Speculum metal metal mixtures usually contain two parts copper to one part tin along with a small amount of arsenic, although there are other mixtures containing silver, lead, or zinc. The knowledge of making very hard white high luster metal out of bronze-type high-tin alloys may date back more than 2000 years in China although it could also be an invention of western civilizations. Such metals were used in sculpture and to make more effective mirrors than the more common yellow easily tarnishing bronze mirrors. In that era mirrors of speculum metal, or any precious metal, were rare and only owned by
Bronze sculpture showing that they are made of bronze, not a cheaper alloy such as spelter or pewter. Bronze sculpture Bronze is the most popular metal for cast metal sculptures; a cast bronze sculpture is often called simply a "bronze". It can be used for statues, singly or in groups, reliefs, and small statuettes and figurines, as well as bronze elements to be fitted to other objects such as furniture. It is often gilded to give gilt-bronze or ormolu. Common bronze alloys have the unusual and desirable property of expanding slightly just before they set, thus filling the finest details of a