Malachite

A native carbonate of copper, forming a beautiful and permanent green pigment, used for oils and water-colours. Incrusted upon other materials it is used for articles of ornament. Blue malachite is pure carbonate of copper; green malachite is green carbonate of copper; emerald or royal malachite is dioptase of copper, a still rarer green and the best of all, which is a mixture of copper and silica; false or pseudo -malachite is phosphate of copper, soft and silky, and of a rich velvet green marred by black spots or lines, and not so rich as the three kinds of true malachite.