Moolooite is a rare blue-green mineral with the formula Cu⁺⁺(C₂O₄)·n(H₂O) (n<1) (making it a hydrated copper oxalate). It was discovered by Richard M Clarke and Ian R 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 bird guano with weathering copper sulfides.