'Gold' (
IPA: ) is a
chemical element with the symbol 'Au' (from the
Latin ''aurum'') and
atomic number 79. It is a highly sought-after
precious metal which, for many centuries, has been used as
money, a
store of value and in
jewelery. The metal occurs as
nuggets or grains in rocks, underground "veins" and in
alluvial deposits. It is one of the
coinage metals. Gold is dense, soft, shiny and the most
malleable and
ductile of the known metals. Pure gold has an attractive bright yellow color.
Gold forms the basis for a
monetary standard used by the
International Monetary Fund (IMF) and the
Bank for International Settlements (BIS). The
ISO currency code of gold
bullion is 'XAU'. Modern industrial uses include
dentistry and
electronics, where gold has traditionally found use because of its good resistance to oxidative corrosion.
Chemically, gold is a trivalent and univalent
transition metal. Gold does not react with most chemicals, but is attacked by
chlorine,
fluorine,
aqua regia and
cyanide. Gold dissolves in
mercury, forming
amalgam alloys, but does not react with it. Gold is insoluble in
nitric acid, which will dissolve silver and base metals, and this is the basis of the gold refining technique known as "inquartation and parting". Nitric acid has long been used to confirm the presence of gold in items, and this is the origin of the colloquial term "acid test," referring to a ''gold standard'' test for genuine value.
Characteristics
Gold is the most
malleable and
ductile metal; a single
gram can be beaten into a sheet of one
square meter, or an
ounce into 300
square feet. Gold leaf can be beaten thin enough to become translucent. The transmitted light appears greenish blue, because gold strongly reflects yellow and red. Gold readily forms alloys with many other metals. These alloys can be produced to increase the hardness or to create exotic colors (see below). Native gold contains usually eight to ten percent
silver, but often much more — alloys with a silver content over 20% are called
electrum. As the amount of silver increases, the color becomes whiter and the
specific gravity becomes lower.
Gold is a good conductor of
heat and
electricity, and is not affected by
air and most
reagents. Heat, moisture,
oxygen, and most
corrosive agents have very little chemical effect on gold, making it well-suited for use in
coins and
jewelry; conversely,
halogens will chemically alter gold, and
aqua regia dissolves it via formation of the chloraurate ion.
Common
oxidation states 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 out as gold metal by adding any other metal as the reducing agent. The added metal is
oxidized and dissolves allowing the gold to be displaced from solution and be recovered as a solid precipitate.
Recent research undertaken by Sir Frank Reith of the Australian National University shows that microbes play an important role in forming gold deposits, transporting and precipitating gold to form grains and nuggets that collect in alluvial deposits.
[1]
High quality pure metallic gold is tasteless, in keeping with its resistance to corrosion (it is metal ions which confer taste to metals).
In addition, gold is very dense, a cubic meter weighing 19300
kg. By comparison, the density of
lead is 11340 kg/m³, and the densest element,
Iridium, is 22650 kg/m³.
Toxicity
Generally gold is not harmful if consumed and is sometimes used as a food decoration in the form of
gold leaf. However, consumption and accumulation of large amounts of gold (or
gold compounds) in the body can still be toxic and the symptoms are similar to those of
heavy metal poisoning.
Applications
As the metal
''Medium of monetary exchange.'' In various countries, gold is used as a standard for
monetary exchange, in
coinage and in
jewelry. Pure gold is too soft for ordinary use and is typically hardened by alloying with copper or other base metals. The gold content of gold alloys is measured in
carats (k), pure gold being designated as 24k.
Gold coins intended for circulation from 1526 into the 1930s were typically a standard 22k alloy called
crown gold, for hardness. Modern collector/investment
bullion coins (which do not require good mechanical wear properties) are typically 24k, although the
American Gold Eagle and British
gold sovereign continue to be made at 22k, on historical tradition. The
Canadian Gold Maple Leaf coin contains the highest purity gold of any popular bullion coin, at 99.999% (.99999 fine). Several other 99.99% pure gold coins are currently available, including Australia's Gold Kangaroos (first appearing in 1986 as the
Australian Gold Nugget, with the kangaroo theme appearing in 1989), the several coins of the Australian Lunar Calendar series, and the Austrian Philharmonic. In 2006, the U.S. Mint began production of the
American Buffalo gold bullion coin also at 99.99% purity.
