A gold coin is a

coin A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order t ...

that is made mostly or entirely of gold. Most gold coins minted since 1800 are 90–92% gold (22

karat The fineness of a precious metal object (coin, bar, jewelry, etc.) represents the weight of ''fine metal'' therein, in proportion to the total weight which includes alloying base metals and any impurities. Alloy metals are added to increase hardn ...

), while most of today's gold bullion coins are pure gold, such as the

Britannia Britannia () is the national personification of Britain as a helmeted female warrior holding a trident and shield. An image first used in classical antiquity, the Latin ''Britannia'' was the name variously applied to the British Isles, Great ...

Canadian Maple Leaf The Canadian Maple Leaf coins are bullion coins of gold, silver, platinum, or palladium, issued by the Royal Canadian Mint: * Canadian Gold Maple Leaf The Canadian Gold Maple Leaf (GML) is a gold bullion coin that is issued annually by the Gove ...

, and

American Buffalo American Buffalo may refer to: *American Buffalo (play), ''American Buffalo'' (play), a play by David Mamet *American Buffalo (film), ''American Buffalo'' (film), a 1996 film of Mamet's play directed by Michael Corrente *American Buffalo (coin), a ...

. Alloyed gold coins, like the

American Gold Eagle The American Gold Eagle is an official gold bullion coin of the United States. Authorized under the Gold Bullion Coin Act of 1985, it was first released by the United States Mint in 1986. Because the term "eagle" also is the official United ...

and South African

Krugerrand The Krugerrand (; ) is a South African coin, first minted on 3 July 1967 to help market South African gold and produced by Rand Refinery and the South African Mint. The name is a compound of ''Paul Kruger'', the former President of the South Af ...

, are typically 91.7% gold by weight, with the remainder being silver and copper. Traditionally (up to about the 1930s), gold coins have been circulation coins, including coin-like

bracteate A bracteate (from the Latin ''bractea'', a thin piece of metal) is a flat, thin, single-sided gold medal worn as jewelry that was produced in Northern Europe predominantly during the Migration Period of the Germanic Iron Age (including the Vende ...

s and

dinars The dinar () is the principal currency unit in several countries near the Mediterranean Sea, and its historical use is even more widespread. The modern dinar's historical antecedents are the gold dinar and the silver dirham, the main coin of ...

. In recent decades, however, gold coins are mainly produced as

bullion coin Bullion is non-ferrous metal that has been refined to a high standard of elemental purity. The term is ordinarily applied to bulk metal used in the production of coins and especially to precious metals such as gold and silver. It comes from the ...

s for

investors An investor is a person who allocates financial capital with the expectation of a future return (profit) or to gain an advantage (interest). Through this allocated capital most of the time the investor purchases some species of property. Type ...

and as

commemorative coin Commemorative coins are coins issued to commemorate some particular event or issue with a distinct design with reference to the occasion on which they were issued. Many coins of this category serve as collectors items only, although some countries ...

s for

collectors Collector(s) may refer to: Arts and entertainment * Collector (character), a fictional character in the Marvel Comics universe * ''Collector'' (2011 film), a 2011 Indian Malayalam film * ''Collector'' (2016 film), a 2016 Russian film * ''Collec ...

. While modern gold coins are still

legal tender Legal tender is a form of money that courts of law are required to recognize as satisfactory payment for any monetary debt. Each jurisdiction determines what is legal tender, but essentially it is anything which when offered ("tendered") in pa ...

, they are not observed in everyday

financial transaction A financial transaction is an agreement, or communication, between a buyer and seller to exchange goods, services, or assets for payment. Any transaction involves a change in the status of the finances of two or more businesses or individuals. A ...

s, as the metal value normally exceeds the

nominal value In economics, nominal value is measured in terms of money, whereas real value is measured against goods or services. A real value is one which has been adjusted for inflation, enabling comparison of quantities as if the prices of goods had not c ...

. For example, the

has a denomination of 10

USD The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...

