Zinc oxide

An infusible, insoluble white solid oxide of zinc (ZnO) in the form of a fine white powder used in compounding rubber, as a fungicide, as an absorber of ultraviolet radiation, in pharmaceuticals, in cosmetic preparations, in pigments, as a component in paint to toughen and prevent yellowing, as a semi-conductor, in photocopying processes (related to its photoconductivity), and in ceramic glazes, printing inks, glass colorants, enamels, and lubricants. Zinc oxide is prepared in either of two ways: by the oxidation of pure zinc or by roasting zinc ore. Zinc oxide has been used for various purposes since the Middle Ages, but was rarely used in making pigments until the 19th century.