Wikipedia
Lepersonnite-(Gd)
Lepersonnite-(Gd) is a very rare rare earth and uranium mineral with the formula Ca(Gd,Dy)(UO)(SiO)(CO)(OH)•48HO. It associates with bijvoetite-(Y) in Shinkolobwe deposit in Republic of Congo, famous for rare uranium minerals. Lepersonnite-(Gd) is unique in being the only confirmed mineral with essential gadolinium.