, but a metal value of more than $800 USD (being around a half an ounce). The

gold reserve A gold reserve is the gold held by a national central bank, intended mainly as a guarantee to redeem promises to pay depositors, note holders (e.g. paper money), or trading peers, during the eras of the gold standard, and also as a store of v ...

s of

central bank A central bank, reserve bank, or monetary authority is an institution that manages the currency and monetary policy of a country or monetary union, and oversees their commercial banking system. In contrast to a commercial bank, a central ba ...

s are dominated by

gold bar A gold bar, also called gold bullion or gold ingot, is a quantity of refined metallic gold of any shape that is made by a bar producer meeting standard conditions of manufacture, labeling, and record keeping. Larger gold bars that are produced ...

s, but gold coins may occasionally contribute. Gold has been used as money for many reasons. It is

fungible In economics, fungibility is the property of a good or a commodity whose individual units are essentially interchangeable, and each of whose parts is indistinguishable from any other part. Fungible tokens can be exchanged or replaced; for exam ...

, with a low

spread Spread may refer to: Places * Spread, West Virginia Arts, entertainment, and media * ''Spread'' (film), a 2009 film. * ''$pread'', a quarterly magazine by and for sex workers * "Spread", a song by OutKast from their 2003 album ''Speakerboxxx/T ...

between the prices to buy and sell. Gold is also easily transportable, as it has a high value-to-weight ratio compared to other

commodities In economics, a commodity is an economic good, usually a resource, that has full or substantial fungibility: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them. The price of a comm ...

such as silver. Gold can be re-coined, divided into smaller units, or melted into larger units such as gold bars, without destroying its metal value. The

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

of gold is higher than most other metals, making it difficult to pass

counterfeit To counterfeit means to imitate something authentic, with the intent to steal, destroy, or replace the original, for use in illegal transactions, or otherwise to deceive individuals into believing that the fake is of equal or greater value tha ...

s. Additionally, gold is extremely unreactive chemically: it does not tarnish or corrode over time.

History

Antiquity

Gold Solidus of Valentinian II - obverse YORYM 1998 853

Gold was used in commerce (beside other precious metals) in the

Ancient Near East The ancient Near East was the home of early civilizations within a region roughly corresponding to the modern Middle East: Mesopotamia (modern Iraq, southeast Turkey, southwest Iran and northeastern Syria), ancient Egypt, ancient Iran ( Elam, ...

since the

Bronze Age The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second pri ...

, but

s proper originated much later, during the 6th century BC, in

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

. The name of king

Croesus Croesus ( ; Lydian: ; Phrygian: ; grc, Κροισος, Kroisos; Latin: ; reigned: c. 585 – c. 546 BC) was the king of Lydia, who reigned from 585 BC until his defeat by the Persian king Cyrus the Great in 547 or 546 BC. Croesus was ...

Lydia Lydia (Lydian language, Lydian: ‎𐤮𐤱𐤠𐤭𐤣𐤠, ''Śfarda''; Aramaic: ''Lydia''; el, Λυδία, ''Lȳdíā''; tr, Lidya) was an Iron Age Monarchy, kingdom of western Asia Minor located generally east of ancient Ionia in the mod ...

remains associated with the invention (although the

Parian Chronicle The Parian Chronicle or Parian Marble ( la, Marmor Parium, Mar. Par.) is a Greek chronology, covering the years from 1582 BC to 299 BC, inscribed on a stele. Found on the island of Paros in two sections, and sold in Smyrna in the early 17 ...

mentions

Pheidon Pheidon (Greek: Φείδων) was an Argive ruler during the 7th century BCE and 10th in line to Temenus. He was arguably Argos's most ambitious and successful ruler during the 7th century BCE. There is a possibility that there were in fact two di ...

Argos Argos most often refers to: * Argos, Peloponnese, a city in Argolis, Greece ** Ancient Argos, the ancient city * Argos (retailer), a catalogue retailer operating in the United Kingdom and Ireland Argos or ARGOS may also refer to: Businesses * ...

as a contender). In 546 BC, Croesus was captured by the

Persians The Persians are an Iranian ethnic group who comprise over half of the population of Iran. They share a common cultural system and are native speakers of the Persian language as well as of the languages that are closely related to Persian. ...

, who adopted gold as the main metal for their coins. The most valuable of all Persian minted coinage still remains the gold drams, minted in 1 AD as a gift by the Persian King Vonones (Matthew 2.1–23).

