Precious Metals

Silver is a brilliant white metal and the best metal in terms of thermal and electrical conductivity. Its chemical symbol, Ag, is derived from its Latin name, argentum, meaning "white and shining." Silver is not nearly as precious, dense, or noble as gold or platinum. The ease with which old silverware tarnishes is an example of its chemical reactivity. Although native silver is found in nature, it most commonly occurs as compounds with other elements, especially sulfur.

Hydrothermal veins constitute the most important source of silver. The Comstock Lode, a silver bonanza 15 mi (24 km) southeast of Reno, Nevada, is a well-known example. Hydrothermal silver veins are formed in the same manner as gold veins, and the two metals commonly occur together. Silver, however, being more reactive than gold, can be leached from surface rocks and carried downward in solution. This process, called super-gene enrichment, can concentrate silver into exceedingly rich deposits at depth.

Mexico has traditionally been the world's leading silver producing country, but the United States, Canada, and Peru each contribute significant amounts. Although silver has historically been considered a precious metal, industrial uses now predominate. Significant quantities are still used in jewelry, silver ware, and coinage; but even larger amounts are consumed by the photographic and electronics industries.