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
Ampco Metal Ampco Metal AMPCO METAL is a diversified speciality alloy engineering company working primarily in copper based alloys, non-sparking safety tools and speciality welding products. The Switzerland based company is a manufacturer of engineered alloys of different compositions and properties, intended for specific uses in the aerospace, automotive, energy conservation, manufacturing and other industries. It also produces non-sparking safety tools for the oil industry, as well as the firefighting and fire prevention sectors. Additionally, AMPCO METAL provides engineering, machining and welding advice to the industry, in matters involving its speciality copper, aluminium-bronze and other alloys. AMPCO METAL currently employs approximately 250