Moolooite is a rare blue-green mineral with the formula Cu++(C2O4)Ěn(H2O) (n<1) (making it a hydrated copper oxalate). It was discovered by RM Clarke and IR Williams in Bunbury Well, Mooloo Downs station, Murchison, Western Australia in 1986. It has an orthorhombic crystalline structure, and is formed by the interaction of bat guano with weathering copper sulfides.