Today, gold has fallen out of use in coins made for general circulation.
''Jewellery.'' Because of the softness of pure (24k) gold, it is usually alloyed with base metals for use in jewellery, altering its hardness and ductility, melting point, color and other properties. Alloys with lower "k", typically 22k, 18k, 14k or 10k, contain higher percentages of copper, silver or other base metals in the alloy.
Copper is the most commonly used base metal, yielding a redder metal. Eighteen carat gold containing 25% copper is found in antique and Russian jewelry and has a distinct, though not dominant, copper cast, creating an attractively warm color (
rose gold). Fourteen carat gold-copper alloy is nearly identical in color to certain
bronze alloys, and both may be used to produce police and other badges. Blue gold can be made by alloying with
iron and purple gold can be made by alloying with
aluminum, although rarely done except in specialized jewelry. Fourteen and eighteen carat gold alloys with
silver alone appear greenish-yellow and are referred to as green gold. White gold alloys can be made with
palladium or
nickel. White 18 carat gold containing 17.3% nickel, 5.5% zinc and 2.2% copper is silver in appearance. Nickel is toxic, however, and its release from nickel white gold is controlled by legislation in Europe. Alternative white gold alloys are available based on palladium, silver and other white metals (World Gold Council), but the palladium alloys are more expensive than those using nickel. High-carat white gold alloys are far more resistant to corrosion than are either pure
silver or
sterling silver. The Japanese craft of
Mokume-gane exploits the colour contrasts between laminated colored gold alloys to produce decorative wood-grain effects.
The 220 kg Gold brick displayed in Chinkuashi Gold Museum, Taiwan.
Other uses:
★ In medieval times, gold was often seen as beneficial for the health, in the belief that something that rare and beautiful could not be anything but healthy. Even some modern
esotericists and forms of
alternative medicine assign metallic gold a healing power. Some gold salts do have anti-inflammatory properties and are used as pharmaceuticals in the treatment of arthritis and other similar conditions. However, only salts and radioisotopes of gold are of pharmacological value, as elemental (metallic) gold is inert to all chemicals it encounters inside the body.
★ Gold leaf, flake or dust is used on and in some gourmet foodstuffs, notably sweets and drinks as decorative ingredient.
[2] Gold flake was used by the nobility in Medieval
Europe as a decoration in foodstuffs and drinks, in the form of leafs, flakes or dust, either to demonstrate the host's wealth or in the honest belief that something that valuable and rare must be beneficial for one's health.
★ Gold
solder is used for joining the components of gold jewellery by high-temperature hard soldering or
brazing. If the work is to be of
hallmarking quality, gold solder must match the carat weight of the work, and alloy formulae are manufactured in most industry-standard carat weights 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 be used in food and has the
E Number 175.
Goldwasser (
German: "Goldwater") is a traditional herbal
liqueur produced in
Gdańsk,
Poland and
Schwabach,
Germany and contains flakes of gold leaf. There are also some expensive (~$1000) cocktails which contain flakes of gold leaf. However, since metallic gold is inert to all body chemistry, it adds no taste nor has it any other nutritional effect and leaves the body unaltered.
★ ''Dentistry.'' 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.
★ Gold can be made into
thread and used in
embroidery.
★ Gold is
ductile and
malleable, meaning it can be drawn into very thin wire and can be beaten into very thin sheets known as gold leaf.
★ Gold produces a deep, intense red color when used as a coloring agent in glass.
★ In photography, Gold toners are used to shift the color of silver bromide black and white prints towards brown or blue tones, or to increase their stability. Used on sepia-toned prints, gold toners produce red tones. Kodak publish formulae for several types of gold toners, which use gold as the chloride (Kodak, 2006).
★ ''Electronics.'' The concentration of free electrons in gold metal is 5.90×10
22 cm
-3. Gold is highly conductive to electricity, and has been used for electrical wiring in some high energy applications (silver is even 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.
★
★ 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 electrical connectors of all kinds, 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, is highly 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
computers, communications equipment,
spacecraft,
jet aircraft engines) remains very common, and is unlikely to be replaced in the near future by any other metal.
★
★ Besides sliding electrical contacts, gold is also used in
electrical contacts because of its resistance to
corrosion,
electrical conductivity,
ductility and lack of
toxicity.
[3] Switch contacts are generally subjected to more intense corrosion stress than are sliding contacts.
