What is Zeunerite?
Zeunerite is a vivid green hydrated copper uranyl arsenate from oxidised uranium deposits, prized by specialists for its colour, tabular crystals and strong geochemical identity.
Mineralogy and structure
Reference formula: Cu(UO2)2(AsO4)2·10H2O. Zeunerite is tetragonal and strongly hydrated. Its green colour is attractive, but the combination of uranium and arsenic makes it a scientific specimen requiring controlled display; the COD model is a labelled representative. Zeunerite is classified with phosphates and has tetragonal crystal symmetry. Typical hardness is 2–2.5 on the Mohs scale and specific gravity is approximately 3.5–3.7.
Colour, lustre and habit
Typical colours include green, yellow-green, emerald green. The usual tabular, crusty, rosette habit and vitreous, pearly lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Zeunerite forms in or is associated with secondary oxidation zones of uranium-copper arsenic deposits and mine fractures. Important documented localities include Germany, Czechia, France, Portugal, the United States and other uranium districts.
Emerald colour with serious collector credentials
Zeunerite is a high-impact cabinet mineral: saturated green plates can be spectacular, while documented uranium-mine provenance makes the specimen meaningful to both collectors and mineralogists.
Collecting and care
Radioactive and arsenic-bearing: keep sealed, dry and away from dust, heat and casual handling. Follow local radiation-safety rules and never use a specimen for jewellery or wellness products.
