Margaritasite
Margaritasite is a yellow, caesium-bearing mineral in the carnotite group. Its chemical formula is (Cs, K, H3O)2(UO2)2V2O8·H2O and its crystal system is monoclinic.
Name and discovery
It was first described in 1982 from the Margaritas uranium deposit, in the Peña Blanca district of the municipality of Aldama, in the Mexican state of Chihuahua.