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
Rolled Alloys Rolled Alloys Rolled Alloys is a private company headquartered in Temperance, Michigan, in the United States. Rolled Alloys is a supplier in the metal industry for both heat resistant and corrosion resistant alloys. The company has between 201-500 employees throughout the world. Rolled Alloys' key markets are Aerospace, Chemical Processing, Medical, Oil and Gas, Power Generation, and Thermal Processing. Rolled Alloys Canada also deals in the Pulp / Paper and Mining markets. Rolled Alloys has expanded through acquisitions of other companies: Harvey Titanium, Weaver Steel, Super Alloys, SMS London, Clasma Trade, and RA® Materials (formerly Weir Materials and Foundry). Rolled