Silver

Silver is a chemical element with the symbol Ag (from the Latin argentum, derived from the Proto-Indo-European associated with 'shiny' or 'white') and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal is found in the Earth's crust in the pure, free elemental form ('native silver'), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite.

Formation & Geology

Silver is found in native form very rarely as nuggets, but more usually combined with sulfur, arsenic, antimony, or chlorine and in various ores, such as argentite (Ag2S) and chlorargyrite ('horn silver', AgCl). The principal sources of silver are the ores of copper, copper-nickel, lead, and lead-zinc obtained from Peru, Mexico, China, Australia, Chile, Poland and Serbia. Peru and Mexico have been mining silver since 1546.

Physical Characteristics

Silver is extremely ductile, malleable, and soft. It has a brilliant white metallic luster that can take a high polish. Its electrical conductivity is the highest of all metals, even higher than copper, but it is not widely used for electrical purposes because of its high cost. Pure silver has the highest thermal conductivity of any metal.

Historical Significance

Silver has been known since ancient times. It is mentioned in the Book of Genesis. Slag dumps in Asia Minor and on islands in the Aegean Sea indicate that silver was being separated from lead as early as the 4th millennium BC. The stability of the Roman currency relied to a high degree on the supply of silver bullion.