★
Colloidal gold (Colloidal sols of gold
nanoparticles) in water are intensely red-
colored, and can be made with tightly-controlled particle sizes up to a few tens of nm 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 (Faulk and Taylor 1979). In ultrathin sections of tissues viewed by electron microscopy, the immunogold labels appear as extremely dense round spots at the position of the
antigen (Roth et al. 1980). Colloidal gold is also the form of gold used as gold paint on
ceramics prior to firing.
★ 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 electrical charge to earth, and its very high density provides stopping power for electrons in the SEM's
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.
★ Many competitions, and honors, such as the
Olympics and the
Nobel Prize, award a gold
medal to the winner.
★ As gold is a good reflector of both infrared and visible light, it is used for the protective coatings on many artificial
satellites and in infrared protective faceplates in thermal protection suits and astronauts' helmets.
★ Gold is used as the reflective layer on some
high-end CDs.
★ The isotope gold-198, (
half-life: 2.7 days) is used in some
cancer treatments and for treating other diseases.
★ Automobiles may use gold for heat insulation.
McLaren F1 uses gold foil in the engine compartment.
[4]
As gold chemical compounds
Gold is attacked by and dissolves in alkaline solutions of potassium or sodium
cyanide, and gold cyanide is the
electrolyte used in commercial
electroplating of gold onto base metals and
electroforming. Gold chloride (chloroauric acid) solutions are used to make colloidal gold by reduction with
citrate or
ascorbate ions. Gold chloride and gold oxide are used to make highly-valued cranberry or red-colored glass, which, like
colloidal gold sols, contains evenly-sized spherical gold
nanoparticles.
History
Gold has been known and highly valued since
prehistoric times. It may have been the first metal used by
humans and was valued for ornamentation and rituals.
Egyptian hieroglyphs from as early as 2600 BC describe gold, which king
Tushratta of the
Mitanni claimed was "more plentiful than dirt" in Egypt.
[5] Egypt and
Nubia had the resources to make them major gold-producing areas for much of history. Gold is also mentioned several times in the
Old Testament, and is included with the gifts of the
magi in the first chapters of Matthew
New Testament The south-east corner of the
Black Sea was famed for its gold. Exploitation 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 between
643 and 630 BC.
The
Mali Empire in Africa was famed throughout the old world for its large amounts of gold.
Mansa Musa, ruler of the empire (1312–1337) became famous throughout the old world for his great
hajj to
Mecca in 1324. On the way to Mecca, when he passed through
Cairo in July of 1324, he was reportedly accompanied by a
caravan that included thousands of people and nearly a hundred camels, giving away so much gold that it took over a decade for the economy across North Africa to recover, due to the rapid inflation that it initiated.
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
Central America,
Peru, and
Colombia.
Although the price of some platinum group metals can be much higher, gold has long been considered the most desirable of
precious metals, and its value has been used as the standard for many
currencies (known as the
gold standard) in history. 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 made fun of 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.
There is an age-old tradition of biting gold in order to test its authenticity. Although this is certainly not a professional way of examining gold, the ''bite test'' should score the gold because gold is considered a soft metal according to the
Mohs' scale of mineral hardness. The purer the gold the easier it should be to mark it. Painted lead can cheat this test because lead is softer than gold (and may invite a small risk of
lead poisoning if sufficient lead is absorbed by the biting).
This 156 ounce nugget was found by an individual prospector in the Southern California Desert using a metal detector.
Gold in antiquity was relatively easy to obtain
geologically; however, 75% of all gold ever produced has been extracted since 1910.
[6] It has been estimated that all the gold in the world that has ever been refined would form a single cube 20 m (66 ft) on a side (equivalent to 8000 m³).
The primary goal of the
alchemists was to produce gold from other substances, such as
lead — presumably by the interaction with a mythical substance called the
philosopher's stone. Although they never succeeded in this attempt, the alchemists promoted an interest in what can be done with substances, and this laid a foundation for today's
chemistry. Their symbol for gold was the
circle with a point at its center (☉), which was also the
astrological symbol, the
Egyptian
hieroglyph and the ancient
Chinese character for the
Sun. For modern attempts to produce artificial gold, see
gold synthesis.
During the 19th century,
gold rushes occurred whenever large gold deposits were discovered. The first major gold strike in the United States occurred in a small north Georgia town called Dahlonega.
