Silver is the metallic element with the atomic number 47. Its symbol is Ag, from the Latin argentum, from a PIE root reconstructed as *h₂erǵ-, "grey" or "shining". A soft, white, lustrous transition metal, it possesses the highest electrical conductivity, thermal conductivity, and reflectivity of any metal. The metal occurs naturally in its pure, free form (native silver), as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Most silver is produced as a byproduct of copper, gold, lead, and zinc refining.
Silver has long been valued as a precious metal. More abundant than gold, silver metal has functioned in many premodern monetary systems as coinable specie, sometimes even alongside gold. Its purity is typically measured on a per-mille basis; a 94%-pure alloy is described as "0.940 fine". In addition, silver has numerous applications beyond currency, such as in solar panels, water filtration, jewelry and ornaments, high-value tableware and utensils (hence the term silverware), and also as an investment in the forms of coins and bullion. Silver is used industrially in electrical contacts and conductors, in specialized mirrors, window coatings and in catalysis of chemical reactions. Its compounds are used in photographic film and X-rays. Dilute silver nitrate solutions and other silver compounds are used as disinfectants and microbiocides (oligodynamic effect), added to bandages and wound-dressings, catheters and other medical instruments.
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