Ancient Greek coinage The history of ancient Greek coinage can be divided (along with most other Greek art forms) into four periods: the Archaic, the Classical, the Hellenistic and the Roman. The Archaic period extends from the introduction of coinage to the Greek ...

contained a number of gold coins issued by the various city states. The

Ying yuan Ying Yuan () were stamped blocks of gold bullion. This was an early form of currency that could be considered a precursor to gold coins. They were issued by the ancient Chinese state of Chu during the Warring States period between the 400s and lat ...

is an early gold coin minted in ancient China. The oldest ones known are from about the 5th or 6th century BC. Larger units such as the various talent measures (26 to up to 60 kg) were used for high value exchanges (similar to today's 400-troy-ounce (12.4 kg) "good delivery" gold

bullion Bullion is non-ferrous metal that has been refined to a high standard of elemental purity. The term is ordinarily applied to bulk metal used in the production of coins and especially to precious metals such as gold and silver. It comes from t ...

bar).

Middle Ages and Early Modern period

Modern history

The

German gold mark The German mark (german: Goldmark ; sign: ℳ) was the currency of the German Empire, which spanned from 1871 to 1918. The mark was paired with the minor unit of the pfennig (₰); 100 pfennigs were equivalent to 1 mark. The mark was on the g ...

was introduced in 1873 in the

German Empire The German Empire (),Herbert Tuttle wrote in September 1881 that the term "Reich" does not literally connote an empire as has been commonly assumed by English-speaking people. The term literally denotes an empire – particularly a hereditary ...

, replacing the various local

Gulden ''Gulden'' is the historical German and Dutch term for gold coin (from Middle High German "golden penny" and Middle Dutch " golden florin"), equivalent to the English term guilder. Gulden, Gülden, Guldens or Gulden's may also refer to: Coins o ...

coins of the

Holy Roman Empire The Holy Roman Empire was a Polity, political entity in Western Europe, Western, Central Europe, Central, and Southern Europe that developed during the Early Middle Ages and continued until its Dissolution of the Holy Roman Empire, dissolution i ...

. Gold coins then had a very long period as a primary form of money, only falling into disuse in the early 20th century. Most of the world stopped making gold coins as currency by 1933, as countries switched from the

gold standard A gold standard is a monetary system in which the standard economic unit of account is based on a fixed quantity of gold. The gold standard was the basis for the international monetary system from the 1870s to the early 1920s, and from the la ...

due to hoarding during the worldwide economic crisis of the

Great Depression The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...

. In the United States, 1933's

Executive Order 6102 Executive Order 6102 is an executive order signed on April 5, 1933, by US President Franklin D. Roosevelt "forbidding the hoarding of gold coin, gold bullion, and gold certificates within the continental United States." The executive order was ...

forbade the hoarding of gold and was followed by a devaluation of the dollar relative to gold, although the United States did not completely uncouple the dollar from the value of gold until 1971. Gold-colored coins have made a comeback in many currencies. However, "gold coin" (in numismatic terminology) always refers to a coin that is (more or less) made of gold, and does not include coins made of

manganese brass Brass is an alloy of copper (Cu) and zinc (Zn), in proportions which can be varied to achieve different mechanical, electrical, and chemical properties. It is a substitutional alloy: atoms of the two constituents may replace each other with ...

or other alloys. Furthermore, many countries continue to make

gold coins, but these are primarily meant for collectors and investment purposes and are not meant for circulation.

Large gold coins

In 2007, the

Royal Canadian Mint }) is the mint of Canada and a Crown corporation, operating under the ''Royal Canadian Mint Act''. The shares of the Mint are held in trust for the Crown in right of Canada. The Mint produces all of Canada's circulation coins, and manufactures ...

produced a gold coin with a face value of $1,000,000, though the gold content was worth over $2 million at the time. It measures in diameter and is thick. It was intended as a one-off to promote a new line of

Canadian Gold Maple Leaf The Canadian Gold Maple Leaf (GML) is a gold bullion coin that is issued annually by the Government of Canada. It is produced by the Royal Canadian Mint. The Gold Maple Leaf is legal tender with a face value of 50 Canadian dollars. The market ...

coins, but after several interested buyers came forward the mint announced it would manufacture them as ordered and sell them for between $2.5 million and $3 million. As of May 3, 2007, there were five orders. One of these coins was stolen when it was on exhibition at the

Bode Museum The Bode-Museum (English: ''Bode Museum''), formerly called the Kaiser-Friedrich-Museum (''Emperor Frederick Museum''), is a listed building on the Museum Island in the historic centre of Berlin. It was built from 1898 to 1904 by order of Germa ...

in Berlin. Austria had previously produced a diameter 31 kg Philharmonic gold coin with a face value of €100,000. In 2012 the

produced the world first gold coin with a 0.11–0.14 ct diamond. The Queen's Diamond Jubilee coin has been crafted in 99.999% pure gold with a face value of $300. The largest legal tender gold coin ever produced was unveiled in 2012 by the

Perth Mint The Perth Mint is Australia's official bullion mint and wholly owned by the Government of Western Australia. Established on 20 June 1899, two years before Australia's Federation in 1901, the Perth Mint was the last of three Australian colonia ...

in Western Australia. Known as the "1 Tonne Gold Kangaroo Coin" and with a face value of one million dollars, it contains one

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

of 9999 pure gold, and is approximately 80 cm in diameter by 12 cm thick.

