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Gold is a chemical element; it has chemical symbol Au (from Latin aurum) and atomic number 79. In its pure form, it is a brightness, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal, a group 11 element, and one of the . It is one of the least reactive chemical elements, being the second lowest in the reactivity series, with only platinum ranked as less reactive. Gold is solid under standard conditions.
Gold often occurs in (native state), as gold nugget or grains, in rocks, veins, and . It occurs in a solid solution series with the native element silver (as in electrum), naturally with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium ().
Gold is resistant to most acids, though it does dissolve in aqua regia (a mixture of nitric acid and hydrochloric acid), forming a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid alone, which dissolves silver and , a property long used to refine gold and confirm the presence of gold in metallic substances, giving rise to the term "acid test". Gold dissolves in alkaline solutions of cyanide, which are used in gold cyanidation and electroplating. Gold also dissolves in mercury, forming amalgam alloys, and as the gold acts simply as a solute, this is not a chemical reaction.
A relatively rare element when compared to silver (though thirty times more common than platinum), gold is a precious metal that has been used for gold coin, jewelry, and other works of art throughout recorded history. In the past, a gold standard was often implemented as a monetary policy. 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.
In 2023, the world's largest gold producer was China, followed by Russia and Australia. , a total of around 201,296 of gold exist above ground. If all of this gold were put together into a cube shape, each of its sides would measure . The world's consumption of new gold produced is about 50% in jewelry, 40% in , and 10% in Manufacturing. Gold's high malleability, ductility, resistance to corrosion and most other chemical reactions, as well as conductivity of electricity have led to its continued use in corrosion-resistant electrical connectors in all types of computerized devices (its chief industrial use). Gold is also used in infrared shielding, the production of colored glass, , and tooth restoration. Certain gold salts are still used as anti-inflammatory agents in medicine.
The symbol Au is from the Latin aurum]] .Notre Dame University Latin Dictionary Retrieved 7 June 2012 The Proto-Indo-European ancestor of aurum was *h₂é-h₂us-o-, meaning . This word is derived from the same root (Proto-Indo-European *h₂u̯es- ) as , the ancestor of the Latin word aurora . This etymological relationship is presumably behind the frequent claim in scientific publications that aurum meant .Christie, A and Brathwaite, R. (Last updated 2 November 2011) Mineral Commodity Report 14 — Gold, Institute of geological and Nuclear sciences Ltd – Retrieved 7 June 2012
Gold has a density of 19.3 g/cm3, almost identical to that of tungsten at 19.25 g/cm3; as such, tungsten has been used in the counterfeiting of , such as by plating a tungsten bar with gold.Willie, Jim (18 November 2009) " Zinc Dimes, Tungsten Gold & Lost Respect ". Kitco By comparison, the density of lead is 11.34 g/cm3, and that of the densest element, osmium, is .
Common colored gold alloys include the distinctive eighteen-karat rose gold created by the addition of copper. Alloys containing palladium or nickel are also important in commercial jewelry as these produce white gold alloys. Fourteen-karat gold-copper alloy is nearly identical in color to certain bronze alloys, and both may be used to produce police and other . Fourteen- and eighteen-karat gold alloys with silver alone appear greenish-yellow and are referred to as green gold. Blue gold can be made by alloying with iron, and purple gold can be made by alloying with aluminium. Less commonly, addition of manganese, indium, and other elements can produce more unusual colors of gold for various applications.
Colloidal gold, used by electron-microscopists, is red if the particles are small; larger particles of colloidal gold are blue.
At least 32 have also been characterized, ranging in atomic mass from 170 to 200. Within that range, only , , , , and do not have isomers. Gold's most stable isomer is with a half-life of 2.27 days. Gold's least stable isomer is with a half-life of only 7 ns. has three decay paths: β+ decay, isomeric transition, and alpha decay. No other isomer or isotope of gold has three decay paths.
Au(III) (referred to as auric) is a common oxidation state, and is illustrated by gold(III) chloride, . The gold atom centers in Au(III) complexes, like other d8 compounds, are typically square planar, with that have both covalent and character. Gold(I,III) chloride is also known, an example of a mixed-valence complex.
Gold does not react with oxygen at any temperature and, up to 100 °C, is resistant to attack from ozone: (1995). 9780871705181, ASM International. ISBN 9780871705181
Some free react to form the corresponding gold halides. (2025). 9780123526519, Academic Press. ISBN 9780123526519 Gold is strongly attacked by fluorine at dull-red heat to form gold(III) fluoride . Powdered gold reacts with chlorine at 180 °C to form gold(III) chloride . Gold reacts with bromine at 140 °C to form a combination of gold(III) bromide and gold(I) bromide AuBr, but reacts very slowly with iodine to form gold(I) iodide AuI:
Gold does not react with sulfur directly, but gold(III) sulfide can be made by passing hydrogen sulfide through a dilute solution of gold(III) chloride or chlorauric acid.
Unlike sulfur, phosphorus reacts directly with gold at elevated temperatures to produce gold phosphide (Au2P3).
Gold readily dissolves in mercury at room temperature to form an amalgam, and forms with many other metals at higher temperatures. These alloys can be produced to modify the hardness and other metallurgical properties, to control melting point or to create exotic colors.
