Silver, often referred to as a "precious metal," has been used for thousands of years in an impressive array of applications, including as coins and as a financial standard, instrument and tool material, chemical catalyst, electrical conductor, and medicinal ingredient and adjunct. It occurs throughout the earth's crust at an average concentration by weight of 80 ppb and in sea water at 0.1 ppb. Life-threatening toxicity of silver is uncommon, but chronic exposure may lead to permanent disability.
Silver has considerable strength and malleability, as well as excellent thermal and electrical conductivity, due to its weak interaction with oxygen (second only to gold). These properties are responsible for its widespread use throughout the health, science, and engineering industries, where it remains a key component of batteries, mechanical bearings, catalysts, coins, electroplating, mirrors, coatings, photography, medical bactericidal agents, and water purification.
This prevalence of silver notwithstanding, silver poisoning is rare and is often the result of occupational exposure or self-administration of silver-containing products for unproven medicinal purposes. Since the mid-20th century, the use of silver for medicinal purposes has infrequently resulted in iatrogenic overuse and subsequent argyria, which is a permanent bluish-gray discoloration of skin that is the primary manifestation of chronic silver overexposure.5
Although the symbol of silver, Ag, is derived from the Latin and Greek words for silver—argentum and argyros—the word we use in English is derived from Slavic and Germanic Silubr and Sirebro and Old English Seolfor. Even the alchemy symbol of silver (a crescent moon) and dalton symbol (a coinlike circumscribed letter S) etch the impression of silver as a valued and precious element.
In Asia Minor and on islands in the Aegean Sea, dumps of slag (scum formed by molten metal surface oxidation) demonstrate that silver may have been separated from lead as early as 4000 B.C. The use of silver as a precious metal with trade value appears to have begun around 600 B.C., when weighed pieces of silver were exchanged for goods. Silver coinage debuted circa 550 B.C. in the Mediterranean and was adopted by various empires, dynasties, and nation-states thereafter. Today, only Mexico uses silver in circulating coinage; the United States incorporates silver purely in commemorative and proof coins.
The Phoenicians and early Greeks knew to store water, wine, and vinegar in silver-lined vessels during long sea voyages, just as later American pioneers added silver coins to water barrels and jugs of milk to keep them fresh.37 The phrase "born with a silver spoon in his mouth" referred originally to health rather than wealth because silver pacifiers and baby spoons were used to help ward off childhood illnesses.
A traded commodity on the world's markets, silver had been used as an abstract financial standard for various economies throughout modern banking history until the late 19th century.
Beyond the economic role of ...