Collecting

Many factors determine the value of a gold coin, such as its rarity, age, condition and the number originally minted. Most gold coins minted since the late 19th century are worth slightly more than spot price, but many are worth significantly more. Gold coins coveted by collectors include the

Aureus The ''aureus'' ( ''aurei'', 'golden', used as a noun) was a gold coin of ancient Rome originally valued at 25 pure silver ''denarii'' (sin. denarius). The ''aureus'' was regularly issued from the 1st century BC to the beginning of the 4th cent ...

Solidus Solidus (Latin for "solid") may refer to: * Solidus (coin), a Roman coin of nearly solid gold * Solidus (punctuation), or slash, a punctuation mark * Solidus (chemistry), the line on a phase diagram below which a substance is completely solid * S ...

and

Spur Ryal The Spur Royal was an extremely rare England, English gold coin issued in the reign of King James I of England, James I. The coin is a development of the earlier Rose Ryal, Rose Noble, or Ryal which was worth ten shillings when issued by Kings Ed ...

. In July 2002, a very rare $20

1933 Double Eagle The 1933 double eagle is a United States 20-dollar gold coin. Although 445,500 specimens of this Saint-Gaudens double eagle were minted in 1933, none were ever officially circulated, and all but two were ordered to be melted down. However, 20 m ...

gold coin sold for a record $7,590,020 at

Sotheby's Sotheby's () is a British-founded American multinational corporation with headquarters in New York City. It is one of the world's largest brokers of fine and decorative art, jewellery, and collectibles. It has 80 locations in 40 countries, and ...

, making it by far the most valuable coin ever sold up to that time (a 1794 Flowing Hair Dollar sold for over $10 million in January 2013). In early 1933, more than 445,000 Double Eagle coins were struck by the

U.S. Mint The United States Mint is a bureau of the Department of the Treasury responsible for producing coinage for the United States to conduct its trade and commerce, as well as controlling the movement of bullion. It does not produce paper money; that ...

, but most of these were surrendered and melted down following

. Only a few coins survived. On October 4, 2007, David Albanese (president of Albanese Rare Coins) stated that a $10, 1804-dated eagle coin (made for President

Andrew Jackson Andrew Jackson (March 15, 1767 – June 8, 1845) was an American lawyer, planter, general, and statesman who served as the seventh president of the United States from 1829 to 1837. Before being elected to the presidency, he gained fame as ...

as a diplomatic gift) was sold to an anonymous private collector for $5 million. Image:Fr 1617-Schlegel 19var.jpg, Gold Guilder Image:500 reais ouro D. Sebastião.JPG, Portuguese Gold Coin, sixteenth century. Image:1933 double eagle.JPG, United States

Double Eagle A double eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz (30.0926 grams) was worth $20 at the 1849 official price of $20.67/oz.) The coins are 34 mm x 2 mm and are made from ...

. Image:Keicho_gold_coinage_Oban_Koban_Ichibuban_1601_1695.jpg,

Tokugawa coinage Tokugawa coinage was a unitary and independent metallic monetary system established by ''shōgun'' Tokugawa Ieyasu in 1601 in Japan, and which lasted throughout the Tokugawa period until its end in 1867. History The establishment of Tokugawa coi ...

Bullion coins

Precious metals in bulk form are known as bullion, and are traded on commodity markets. While obsolete gold coins are primarily collected for their

numismatic Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects. Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also includ ...

value, gold bullion coins today derive their value from the metal (gold) content, and, as such, are viewed by some investors as a "

hedge A hedge or hedgerow is a line of closely spaced shrubs and sometimes trees, planted and trained to form a barrier or to mark the boundary of an area, such as between neighbouring properties. Hedges that are used to separate a road from adjoini ...

" against inflation or a

store of value A store of value is any commodity or asset that would normally retain purchasing power into the future and is the function of the asset that can be saved, retrieved and exchanged at a later time, and be predictably useful when retrieved. The most ...