Gold is unaffected by most acids. It does not react with hydrofluoric, hydrochloric, hydrobromic acid, hydriodic acid, sulfuric acid, or nitric acid. It does react with selenic acid, and is dissolved by aqua regia, a 1:3 mixture of nitric acid and hydrochloric acid. Nitric acid oxidizes the metal to +3 ions, but only in minute amounts, typically undetectable in the pure acid because of the chemical equilibrium of the reaction. However, the ions are removed from the equilibrium by hydrochloric acid, forming ions, or chloroauric acid, thereby enabling further oxidation:
Gold is similarly unaffected by most bases. It does not react with aqueous solution, solid, or molten sodium hydroxide or potassium hydroxide. It does however, react with sodium cyanide or potassium cyanide under alkaline conditions when oxygen is present to form soluble complexes.
Common of gold include +1 (gold(I) or aurous compounds) and +3 (gold(III) or auric compounds). Gold ions in solution are readily reduced and precipitated as metal by adding any other metal as the reducing agent. The added metal is oxidation and dissolves, allowing the gold to be displaced from solution and be recovered as a solid precipitate.
The −1 oxidation state occurs in aurides, compounds containing the anion. Caesium auride (CsAu), for example, crystallizes in the caesium chloride motif; rubidium, potassium, and tetramethylammonium aurides are also known. (2025). 9780123526519, Academic Press. ISBN 9780123526519 Gold has the highest electron affinity of any metal, at 222.8 kJ/mol, making a stable species, analogous to the .
Gold also 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. These chemicals are expected to form gold-bridged dimers in a manner similar to titanium(IV) hydride.
Gold(II) compounds are usually diamagnetic with Au–Au bonds such as [. The evaporation of a solution of in concentrated produces red crystals of gold(II) sulfate, . Originally thought to be a mixed-valence compound, it has been shown to contain cations, analogous to the better-known mercury(I) ion, . A gold(II) complex, the tetraxenonogold(II) cation, which contains xenon as a ligand, occurs in . In September 2023, a novel type of metal-halide perovskite material consisting of Au3+ and Au2+ cations in its crystal structure has been found. It has been shown to be unexpectedly stable at normal conditions.
Gold pentafluoride, along with its derivative anion, , and its difluorine complex, gold heptafluoride, is the sole example of gold(V), the highest verified oxidation state.
Some gold compounds exhibit aurophilicity, which describes the tendency of gold ions to interact at distances that are too long to be a conventional Au–Au bond but shorter than van der Waals bonding. The interaction is estimated to be comparable in strength to that of a hydrogen bond.
Well-defined cluster compounds are numerous. In some cases, gold has a fractional oxidation state. A representative example is the octahedral species .
All three sources involve a process called the r-process (rapid neutron capture), which forms elements heavier than iron. For decades, scientists believed supernova nucleosynthesis was the primary mechanism for gold formation. More recently, research has shown that neutron star collisions produce significant quantities of gold through the r-process.
In August 2017, the spectroscopic signatures of heavy elements, including gold, were directly observed by electromagnetic observatories during the GW170817 neutron star merger event. This confirmed neutron star mergers as a source of gold, after years of only indirect detection."we have no spectroscopic evidence that such elements have truly been produced," wrote author Stephan Rosswog. This single event generated between 3 and 13 of gold, suggesting that neutron star mergers might produce enough gold to account for most of this element in the universe.
However, neutron star mergers alone cannot explain all cosmic gold, particularly in older stars, because these mergers occur relatively late in galactic history and are infrequent (approximately once every 100,000 years). This created a timing paradox in explaining the presence of gold in stars formed early in the universe.
In 2025, researchers resolved this paradox by confirming that giant flares from (highly magnetic neutron stars) are also a significant source of gold formation. Analysis of a 2004 magnetar flare showed these events produce heavy elements through the same r-process as neutron star mergers. The amount of heavy elements created in a single magnetar flare can exceed the mass of Mars. Since magnetars existed earlier in cosmic history and flare more frequently than neutron star mergers occur, they help explain gold's presence in older stars. Scientists estimate magnetar flares may contribute approximately 1–10% of all elements heavier than iron in our galaxy, including gold.
Gold which is reachable by humans has, in one case, been associated with a particular asteroid impact. The asteroid that formed Vredefort impact structure 2.020 billion years ago is often credited with seeding the Witwatersrand basin in South Africa with the richest gold deposits on earth. Meteor craters may hold untapped wealth. Cosmos Magazine (28 July 2008). Retrieved on 12 September 2013. However, this scenario is now questioned. The gold-bearing Witwatersrand rocks were laid down between 700 and 950 million years before the Vredefort impact.McCarthy, T., Rubridge, B. (2005). The Story of Earth and Life. Struik Publishers, Cape Town. pp. 89–90, 102–107, 134–136. Norman, N., Whitfield, G. (2006) Geological Journeys. Struik Publishers, Cape Town. pp. 38–49, 60–61. These gold-bearing rocks had furthermore been covered by a thick layer of Ventersdorp lavas and the Transvaal Basin of rocks before the meteor struck, and thus the gold did not actually arrive in the asteroid/meteorite. What the Vredefort impact achieved, however, was to distort the Witwatersrand basin in such a way that the gold-bearing rocks were brought to the present erosion surface in Johannesburg, on the Witwatersrand, just inside the rim of the original diameter crater caused by the meteor strike. The discovery of the deposit in 1886 launched the Witwatersrand Gold Rush. Some 22% of all the gold that is ascertained to exist today on Earth has been extracted from these Witwatersrand rocks.
