Gold has been a valuable and highly sought-after precious metal for coinage, jewelry, and other arts since long before the beginning of recorded history. Gold standards have sometimes been monetary policies, but were widely supplanted by fiat currency starting in the 1930s. The last gold certificate and gold coin currencies were issued in the U.S. in 1932. In Europe, most countries left the gold standard with the start of World War I in 1914 and, with huge war debts, did not return to gold as a medium of exchange.
A total of 171,300 tonnes of gold have been mined in human history, according to GFMS as of 2011. This is roughly equivalent to 5.5 billion troy ounces or, in terms of volume, about 8876 m3, or a cube 20.7 m on a side. The world consumption of new gold produced is about 50% in jewelry, 40% in investments, and 10% in industry.
Besides its widespread monetary and symbolic functions, gold has many practical uses in dentistry, electronics, and other fields. Its high malleability, ductility, resistance to corrosion and most other chemical reactions, and conductivity of electricity has led to many uses, including electric wiring, colored-glass production, and gold leafing.
Most of the Earth’s gold lies at its core, the metal’s high density having made it sink there in the planet’s youth. Virtually all discovered gold is considered to have been deposited later by meteorites that contained the element,with the asteroid that formed Vredefort crater having been implicated in the formation of the largest gold mining region on earth, Witwatersrand basin.