. Many nations mint

s. According to British HM Revenue & Customs investment coins are generally coins that have been minted after 1800, have a purity of not less than 900 thousandths, or have been legal tender in its country of origin. Although nominally issued as

, these coins' face value as currency is far below that of their value as bullion. The

European Commission The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body o ...

publishes annually a list of gold coins which must be treated as investment gold coins in all EU Member States. The list has legal force and supplements the law. In the United Kingdom,

HM Revenue and Customs HM Revenue and Customs (His Majesty's Revenue and Customs, or HMRC) is a non-ministerial government department, non-ministerial Departments of the United Kingdom Government, department of the His Majesty's Government, UK Government responsible fo ...

have added an additional list of gold coins alongside the European Commission list. These are gold coins that HM Revenue & Customs recognise as falling within the exemption for investment gold coins. This second list does not have legal force. South Africa introduced the

in 1967 to cater to this market; this was the reason for its convenient and memorable gold content – exactly one

troy ounce Troy weight is a system of units of mass that originated in 15th-century England, and is primarily used in the precious metals industry. The troy weight units are the grain, the pennyweight (24 grains), the troy ounce (20 pennyweights), and the ...

. It was the first modern, low-premium (i.e. priced only slightly above the

value of the gold) gold

. Bullion coins are also produced in fractions of an ounce – typically half ounce, quarter ounce, and one-tenth ounce. Bullion coins sometimes carry a nominal

face value The face value, sometimes called nominal value, is the value of a coin, bond, stamp or paper money as printed on the coin, stamp or bill itself by the issuing authority. The face value of coins, stamps, or bill is usually its legal value. Howe ...

, which is minted on the coin. However, their real value is measured as dictated by their

troy weight Troy weight is a system of Physical unit, units of mass that originated in 15th-century England, and is primarily used in the precious metals industry. The troy weight units are the Grain (unit), grain, the pennyweight (24 grains), the troy oun ...

, the current market price of the

precious metal Precious metals are rare, naturally occurring metallic chemical elements of high economic value. Chemically, the precious metals tend to be less reactive than most elements (see noble metal). They are usually ductile and have a high lustre. ...

contained, and the prevailing premium that market wishes to pay for those particular bullion coins. The face value is always significantly less than the bullion value of the coin. Legal tender bullion coins are a separate entity to bullion gold. One enjoys legal tender status, the latter is merely a raw commodity. Gold has an international currency code of XAU under

ISO 4217 ISO 4217 is a standard published by the International Organization for Standardization (ISO) that defines alpha codes and numeric codes for the representation of currencies and provides information about the relationships between individual cu ...

. ISO 4217 includes codes not only for currencies, but also for precious metals (gold, silver,

palladium Palladium is a chemical element with the symbol Pd and atomic number 46. It is a rare and lustrous silvery-white metal discovered in 1803 by the English chemist William Hyde Wollaston. He named it after the asteroid Pallas, which was itself na ...

and

platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Platinu ...

; by definition expressed per one

. Gold bullion coins usually come in 1oz, 1/2oz, 1/4oz, 1/10oz, and 1/20oz sizes. Most countries have one design that remains constant each year; others (such as the Chinese Panda coins) have variations each year, and in most cases each coin is dated. A 1/10oz bullion coin is about the same size as a U.S. dime. A 1oz gold bullion coin is about the size of a U.S. half dollar. Image:Goldeagle.jpg,

Fineness

Circulating gold coins were usually made of an alloy as other metals are mixed into the coin to make it more durable. Fineness is the actual gold content in a coin or bar and expressed as a "per mil", or thousandths. For example, a gold ingot or coin identified as being .999 fine will be 999/1000 pure gold, with the other 1/1000 being impurities.

Crown gold Crown gold is a 22 karat (kt) gold alloy used in the crown coin introduced in England in 1526 (by Henry VIII). In this alloy, the proportion of gold is 22 parts out of 24 (91.667% gold)—and is appreciably less prone to wear than the softer 23 kt ...

is the name given to .9167 (or 22-

) fine gold used in

sovereign ''Sovereign'' is a title which can be applied to the highest leader in various categories. The word is borrowed from Old French , which is ultimately derived from the Latin , meaning 'above'. The roles of a sovereign vary from monarch, ruler or ...

s and

s. Meanwhile, the United States have historically struck gold coins with .900 fine gold. Most

s are minted from .999 or finer gold.