Gold sometimes occurs combined with tellurium as the calaverite, krennerite, nagyagite, petzite and sylvanite (see telluride minerals), and as the rare bismuthide maldonite () and antimonide aurostibite (). Gold also occurs in rare alloys with copper, lead, and mercury: the minerals auricupride (), novodneprite () and weishanite ().
A 2004 research paper suggests that microbes can sometimes play an important role in forming gold deposits, transporting and precipitating gold to form grains and nuggets that collect in alluvial deposits. This is doctoral research undertaken by Frank Reith at the Australian National University, published 2004.
A 2013 study has claimed water in faults vaporizes during an earthquake, depositing gold. When an earthquake strikes, it moves along a fault. Water often lubricates faults, filling in fractures and jogs. About below the surface, under very high temperatures and pressures, the water carries high concentrations of carbon dioxide, silica, and gold. During an earthquake, the fault jog suddenly opens wider. The water inside the void instantly vaporizes, flashing to steam and forcing silica, which forms the mineral quartz, and gold out of the fluids and onto nearby surfaces.
A number of people have claimed to be able to economically recover gold from sea water, but they were either mistaken or acted in an intentional deception. Prescott Jernegan ran a gold-from-seawater swindle in the United States in the 1890s, as did an English fraudster in the early 1900s.Plazak, Dan A Hole in the Ground with a Liar at the Top (Salt Lake: Univ. of Utah Press, 2006) (contains a chapter on gold-from seawater swindles) Fritz Haber did research on the extraction of gold from sea water in an effort to help pay Germany's reparations following World War I. Based on the published values of 2 to 64 ppb of gold in seawater, a commercially successful extraction seemed possible. After analysis of 4,000 water samples yielding an average of 0.004 ppb, it became clear that extraction would not be possible, and he ended the project.
The oldest gold artifacts in the world are from Bulgaria and are dating back to the 5th millennium BC (4,600 BC to 4,200 BC), such as those found in the Varna Necropolis near Lake Varna and the Black Sea coast, thought to be the earliest "well-dated" finding of gold artifacts in history.Susan (senior metallurgist in the British Museum Department of Conservation and Scientific Research) La Niece (2009). 9780674035904, Harvard University Press. . ISBN 9780674035904
Gold artifacts probably made their first appearance in Ancient Egypt at the very beginning of the pre-dynastic period, at the end of the fifth millennium BC and the start of the fourth, and smelting was developed during the course of the 4th millennium; gold artifacts appear in the archeology of Lower Mesopotamia during the early 4th millennium.Sutherland, C.H.V, Gold (London, Thames & Hudson, 1959) p 27 ff. As of 1990, gold artifacts found at the Wadi Qana cave cemetery of the 4th millennium BC in West Bank were the earliest from the Levant. Gold artifacts such as the golden hats and the Nebra disk appeared in Central Europe from the 2nd millennium BC Bronze Age.
The oldest known map of a gold mine was drawn in the 19th Dynasty of Ancient Egypt (1320–1200 BC), whereas the first written reference to gold was recorded in the 12th Dynasty around 1900 BC.Pohl, Walter L. (2011) Economic Geology Principles and Practice. Wiley. p. 208. . Egyptian hieroglyphs from as early as 2600 BC describe gold, which King Tushratta of the Mitanni claimed was "more plentiful than dirt" in Egypt. Egypt and especially Nubia had the resources to make them major gold-producing areas for much of history. One of the earliest known maps, known as the Turin Papyrus Map, shows the plan of a gold mine in Nubia together with indications of the local geology. The primitive working methods are described by both Strabo and Diodorus Siculus, and included fire-setting. Large mines were also present across the Red Sea in what is now Saudi Arabia.
Gold is mentioned in the Amarna letters numbered 19Moran, William L., 1987, 1992. The Amarna Letters, pp. 43–46. and 26Moran, William L. 1987, 1992. The Amarna Letters. EA 245, "To the Queen Mother: Some Missing Gold Statues", pp. 84–86. from around the 14th century BC. "Akhenaten" . Encyclopaedia BritannicaDodson, Aidan and Hilton, Dyan (2004). The Complete Royal Families of Ancient Egypt. Thames & Hudson.
Gold is mentioned frequently in the Old Testament, starting with Genesis 2:11 (at Havilah), the story of the golden calf, and many parts of the temple including the Menorah and the golden altar. In the New Testament, it is included with the gifts of the magi in the first chapters of Matthew. The Book of Revelation 21:21 describes the city of New Jerusalem as having streets "made of pure gold, clear as crystal". Exploitation of gold in the south-east corner of the Black Sea is said to date from the time of Midas, and this gold was important in the establishment of what is probably the world's earliest coinage in Lydia around 610 BC. The legend of the golden fleece dating from eighth century BCE may refer to the use of fleeces to trap gold dust from in the ancient world. From the 6th or 5th century BC, the Chu (state) circulated the Ying Yuan, one kind of square gold coin.
In Roman metallurgy, new methods for extracting gold on a large scale were developed by introducing hydraulic mining methods, especially in Hispania from 25 BC onwards and in Dacia from 106 AD onwards. One of their largest mines was at Las Medulas in León, where seven long aqueducts enabled them to sluice most of a large alluvial deposit. The mines at Roşia Montană in Transylvania were also very large, and until very recently, still mined by opencast methods. They also exploited smaller deposits in Roman Britain, such as placer and hard-rock deposits at Dolaucothi. The various methods they used are well described by Pliny the Elder in his encyclopedia Naturalis Historia written towards the end of the first century AD.