[7] Further gold rushes occurred in
California,
Colorado,
Otago,
Australia,
Witwatersrand,
Black Hills, and
Klondike.
Because of its historically high value, much of the gold mined throughout history is still in circulation in one form or another.
Production
Gold Nuggets found in Arizona
,
Gold mining,
Gold extraction
The entrance to an underground gold mine in Victoria, Australia
Gold ore
World gold production trend
2.PNG)
Gold output in 2005
Economic
gold extraction can be achieved from ore grades as little as 0.5 g/1000 kg (0.5 parts per million, ppm) on average in large easily mined deposits. Typical ore grades in
open-pit mines are 1–5 g/1000 kg (1–5 ppm), ore grades in underground or
hard rock mines are usually at least 3 g/1000 kg (3 ppm) on average. Since ore grades of 30 g/1000 kg (30 ppm) are usually needed before gold is visible to the naked eye, in most gold mines the gold is invisible.
Since the 1880s,
South Africa has been the source for a large proportion of the world’s gold supply, with about 50% of all gold ever produce having come from South Africa. Production in 1970 accounted for 79% of the world supply, producing about 1,000
tonnes. However by 2005 production was just 294 tonnes according to the
British Geological Survey. This sharp decline was due to the increasing difficulty of extraction and changing economic factors affecting the industry in South Africa.
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 gold deposits the world has ever seen. Gold fields located within the basin in the
Free State and
Gauteng provinces are extensive in strike and dip requiring some of the world's deepest mines, with the Savuka and
TauTona mines being currently the world's deepest gold mine at 3,777 m. The
Second Boer War of 1899–1901 between the
British Empire and the
Afrikaner Boers was at least partly over the rights of miners and possession of the gold wealth in South Africa.
Other major producers are
United States,
Australia,
China,
Russia and
Peru. Mines in
South Dakota and
Nevada supply two-thirds of gold used in the United States. 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. Today about one-quarter of the world gold output is estimated to originate from artisanal or small scale mining.
[8]
After initial production, gold is often subsequently refined industrially by the
Wohlwill process or the
Miller process. Other methods of assaying and purifying smaller amounts of gold include
parting and inquartation as well as
cuppelation, or refining methods based on the dissolution of gold in
aqua regia.
The world's oceans hold a vast amount of gold, but in very low concentrations (perhaps 1–2 parts per 10 billion). A number of people have claimed to be able to economically recover gold from sea water, but so far they have all been either mistaken or crooks. Reverend Prescott Jernegan ran a gold-from seawater swindle in America in the 1890s. A British fraud ran the same scam in England in the early 1900s.
[9]
Fritz Haber (the German inventor of the
Haber process) attempted commercial extraction of gold from sea water in an effort to help pay Germany's reparations following the
First World War. Unfortunately, his assessment of the concentration of gold in sea water was unduly high, probably due to sample contamination. The effort produced little gold and cost the German government far more than the commercial value of the gold recovered. No commercially viable mechanism for performing gold extraction from sea water has yet been identified.
Gold synthesis is not economically viable and is unlikely to become so in the foreseeable future.
The average gold mining and extraction costs are $238 per
troy ounce but these can vary widely depending on mining type and ore quality. In 2001, global mine production amounted to 2,604 tonnes, or 67% of total gold demand in that year. At the end of 2001, it was estimated that all the gold ever mined totalled 145,000 tonnes.
[10]
Price
Main articles: Gold as an investment,
Gold standard
Like other precious metals, gold is measured by
troy weight and by
grams. When it is alloyed with other metals the term ''
carat'' or ''karat'' is used to indicate the amount of gold present, with 24 karats being pure gold and lower ratings proportionally less. The purity of a
gold bar can also be expressed as a decimal figure ranging from 0 to 1, known as the
millesimal fineness, such as 0.995 being very pure.
The price of gold is determined on the open market, but a procedure known as the
Gold Fixing in
London, originating in September 1919, provides a daily benchmark figure to the industry. The afternoon fixing appeared in 1968 to fix a price when US markets are open.
The high price of gold is due to its rare amount. Only three parts out of every billion (0.000000003) in the Earth's crust is gold.
