31 Facts About Gold


Gold is a chemical element with the symbol Au and atomic number 79.

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Gold often occurs in free elemental form, as nuggets or grains, in rocks, veins, and alluvial deposits.

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Gold is resistant to most acids, though it does dissolve in aqua regia, forming a soluble tetrachloroaurate anion.

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Gold coins ceased to be minted as a circulating currency in the 1930s, and the world gold standard was abandoned for a fiat currency system after the Nixon shock measures of 1971.

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Gold is used in infrared shielding, production of colored glass, gold leafing, and tooth restoration.

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Gold has only one stable isotope, Au, which is its only naturally occurring isotope, so gold is both a mononuclidic and monoisotopic element.

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Gold can be manufactured in a nuclear reactor, but doing so is highly impractical and would cost far more than the value of the gold that is produced.

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Gold chloride is known, an example of a mixed-valence complex.

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Gold is strongly attacked by fluorine at dull-red heat to form gold fluoride.

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Gold has the highest electron affinity of any metal, at 222.

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Gold has a –1 oxidation state in covalent complexes with the group 4 transition metals, such as in titanium tetraauride and the analogous zirconium and hafnium compounds.

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Gold compounds are usually diamagnetic with Au–Au bonds such as [2P2]2Cl2.

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Gold is thought to have been produced in supernova nucleosynthesis, and from the collision of neutron stars, and to have been present in the dust from which the Solar System formed.

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Gold which is reachable by humans has, in one case, been associated with a particular asteroid impact.

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Gold sometimes occurs combined with tellurium as the minerals calaverite, krennerite, nagyagite, petzite and sylvanite, and as the rare bismuthide maldonite and antimonide aurostibite .

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Gold occurs in rare alloys with copper, lead, and mercury: the minerals auricupride, novodneprite and weishanite .

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Gold is mentioned in the Amarna letters numbered 19 and 26 from around the 14th century BC.

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Gold was at a high price in Egypt until they came in that year.

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Gold is further associated with the wisdom of aging and fruition.

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Gold extraction is most economical in large, easily mined deposits.

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Gold extraction is a highly energy-intensive industry, extracting ore from deep mines and grinding the large quantity of ore for further chemical extraction requires nearly 25 kWh of electricity per gram of gold produced.

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Gold has been widely used throughout the world as money, for efficient indirect exchange, and to store wealth in hoards.

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Gold has been used as a symbol for purity, value, royalty, and particularly roles that combine these properties.

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The Australian Gold Kangaroos were first coined in 1986 as the Australian Gold Nugget but changed the reverse design in 1989.

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Gold further rallied hitting new highs in May 2010 after the European Union debt crisis prompted further purchase of gold as a safe asset.

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Gold solder is used for joining the components of gold jewelry by high-temperature hard soldering or brazing.

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Gold solder is usually made in at least three melting-point ranges referred to as Easy, Medium and Hard.

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Gold is highly conductive to electricity, and has been used for electrical wiring in some high-energy applications .

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Gold alloys are used in restorative dentistry, especially in tooth restorations, such as crowns and permanent bridges.

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Gold produces a high output of secondary electrons when irradiated by an electron beam, and these low-energy electrons are the most commonly used signal source used in the scanning electron microscope.

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Gold metal was voted Allergen of the Year in 2001 by the American Contact Dermatitis Society; gold contact allergies affect mostly women.

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