Counterfeits

For most of history, coins were valued based on the precious metal they contain. Whether a coin was actually made by the party as claimed was of secondary importance compared to whether it contains the correct amount of metal – that is, correct weight and fineness (purity). Genuine appearance was simply a convenient shortcut to avoid time-consuming tests in everyday transactions. Gold is denser than almost all other metals, hence hard to fake. A determination of weight and volume is in many cases sufficient to spot forgeries. A coin that is not gold or below the expected fineness will either have the right size but will have a lower than expected weight or it weighs right and will be somewhat larger. Most metals that are of similar or higher density than gold are similarly or more expensive, and were unknown in ancient times (notably the

platinum group The platinum-group metals (abbreviated as the PGMs; alternatively, the platinoids, platinides, platidises, platinum group, platinum metals, platinum family or platinum-group elements (PGEs)) are six noble, precious metallic elements clustered to ...

). During the 19th century platinum was cheaper than gold and was used for counterfeiting gold coins. These coins could be detected by acoustic properties. Only two relatively inexpensive substances are of similar density to gold:

depleted uranium Depleted uranium (DU; also referred to in the past as Q-metal, depletalloy or D-38) is uranium with a lower content of the fissile isotope than natural uranium.: "Depleted uranium possesses only 60% of the radioactivity of natural uranium, hav ...

and

tungsten Tungsten, or wolfram, is a chemical element with the symbol W and atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolat ...

. Depleted uranium is government-regulated, but tungsten is more commonly available and suited for counterfeiting. Alloying gold with tungsten would not work for several reasons, but tungsten plated with a thin layer of gold is a common type of forgery. Bullion coin counterfeits (of all types) used to be rare and fairly easy to detect when comparing their weights, colors and sizes to authentic pieces. This is because the cost of reproducing any given coin precisely can exceed the market value of the originals. However, since about 2015 counterfeit coins are "flooding the market at an astonishing rate" and "it's gotten to the point where even people who deal with coins all the time may not be able to recognize a counterfeit coin right away" (

American Numismatic Association The American Numismatic Association (ANA) is an organization founded in 1891 by George Francis Heath. Located in Colorado Springs, Colorado, it was formed to advance the knowledge of numismatics (the study of coins) along educational, histori ...

(ANA), 2016).Herb Weisbaum 2016. Glitters, but Not Gold: Fake Gold and Silver Coins "Flooding" Market. nbcnews June 13, 2016, https://www.nbcnews.com/business/business-news/glitters-not-gold-fake-gold-silver-coins-flooding-market-n591201 The coins consist mostly of tungsten plated thinly with gold, have the correct weight, correct or near-correct dimensions and are professionally produced in China. The weight and dimensions of a coin of .999 fineness such as the

Maple Leaf The maple leaf is the characteristic leaf of the maple tree. It is the most widely recognized national symbol of Canada. History of use in Canada By the early 1700s, the maple leaf had been adopted as an emblem by the French Canadians along the ...

cannot be replicated precisely by a gold plated tungsten core, since tungsten has only 99.74% of the

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), wa ...

of gold. However, forgeries of alloyed gold coins (such as

made from a

crown gold Crown gold is a 22 karat (kt) gold alloy used in the crown coin introduced in England in 1526 (by Henry VIII). In this alloy, the proportion of gold is 22 parts out of 24 (91.667% gold)—and is appreciably less prone to wear than the softer 23 kt ...

alloy with 22 karats = .917 fineness) may have the correct weight and dimensions because of the lesser density of the alloy. Such forgeries can be detected testing the acoustic, electric resistance or magnetic properties. The latter method uses the fact that gold is weakly

diamagnetic Diamagnetic materials are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted ...

and tungsten is weakly

paramagnetic Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, d ...

. The effect is weak so that testing requires strong

neodymium magnet A hard_disk_drive.html"_;"title="Nickel-plated_neodymium_magnet_on_a_bracket_from_a_hard_disk_drive">Nickel-plated_neodymium_magnet_on_a_bracket_from_a_hard_disk_drive_ file:Nd-magnet.jpg.html" ;"title="hard_disk_drive_.html" ;"title="hard_disk_d ...

s and sensitive conditions (e.g., a gold coin hanging from 2 m long pendulum or placed on styrofoam floating on water), such tests can be performed without special equipment. Forgeries using gold plated tungsten are also used in counterfeiting of gold bars.

