Zeunerite, Cu(UO2)2(AsO4)2 - 10-16H2O (hydrated copper uranyl aresenate), is a rare uranyl arsenate that is similar to the more well known uranyl phosphate mineral, torbernite. — Photo: Nessa Eull · CC0
Zeunerite
A green copper uranyl arsenate of the autunite group — fluorescent and radioactive.
Intro adapted from Wikipedia (CC BY-SA).
Zeunerite is an IMA-recognized mineral species in the arsenate class, with the chemical formula Cu(UO₂)₂(AsO₄)₂·12H₂O.
It crystallizes in the tetragonal crystal system (space group I4/mmm). It is a member of the Autunite structural group.
Key properties: Mohs hardness 2.5; specific gravity 3.47; Vitreous luster; refractive index 1.598; optically uniaxial.
IMA symbol Zeu, grandfathered status — known before the IMA’s founding, named in 1872.
Occurs as an uncommon secondary mineral in the oxidized zone of arsenic-bearing hydrothermal uranium deposits.
It is found associated with Olivenite, mansfieldite, scorodite, azurite, malachite.
The mineral was named to honor Gustav Anton Zeuner (1828-1907), Director, School of Mines, Freiberg, Germany.