Light green needles of ulrichite from the type locality Lake Boga, Australia (width of the crystal aggregate: 1 mm) — Photo: Klaproth · CC BY-SA 4.0
Ulrichite
An apple-green calcium-copper uranyl phosphate that fluoresces yellow — radioactive.
Intro adapted from Wikipedia (CC BY-SA).
Ulrichite is an IMA-recognized mineral species in the phosphate class, with the chemical formula CaCu(UO₂)(PO₄)₂·4H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m).
Key properties: Mohs hardness 3.5; specific gravity 3.71; White streak; Vitreous luster; optically biaxial.
IMA symbol Ulr, IMA status: approved, named in 1988.
Found as a secondary mineral in miarolitic cavities in pegmatoidal granite.
It is found associated with Turquoise-chalcosiderite, cyrilovite, torbernite, libethenite, sampleite, saléeite, fluorapatite.
The mineral was named to honor George Henry Frederick Ulrich (1830–1900), for his contributions to the mineralogy of Victoria, Australia.