in the center are two pale-yellow tufts of Oursinite, also on the specimen are orange Billietite and other yellow secondary uranium minerals,from Shinkolobwe Mine, Katanga, D.R.Congo FOV: 5mm — Photo: Weirdmeister · CC BY-SA 4.0
Oursinite
Oursinite is an IMA-recognized mineral species in the silicate class, with the chemical formula Co(UO₂)₂(SiO₃OH)₂·6H₂O.
It crystallizes in the orthorhombic crystal system (space group Cmca).
Key properties: specific gravity 3.674; optically biaxial.
IMA symbol Osn, IMA status: approved, named in 1982.
Found as a secondary mineral in brecciated dolostone containing uraninite.
It is found associated with Soddyite, kasolite, schoepite, sklodowskite, torbernite, lepersonnite, bijvoetite, curite.
The name comes from the French oursin, meaning sea urchin, in allusion to the mineral's appearance.