During Mansa Musa's (ruler of the Mali Empire from 1312 to 1337) hajj to Mecca in 1324, he passed through Cairo in July 1324, and was reportedly accompanied by a camel train that included thousands of people and nearly a hundred camels where he gave away so much gold that it depressed the price in Egypt for over a decade, causing high inflation. Mansa Musa. Black History Pages A contemporary Arab historian remarked:
The European exploration of the Americas was fueled in no small part by reports of the gold ornaments displayed in great profusion by Native American peoples, especially in Mesoamerica, Peru, Ecuador and Colombia. The regarded gold as the product of the gods, calling it literally "god excrement" ( teocuitlatl in Nahuatl), and after Moctezuma II was killed, most of this gold was shipped to Spain. (1992). 9780520062344, University of California Press. ISBN 9780520062344 However, for the indigenous peoples of North America gold was considered useless and they saw much greater value in other minerals which were directly related to their utility, such as obsidian, flint, and slate. Sierra Nevada Virtual Museum. Sierra Nevada Virtual Museum. Retrieved on 4 May 2012.
El Dorado is applied to a legendary story in which precious stones were found in fabulous abundance along with gold coins. The concept of El Dorado underwent several transformations, and eventually accounts of the previous myth were also combined with those of a legendary lost city. El Dorado, was the term used by the Spanish Empire to describe a mythical tribal chief (zipa) of the Muisca native people in Colombia, who, as an initiation rite, covered himself with gold dust and submerged in Lake Guatavita. The legends surrounding El Dorado changed over time, as it went from being a man, to a city, to a kingdom, and then finally to an empire.
Beginning in the early modern period, European exploration and colonization of West Africa was driven in large part by reports of gold deposits in the region, which was eventually referred to by Europeans as the "Gold Coast". From the late 15th to early 19th centuries, European trade in the region was primarily focused in gold, along with ivory and slaves. The gold trade in West Africa was dominated by the Ashanti Empire, who initially traded with the Portuguese before branching out and trading with British Empire, French, Spanish Empire and Danish merchants. (2019). 9780241003282 ISBN 9780241003282 British desires to secure control of West African gold deposits played a role in the Anglo-Ashanti wars of the late 19th century, which saw the Ashanti Empire annexed by Britain.
Gold played a role in western culture, as a cause for desire and of corruption, as told in children's such as Rumpelstiltskin—where Rumpelstiltskin turns hay into gold for the peasant's daughter in return for her child when she becomes a princess—and the stealing of the hen that lays golden eggs in Jack and the Beanstalk.
The top prize at the Olympic Games and many other sports competitions is the gold medal.
75% of the presently accounted for gold has been extracted since 1910, two-thirds since 1950.
One main goal of the alchemy was to produce gold from other substances, such as lead — presumably by the interaction with a mythical substance called the philosopher's stone. Trying to produce gold led the alchemists to systematically find out what can be done with substances, and this laid the foundation for today's chemistry, which can produce gold (albeit uneconomically) by using nuclear transmutation. Their symbol for gold was the circle with a point at its center (☉), which was also the astrology symbol and the ancient Chinese character for the Sun.
The Dome of the Rock is covered with an ultra-thin golden glassier. The Sikh Golden temple, the Harmandir Sahib, is a building covered with gold. Similarly the Wat Phra Kaew emerald Buddhism temple (wat) in Thailand has ornamental gold-leafed statues and roofs. Some European king and queen's crowns were made of gold, and gold was used for the bridal crown since antiquity. An ancient Talmudic text circa 100 AD describes Rachel, wife of Rabbi Akiva, receiving a "Jerusalem of Gold" (diadem). A Greek burial crown made of gold was found in a grave circa 370 BC.
