1) Uranium mineral 
Billietite is an uncommon mineral of Uranium that contains Barium. It has the chemical formula: Ba(UO2)6O4(OH)6•8H2O. It usually occurs as clear yellow orthorhombic crystals. Billietite is named after Valere Louis Billiet (1903–1944), Belgian crystallographer at the University of Ghent, Ghent, Belgium. ...