Cuprosklodowskite , Uranophane - alpha Locality: Musonoi Mine, Kolwezi , Western area, Katanga Copper Crescent, Katanga (Shaba) , Democratic Republic of Congo (Zaïre) ( Locality at mindat.org ) This remarkable specimen clearly shows embedded crystals of green Cuprosklodowskite altering to Uranophane , yellow and altered by the time it reaches the protected shallow cavity in the center of the piece. Most unusual! 5.9 x 3.1 x 2.3 cm — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Cuprosklodowskite
A grass-green secondary uranium silicate forming needle-like crystals where earlier uranium minerals have altered.
Intro adapted from Wikipedia (CC BY-SA).
Cuprosklodowskite is an IMA-recognized mineral species in the silicate class, with the chemical formula Cu(UO₂)₂(SiO₃OH)₂·6H₂O.
It crystallizes in the triclinic crystal system (space group P-1).
Key properties: Mohs hardness 4; specific gravity 3.85; Dull to silky in aggregates luster; refractive index 1.662; optically biaxial.
IMA symbol Cskl, grandfathered status — known before the IMA’s founding, named in 1933.
Forms secondarily through alteration of earlier uranium minerals, both in situ and after transport of solutions.
It is found associated with Becquerelite, brochantite, uranophane, kasolite, vandenbrandeite, liebigite, uranophane-beta, compreignacite.
A name supplied by Buttgenbach while introducing Vaes' paper, in the mistaken belief that it was the copper analog of sklodowskite.