(2025). 9780714150765, The British Museum Press. ISBN 9780714150765
Statuette of Amun MET DT553.jpg| statuette of Amun, 945–715 BC, gold, Metropolitan Museum of Art
Anillo de Sheshonq (46627183381).jpg|Ancient Egyptian signet ring, 664–525 BC, gold, British Museum
File:Openwork dagger handle-IMG 4418-black.jpg|Ancient China cast openwork dagger hilt, 6th–5th centuries BC, gold, British Museum (2025). 9780714150765, The British Museum Press. ISBN 9780714150765
Gold stater MET DP138743.jpg|Ancient Greece stater, 323–315 BC, gold, Metropolitan Museum of Art
Gold funerary wreath MET DP257471.jpg|Etruscans funerary wreath, 4th–3rd century BC, gold, Metropolitan Museum of Art
Gold aureus of Hadrian MET DP104782b.jpg|Roman Empire aureus of Hadrian, 134–138 AD, gold, Metropolitan Museum of Art
Lime Container (Poporo) MET DT1262.jpg|Quimbaya lime container, 5th–9th century, gold, Metropolitan Museum of Art
File:British Museum - Room 41 (20626313758).jpg|Anglo-Saxon art belt buckle from Sutton Hoo with a niello interlace pattern, 7th century, gold, British Museum (2025). 9780714150765, The British Museum Press. ISBN 9780714150765
Byzantium, 11th century - Scyphate - 2001.25 - Cleveland Museum of Art.tif|Byzantine empire scyphate, 1059–1067, gold, Cleveland Museum of Art, Cleveland, Ohio, USA
Double Bat-Head Figure Pendant MET DT935.jpg|Pre-Columbian pendant with two bat-head warriors who carry spears, 11th–16th century, gold, Metropolitan Museum of Art
File:AHOTWgold lama.JPG|Inca Empire hollow model of a llama, 14th-15th centuries, gold, British Museum (2025). 9780714150765, The British Museum Press. ISBN 9780714150765
File:The Judgement of Paris, Waddeson Bequest.jpg|Renaissance art hat badge that shows the Judgment of Paris, 16th century, enamelled gold, British Museum (2025). 9780714150765, The British Museum Press. ISBN 9780714150765
Box with scene depicting Roman hero Gaius Mucius Scaevola before the Etruscan king Lars Porsena MET DP170836 (cropped).jpg|Rococo box, by George Michael Moser, 1741, gold, Metropolitan Museum of Art
Jean Joseph de Saint-Germain - Candelabrum - 1946.81 - Cleveland Museum of Art.tif|Rococo candelabrum, by Jean Joseph de Saint-Germain, 1750, gilt bronze, Cleveland Museum of Art
Tabatière Minerve, Mercure, Pégase (Louvre, OA 2121).jpg|Rococo snuff box with Minerva, by Jean-Malquis Lequin, 1750–1752, gold and painted enamel, Louvre
File:Tabatière J-Frémin (Louvre, OA 6857).jpg|Louis XVI style snuff box, by Jean Frémin, 1763–1764, gold and painted enamel, Louvre
File:Washstand (athénienne or lavabo) MET DP106594.jpg|Neoclassicism washstand (athénienne or lavabo), 1800–1814, legs, base and shelf of yew wood, gilt bronze mounts, iron plate beneath shelf, Metropolitan Museum of Art
File:Clock, French, circa 1835-1840, gilt and patinated bronze, inherited from Maurice Quentin Bauchart, 1911, inv. 17741, Museum of Decorative Arts, Paris.jpg|Gothic Revival clock, unknown French maker, 1835-1840, gilt and patinated bronze, Museum of Decorative Arts, Paris
File:Teapot, by Alphonse Debain, from Paris, 1900, gilt silver and ivory, inv. 2021.63.1 MAD Paris.jpg|Art Nouveau teapot, by Alphonse Debain, gilt silver and ivory, Museum of Decorative Arts
Aristotle in his ethics used gold symbolism when referring to what is now known as the golden mean. Similarly, gold is associated with perfect or divine principles, such as in the case of the golden ratio and the Golden Rule. Gold is further associated with the wisdom of aging and fruition. The fiftieth wedding anniversary is golden. A person's most valued or most successful latter years are sometimes considered "golden years" or "golden jubilee". The height of a civilization is referred to as a golden age.Lubna Umar and Sarwet Rasul, "Critical Metaphor Analysis: Nawaz Sharif and the Myth of a Golden Time" NUML Journal of Critical Inquiry 15#2, (Dec 2017): 78–102.
In some forms of Christianity and Judaism, gold has been associated both with the sacred and evil. In the Book of Exodus, the Golden Calf is a symbol of idolatry, while in the Book of Genesis, Abraham was said to be rich in gold and silver, and Moses was instructed to cover the Mercy Seat of the Ark of the Covenant with pure gold. In Byzantine the halos of Christ, Virgin Mary and the saints are often golden.
In Islam, gold (along with silk) is often cited as being forbidden for men to wear. Abu Bakr al-Jazaeri, quoting a hadith, said that "the wearing of silk and gold are forbidden on the males of my nation, and they are lawful to their women". This, however, has not been enforced consistently throughout history, e.g. in the Ottoman Empire. Further, small gold accents on clothing, such as in embroidery, may be permitted.
In ancient Greek religion and Greek mythology, Theia was seen as the goddess of gold, silver and other . (1992). 9781604134124, Chelsea House Publishers. ISBN 9781604134124
According to Christopher Columbus, those who had something of gold were in possession of something of great value on Earth and a substance to even help souls to paradise.
are typically made of gold. It is long lasting and unaffected by the passage of time and may aid in the ring symbolism of eternal vows before God and the perfection the marriage signifies. In Orthodox Christian wedding ceremonies, the wedded couple is adorned with a golden crown (though some opt for wreaths, instead) during the ceremony, an amalgamation of symbolic rites.
On 24 August 2020, archaeologists discovered a trove of early gold coins near the central city of Yavne. Analysis of the extremely rare collection of 425 gold coins indicated that they were from the late 9th century. Dating to around 1,100 years back, the gold coins were from the Abbasid Caliphate.
In 2023, China was the world's leading gold-mining country, followed in order by Russia, Australia, Canada, the United States and Ghana.
In South America, the controversial project Pascua Lama aims at exploitation of rich fields in the high mountains of Atacama Desert, at the border between Chile and Argentina.
It has been estimated that up to one-quarter of the yearly global gold production originates from artisanal or small scale mining.
