Wiktionary
margaritasite
n. (context mineralogy English) A yellow monoclinic caesium-bearing mineral in the carnotite group.
Wikipedia
Margaritasite
Margaritasite is a yellow, caesium-bearing mineral in the carnotite group. Its chemical formula is ( Cs, K, HO)( U O) VOยท HO and its crystal system is monoclinic.