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
Latten is not generally referred to as latten. This calamine brass was generally manufactured as hammered sheet or "battery brass" (hammered by a "battery" of water-powered trip hammers) and cast brass was rare. "Latten" also refers to a type of tin plating on iron (or possibly some other base metal), which is known as "white latten"; and "black latten" refers to "laten-brass", which is brass milled into thin plates or sheets. The term "latten" has also been used, rarely, to refer to lead alloys. In general, metal in thin sheets is said to be latten such as "gold latten"; and "lattens"