The city of Johannesburg located in South Africa was founded as a result of the Witwatersrand Gold Rush which resulted in the discovery of some of the largest natural gold deposits in recorded history. The gold fields are confined to the northern and north-western edges of the Witwatersrand basin, which is a thick layer of archean rocks located, in most places, deep under the Free State, Gauteng and surrounding provinces.Truswell, J.F. (1977). The Geological Evolution of South Africa. pp. 21–28. Purnell, Cape Town. These Witwatersrand rocks are exposed at the surface on the Witwatersrand, in and around Johannesburg, but also in isolated patches to the south-east and south-west of Johannesburg, as well as in an arc around the Vredefort Dome which lies close to the center of the Witwatersrand basin. From these surface exposures the basin dips extensively, requiring some of the mining to occur at depths of nearly , making them, especially the Savuka Mine and TauTona mines to the south-west of Johannesburg, the deepest mines on Earth. The gold is found only in six areas where archean rivers from the north and north-west formed extensive pebbly Braided river deltas before draining into the "Witwatersrand sea" where the rest of the Witwatersrand sediments were deposited.
The Second Boer War of 1899–1901 between the British Empire and the Afrikaner was at least partly over the rights of miners and possession of the gold wealth in South Africa.
During the 19th century, occurred whenever large gold deposits were discovered. The first documented discovery of gold in the United States was at the Reed Gold Mine near Georgeville, North Carolina in 1803. The first major gold strike in the United States occurred in a small north Georgia town called Dahlonega. Further gold rushes occurred in California, Colorado, the Black Hills, Otago in New Zealand, a number of locations across Australia, Witwatersrand in South Africa, and the Klondike in Canada.
Grasberg mine located in Papua, Indonesia is the largest gold mining in the world.
The average gold mining and extraction costs were about $317 per troy ounce in 2007, but these can vary widely depending on mining type and ore quality; global mine production amounted to 2,471.1 tonnes.
After initial production, gold is often subsequently refined industrially by the Wohlwill process which is based on electrolysis or by the Miller process, that is chlorination in the melt. The Wohlwill process results in higher purity, but is more complex and is only applied in small-scale installations. Other methods of assaying and purifying smaller amounts of gold include parting and inquartation as well as cupellation, or refining methods based on the dissolution of gold in aqua regia.
As of 2020, the amount of carbon dioxide produced in mining a kilogram of gold is 16 tonnes, while recycling a kilogram of gold produces 53 kilograms of equivalent. Approximately 30 percent of the global gold supply is recycled and not mined as of 2020.
| + Gold jewelry consumption by country (in tonnes) |
| 974 |
| 1120.1 |
| 190 |
| 175.2 |
| 72.2 |
| 73.3 |
| 77.1 |
| 57.3 |
| 68 |
| 23.4 |
| 24.6 |
| 21.3 |
| 17.5 |
| 92.2 |
| 140.1 |
| 3126.1 |
| 450.7 |
| 3576.8 |
According to the World Gold Council, China was the world's largest single consumer of gold in 2013, overtaking India.
Low-grade gold ore may contain less than one ppm gold metal; such ore is ground and mixed with sodium cyanide to dissolve the gold. Cyanide is a highly poisonous chemical, which can kill living creatures when exposed in minute quantities. Many cyanide spills Cyanide spills from gold mine compared to Chernobyl's nuclear disaster . Deseretnews.com (14 February 2000). Retrieved on 4 May 2012. from gold mines have occurred in both developed and developing countries which killed aquatic life in long stretches of affected rivers. Environmentalists consider these events major environmental disasters. Death of a river . BBC News (15 February 2000). Retrieved on 4 May 2012. Cyanide spill second only to Chernobyl . Abc.net.au. 11 February 2000. Retrieved on 4 May 2012. Up to thirty tons of used ore can be dumped as waste for producing one troy ounce of gold. Behind gold's glitter, torn lands and pointed questions , The New York Times, 24 October 2005 Gold ore dumps are the source of many heavy elements such as cadmium, lead, zinc, copper, arsenic, selenium and mercury. When sulfide-bearing minerals in these ore dumps are exposed to air and water, the sulfide transforms into sulfuric acid which in turn dissolves these heavy metals facilitating their passage into surface water and ground water. This process is called acid mine drainage. These gold ore dumps contain long-term, highly hazardous waste.
It was once common to use mercury to recover gold from ore, but today the use of mercury is largely limited to small-scale individual miners. Minute quantities of mercury compounds can reach water bodies, causing heavy metal contamination. Mercury can then enter into the human food chain in the form of methylmercury. Mercury poisoning in humans can cause severe brain damage.
Gold extraction is also a highly energy-intensive industry, extracting ore from deep mines and grinding the large quantity of ore for further chemical extraction requires nearly 25 Kilowatt-hour of electricity per gram of gold produced.
The first known coins containing gold were struck in Lydia, Asia Minor, around 600 BC. The talent coin of gold in use during the periods of Grecian history both before and during the time of the life of Homer weighed between 8.42 and 8.75 grams. From an earlier preference in using silver, European economies re-established the minting of gold as coinage during the thirteenth and fourteenth centuries.
Bills (that mature into gold coin) and gold certificates (convertible into gold coin at the issuing bank) added to the circulating stock of gold standard money in most 19th century industrial economies. In preparation for World War I the warring nations moved to fractional gold standards, inflating their currencies to finance the war effort. Post-war, the victorious countries, most notably Britain, gradually restored gold-convertibility, but international flows of gold via bills of exchange remained embargoed; international shipments were made exclusively for bilateral trades or to pay war reparations.
After World War II gold was replaced by a system of nominally convertible currencies related by fixed exchange rates following the Bretton Woods system. and the direct convertibility of currencies to gold have been abandoned by world governments, led in 1971 by the United States' refusal to redeem its dollars in gold. Fiat currency now fills most monetary roles. Switzerland was the last country to tie its currency to gold; this was ended by a referendum in 1999.
