Forms of copper ore. Selection of four types of copper ore, clockwise from lower left: native copper, bornite, azurite, and a mixture of malachite and azurite. Copper is one of only a few metals to occur in nature in elemental (native) form. It is more often found combined with other elements, such as with oxygen in the form of copper oxide. Bornite, also called peacock ore, is a mixture of copper, iron and sulphur. Azurite is a mixture of copper and carbonate and hydroxide ions. Azurite can gradually change into malachite, which contains the same elements, but with a different structure.