Demesmaekerite
Demesmaekerite is an uranium mineral with the chemical formula: Pb2Cu5(UO2)2(SeO3)6(OH)6•2H2O.
It is named after the Belgian mineralogist, who worked at the Musonoi Mine, Gaston Demesmaeker (born 1911). It is a secondary mineral which contains lead, copper and (the rarer in minerals) selenium, it is a bottle green to brown/yellow colour, its crystal habit changes from one form to another form depending on where it is found. It has a Mohs hardness of about 2-3.