Central banks continue to keep a portion of their liquid reserves as gold in some form, and metals exchanges such as the London Bullion Market Association still clear transactions denominated in gold, including future delivery contracts. Today, gold mining output is declining. With the sharp growth of economies in the 20th century, and increasing foreign exchange, the world's and their trading market have become a small fraction of all markets and fixed exchange rates of currencies to gold have been replaced by floating prices for gold and gold Futures contract. Though the gold stock grows by only 1% or 2% per year, very little metal is irretrievably consumed. Inventory above ground would satisfy many decades of industrial and even artisan uses at current prices.
The gold proportion (fineness) of alloys is measured by karat (k). Pure gold (commercially termed fine gold) is designated as 24 karat, abbreviated 24k. English gold coins intended for circulation from 1526 into the 1930s were typically a standard 22k alloy called crown gold, for hardness (American gold coins for circulation after 1837 contain an alloy of 0.900 fine gold, or 21.6 kt).
Often the prices of various platinum group metals can be much higher than gold, although gold has been used as a standard for currency to a greater degree than the platinum group metals. Gold has been used as a symbol for purity, value, royalty, and particularly roles that combine these properties. Gold as a sign of wealth and prestige was ridiculed by Thomas More in his treatise Utopia. On that imaginary island, gold is so abundant that it is used to make chains for slaves, tableware, and lavatory seats. When ambassadors from other countries arrive, dressed in ostentatious gold jewels and badges, the Utopians mistake them for menial servants, paying homage instead to the most modestly dressed of their party.
The ISO 4217 currency code of gold is XAU. Many holders of gold store it in form of bullion coins or gold bar as a hedge against inflation or other economic disruptions. A paper by the National Bureau of Economic Research found that gold may be reliable as an inflation hedge over long timescales (centuries) but not over practical timescales. Modern for investment or collector purposes do not require good mechanical wear properties; they are typically fine gold at 24k, although the American Gold Eagle and the British gold sovereign continue to be minted in 22k (0.92) metal in historical tradition, and the South African Krugerrand, first released in 1967, is also 22k (0.92).
The special issue Canadian Gold Maple Leaf coin contains the highest purity gold of any bullion coin, at 99.999% or 0.99999, while the popular issue Canadian Gold Maple Leaf coin has a purity of 99.99%. In 2006, the United States Mint began producing the American Buffalo gold bullion coin with a purity of 99.99%. The Gold Kangaroos were first coined in 1986 as the Australian Gold Nugget but changed the reverse design in 1989. Other modern coins include the Vienna Philharmonic bullion coin and the Chinese Gold Panda.
The price of gold is determined through trading in the gold and derivatives markets, but a procedure known as the Gold Fixing in London, originating in September 1919, provides a daily benchmark price to the industry. The afternoon fixing was introduced in 1968 to provide a price when US markets are open. , gold was valued at around $127 per gram ($3,950 per troy ounce).
The largest gold depository in the world is that of the U.S. Federal Reserve Bank in New York, which holds about 3% of the gold known to exist and accounted for today, as does the similarly laden U.S. Bullion Depository at Fort Knox. In 2005 the World Gold Council estimated total global gold supply to be 3,859 tonnes and demand to be 3,754 tonnes, giving a surplus of 105 tonnes.
After 15 August 1971 Nixon shock, the price began to greatly increase, and between 1968 and 2000 the price of gold ranged widely, from a high of $850 per troy ounce ($27.33/g) on 21 January 1980, to a low of $252.90 per troy ounce ($8.13/g) on 21 June 1999 (London Gold Fixing). Kitco.com , Gold – London PM Fix 1975 – present (GIF), Retrieved 22 July 2006. Prices increased rapidly from 2001, but the 1980 high was not exceeded until 3 January 2008, when a new maximum of $865.35 per troy weight was set. Another record price was set on 17 March 2008, at $1023.50 per troy ounce ($32.91/g).
On 2 December 2009, gold reached a new high closing at $1,217.23. Gold further rallied hitting new highs in May 2010 after the European Union debt crisis prompted further purchase of gold as a safe asset. On 1 March 2011, gold hit a new all-time high of $1432.57, based on investor concerns regarding ongoing Arab Spring in North Africa as well as in the Middle East.
From April 2001 to August 2011, spot gold prices more than quintupled in value against the US dollar, hitting a new all-time high of $1,913.50 on 23 August 2011, prompting speculation that the long secular bear market had ended and a bull market had returned. However, the price then began a slow decline towards $1200 per troy ounce in late 2014 and 2015.
In August 2020, the gold price picked up to US$2060 per ounce after a total growth of 59% from August 2018 to October 2020, a period during which it outplaced the Nasdaq total return of 54%.
Gold futures are traded on the COMEX exchange. These contacts are priced in USD per troy ounce (1 troy ounce = 31.1034768 grams). Below are the CQG contract specifications outlining the futures contracts:
| +Contract Specifications !Gold (GCA) ! | |
| Exchange: | COMEX |
| Sector: | Metal |
| Tick Size: | 0.1 |
| Tick Value: | 10 USD |
| BPV: | 100 |
| Denomination: | USD |
| Decimal Place: | 1 |
Gold solder is used for joining the components of gold jewelry by high-temperature hard soldering or brazing. If the work is to be of quality, the gold solder alloy must match the fineness of the work, and alloy formulas are manufactured to color-match yellow and white gold. Gold solder is usually made in at least three melting-point ranges referred to as Easy, Medium and Hard. By using the hard, high-melting point solder first, followed by solders with progressively lower melting points, goldsmiths can assemble complex items with several separate soldered joints. Gold can also be made into gold thread and used in embroidery.
