WURTZITE (named in honor of Charles Adolphe Wurtz). A mineral zinc sulphide crystallized in the hexagonal system. It has a resinous lustre, and is brownish-black in color. It occurs in crystals or in massive fibrous varieties. It is found in Portugal, Bolivia, Peru, and in the United States, with sphalerite and quartz, at Butte, Mont. This mineral has been made artificially by fusing equal parts of zinc sulphate with calcium fluoride and barium sulphide.