Cadmium

a metallic element. It has somewhat the appearance of tin. It crackles when bent. Its chemical properties resemble those of zinc. In combination with sulphur it occurs in most zinc ores. This combination is known as greenockite, and when prepared artificially is of great use to painters who call it cadmium yellow. This sulphide of cadmium gives paint a bright yellow color of great durability. Cadmium may be obtained usually by roasting zinc-blende, as cadmium is more volatile than zinc. Our commercial supply is obtained chiefly from Belgium and Silesia. An iodide of cadmium is used in photography.