Though gold is attacked by free chlorine, its good conductivity and general resistance to oxidation and corrosion in other environments (including resistance to non-chlorinated acids) has led to its widespread industrial use in the electronic era as a thin-layer coating on electrical connectors, thereby ensuring good connection. For example, gold is used in the connectors of the more expensive electronics cables, such as audio, video and USB cables. The benefit of using gold over other connector metals such as tin in these applications has been debated; gold connectors are often criticized by audio-visual experts as unnecessary for most consumers and seen as simply a marketing ploy. However, the use of gold in other applications in electronic sliding contacts in highly humid or corrosive atmospheres, and in use for contacts with a very high failure cost (certain , communications equipment, spacecraft, jet aircraft engines) remains very common. (2025). 9780415937344, Routledge. ISBN 9780415937344
Besides sliding electrical contacts, gold is also used in electrical contacts because of its resistance to corrosion, electrical conductivity, ductile and lack of toxicity. Switch contacts are generally subjected to more intense corrosion stress than are sliding contacts. Fine gold wires are used to connect semiconductor devices to their packages through a process known as wire bonding.
The concentration of free electrons in gold metal is 5.91×1022 cm−3. Gold is highly conductive to electricity and has been used for electrical wiring in some high-energy applications (only silver and copper are more conductive per volume, but gold has the advantage of corrosion resistance). For example, gold electrical wires were used during some of the Manhattan Project's atomic experiments, but large high-current silver wires were used in the calutron isotope separator magnets in the project.
It is estimated that 16% of the world's presently-accounted-for gold and 22% of the world's silver is contained in electronic technology in Japan.
Some esotericists and forms of alternative medicine assign metallic gold a healing power, against the scientific consensus.
Historically, metallic and gold compounds have long been used for medicinal purposes. Gold, usually as the metal, is perhaps the most anciently administered medicine (apparently by shamanic practitioners) and known to Dioscorides.Mortier, Tom. An experimental study on the preparation of gold nanoparticles and their properties , PhD thesis, University of Leuven (May 2006) In medieval times, gold was often seen as beneficial for the health, in the belief that something so rare and beautiful could not be anything but healthy.
In the 19th century gold had a reputation as an anxiolytic, a therapy for nervous disorders. Depression, epilepsy, migraine, and glandular problems such as amenorrhea and impotence were treated, and most notably alcoholism (Keeley, 1897).
The apparent paradox of the actual toxicology of the substance suggests the possibility of serious gaps in the understanding of the action of gold in physiology. Only salts and radioisotopes of gold are of pharmacological value, since elemental (metallic) gold is inert to all chemicals it encounters inside the body (e.g., ingested gold cannot be attacked by stomach acid).
Gold alloys are used in restorative dentistry, especially in tooth restorations, such as crowns and permanent bridges. The gold alloys' slight malleability facilitates the creation of a superior molar mating surface with other teeth and produces results that are generally more satisfactory than those produced by the creation of porcelain crowns. The use of gold crowns in more prominent teeth such as incisors is favored in some cultures and discouraged in others.
Colloidal gold preparations (suspensions of gold nanoparticles) in water are intensely red-, and can be made with tightly controlled particle sizes up to a few tens of nanometers across by reduction of gold chloride with citrate or ascorbate ions. Colloidal gold is used in research applications in medicine, biology and materials science. The technique of immunogold labeling exploits the ability of the gold particles to adsorb protein molecules onto their surfaces. Colloidal gold particles coated with specific antibodies can be used as probes for the presence and position of antigens on the surfaces of cells. In ultrathin sections of tissues viewed by electron microscopy, the immunogold labels appear as extremely dense round spots at the position of the antigen.
Gold, or alloys of gold and palladium, are applied as conductive coating to biological specimens and other non-conducting materials such as plastics and glass to be viewed in a scanning electron microscope. The coating, which is usually applied by sputtering with an argon plasma, has a triple role in this application. Gold's very high electrical conductivity drains electric charge to earth, and its very high density provides stopping power for electrons in the electron beam, helping to limit the depth to which the electron beam penetrates the specimen. This improves definition of the position and topography of the specimen surface and increases the spatial resolution of the image. Gold also 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.
The isotope gold-198 (half-life 2.7 days) is used in nuclear medicine, in some cancer treatments and for treating other diseases.
Soluble compounds (gold salts) such as gold chloride are toxic to the liver and kidneys. Common cyanide salts of gold such as potassium gold cyanide, used in gold electroplating, are toxic by virtue of both their cyanide and gold content. There are rare cases of lethal gold poisoning from potassium gold cyanide. Gold toxicity can be ameliorated with chelation therapy with an agent such as dimercaprol.
Gold metal was voted Allergen of the Year in 2001 by the American Contact Dermatitis Society; gold contact allergies affect mostly women. Despite this, gold is a relatively non-potent contact allergen, in comparison with metals like nickel.
A sample of the fungus Aspergillus niger was found growing from gold mining solution; and was found to contain cyano metal complexes, such as gold, silver, copper, iron and zinc. The fungus also plays a role in the solubilization of heavy metal sulfides.
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