Niedermayrite is a rare hydrated cadmium mineral with formula: Cu )6·4H2O 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. 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 The environment is in brecciated marble. The cadmium.