Pirates Biting gold

The rationale for biting a coin was the supposed widespread dissemination of gold plated lead coins in the 19th century. Since lead is much softer than gold, biting the coins is a sensible test for counterfeiting. While fine gold is softer than alloyed gold, and galvanized lead is softer, biting coins can only detect the crudest of forgeries. And all "gold" coins minted for circulation in the UK and America since the

Tudor period The Tudor period occurred between 1485 and 1603 in History of England, England and Wales and includes the Elizabethan period during the reign of Elizabeth I until 1603. The Tudor period coincides with the dynasty of the House of Tudor in Englan ...

(1485–1603) contained copper which made them more durable and thus hard to bite. Biting a coin to determine whether it is genuine or counterfeit is a widespread cliché depicted in many films (like the 1917 '' The Immigrant''), books (like the 1925 ''L'Or'' by

Blaise Cendrars Frédéric-Louis Sauser (1 September 1887 – 21 January 1961), better known as Blaise Cendrars, was a Swiss-born novelist and poet who became a naturalized French citizen in 1916. He was a writer of considerable influence in the European mod ...

) and plays (like the 1938 ''Mother Courage'' which is set in the

Thirty Years' War The Thirty Years' War was one of the longest and most destructive conflicts in European history The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (80 ...

1618–1648). According to a 2017 study, the assumed widespread practice of pirates biting into a coin is almost certainly a Hollywood myth. "The origin of the tradition must therefore be older. In medieval times gold coins were made of the purest gold possible for both prestige and practical reason" "This cliché might find its origin in the crude testing method used by American prospectors during the 19th century gold rush. They bit the gold nuggets they found to be sure that they were not fool's gold" Olympic champions often pose biting their gold medals, even though the medals are no longer made of solid gold. Only at three Olympics (in 1904, 1908 and 1912) were medals made of solid gold, but were also smaller.

David Wallechinsky David Wallechinsky (born David Wallace, February 5, 1948) is an American populist historian and television commentator, the president of the International Society of Olympic Historians (ISOH) and the founder and editor-in-chief of AllGov.com and ...

commented in 2012 that "It's become an obsession with the photographers. I think they look at it as an iconic shot, as something that you can probably sell. I don't think it's something the athletes would probably do on their own."Melonyce McAfee.

CNN CNN (Cable News Network) is a multinational cable news channel headquartered in Atlanta, Georgia, U.S. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable news channel, and presently owned by the M ...

, August 10, 2012.

Numismatic fake samples

There are well made

gold coins in circulation. For example, the

St. Gaudens Double Eagle The Saint-Gaudens double eagle is a twenty-dollar gold coin, or double eagle, produced by the United States Mint from 1907 to 1933. The coin is named after its designer, the sculptor Augustus Saint-Gaudens, who designed the obverse and reverse. I ...

omega counterfeit is infamous for its complexity and has fooled many

numismatics Numismatics is the study or collection of currency, including coins, tokens, paper money, medals and related objects. Specialists, known as numismatists, are often characterized as students or collectors of coins, but the discipline also includ ...

experts. Another example is the US $20 gold coin ("

double eagle A double eagle is a gold coin of the United States with a denomination of $20. (Its gold content of 0.9675 troy oz (30.0926 grams) was worth $20 at the 1849 official price of $20.67/oz.) The coins are 34 mm x 2 mm and are made from ...

"), which has raised lettering around its rim. If the coin is uncirculated, the letters will be flat on top. If slightly rounded, and the coin is uncirculated, it is a counterfeit. There are other counterfeit double eagles in which the gold and copper alloy was not thoroughly mixed. These counterfeits will have a slightly mottled appearance.

References

External links

US Mint: American Eagle Bullion Coins
at the website of the

United States Mint The United States Mint is a bureau of the Department of the Treasury responsible for producing coinage for the United States to conduct its trade and commerce, as well as controlling the movement of bullion. It does not produce paper money; tha ...

US Department of the Treasury The Department of the Treasury (USDT) is the national treasury and finance department of the federal government of the United States, where it serves as an executive department. The department oversees the Bureau of Engraving and Printing and ...

The Royal Mint: UK bullion coins
at the website of The Royal Mint {{DEFAULTSORT:Gold Coin Bullion coins

Coins A coin is a small, flat (usually depending on the country or value), round piece of metal or plastic used primarily as a medium of exchange or legal tender. They are standardized in weight, and produced in large quantities at a mint in order to ...