 An example is the lead mineral anglesite PbSO4.Copper may be precipitated as malachite Cu2(CO3)(OH)2 or azurite Cu3(CO3)2(OH)2.Malachite, azurite, cuprite Cu2O, pyromorphite Pb5(PO4)3Cl and smithsonite ZnCO3 are stable in oxidising conditions and they are characteristic of the oxidation zone.