite, galena.
The mineral was named to honor Dr. Gerhard Niedermayr (1941–), Curator, Natural History Museum, Vienna, Austria.