A metal of a bluish-white color, having a crystalline structure. It is brittle at ordinary temperatures, but when heated it becomes malleable, and does not lose this quality when cooled. If raised to a red heat in a closed vessel, it will boil and pass off in vapor, and when heated in the air it burns with a bright flame. When exposed to damp air, a thin coating of rust is formed, which prevents the further oxidation of the metal. Combined with copper, it forms the alloy brass, and it also forms an ingredient in German silver. In the metallic state it is used for roofing, for rain-pipes, for gutters, and as a coating for sheet-iron and iron wire. Iron covered with zinc in this way is known as galvanized iron. Zinc is also used in some electric batteries; and as an oxide it is employed as a pigment.