Gold price per ounce in USD since 1968, in actual US$ and 2006 US$
Historically gold was used to back currency; in an economic system known as the
gold standard, a certain
weight of gold was given the name of a unit of currency. For a long period, the United States government set the value of the US dollar so that one
troy ounce was equal to $20.67 ($664.56/kg), but in 1934 the dollar was revalued to $35.00 per troy ounce ($1125.27/kg). By 1961 it was becoming hard to maintain this price, and a pool of US and European banks agreed to manipulate the market to prevent further currency devaluation against increased gold demand.
On
17 March 1968, economic circumstances caused the collapse of the gold pool, and a two-tiered pricing scheme was established whereby gold was still used to settle international accounts at the old $35.00 per troy ounce ($1.13/g) but the price of gold on the private market was allowed to fluctuate; this two-tiered pricing system was abandoned in 1975 when the price of gold was left to find its free-market level. Central banks still hold historical
gold reserves as a
store of value although the level has generally been declining. 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 ever mined, as does the similarly-laden
U.S. Bullion Depository at
Fort Knox.
Since 1968 the price of gold on the open market has ranged widely, with a record high of $850/oz ($27,300/kg) on
21 January 1980, to a low of $252.90/oz ($8,131/kg) on
21 June 1999 (London Fixing).
[11] On
11 May 2006 the London gold fixing was $715.50/oz ($23,006/kg).
[12]
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.
[13]
Compounds
Although gold is a
noble metal, it forms many and diverse compounds. The
oxidation state of gold in its compound ranges from -1 to 5+ but Au(I) and Au(III) dominate. Gold(I), referred to as the aurous ion, is the most common oxidation state with “soft”
ligands such as
thioethers,
thiolates, and tertiary
phosphines. Au(I) compounds are typically linear. A good example is Au(CN)
2–, which is the soluble form of gold encountered in mining. Curiously, aurous complexes of water are rare. The binary
gold halides, such as AuCl, form zig-zag polymeric chains, again featuring linear coordination at Au. Most drugs based on gold are Au(I) derivatives.
[14]
Gold(III) (“auric”) is a common oxidation state and is illustrated by
gold(III) chloride, Au
Cl3. Its derivative is chloroauric acid, HAuCl
4, which forms when Au dissolves in
aqua regia. Au(III) complexes, like other d
8 compounds, are typically
square planar.
Less common oxidation states: Au(-I), Au(II), and Au(V)
Compounds containing the Au
- anion are called aurides.
Caesium auride, CsAu which crystallizes in the
caesium chloride motif. Other aurides include those of
Rb+,
K+, and tetramethylammonium (CH
3)
4N
+.
[Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.] Gold(II) compounds are usually
diamagnetic with Au-Au bonds such as [Au(CH
2)
2P(C
6H
5)
2]
2Cl
2. A noteworthy, legitimate Au(II) complex contains
xenon as a ligand, [AuXe
4](Sb
2F
11)
2.
[15] Gold pentafluoride is the sole example of Au(V), the highest verified oxidation state.
[16]
Some gold compounds exhibit ''
aurophilic bonding'', which describes the tendency of gold ions to interact at distances that are too long to be a conventional Au-Au bond but shorter that van der Waals bonding. The interaction is estimated to be comparable in strength to that of a
hydrogen bond.
Mixed valence compounds
Well-defined cluster compounds are numerous.
[ In such cases, gold has a fractional oxidation state. A representative example is the octahedral species {Au(P(C6H5)3)}62+. Gold chalcogenides, e.g. "AuS" feature equal amounts of Au(I) and Au(III).]
Isotopes
Main articles: isotopes of gold
There is one stable isotope of gold, and 18 radioisotopes with 195Au being the most stable with a half-life of 186 days.
Gold has been proposed as a "salting" material for nuclear weapons (cobalt is another, better-known salting material). A jacket of natural gold, irradiated by the intense high-energy neutron flux from an exploding thermonuclear weapon, would transmute into the radioactive isotope Au-198 with a half-life of 2.697 days and produce approximately .411 MeV of gamma radiation, significantly increasing the radioactivity of the weapon's fallout for several days. Such a weapon is not known to have ever been built, tested, or used.
Symbolism
Gold has been associated with the extremities of utmost evil and great sanctity throughout history. In the Book of Exodus, the Golden Calf is a symbol of idolatry and rebellion against God. In Communist propaganda, the golden pocket watch and its fastening golden chain were the characteristic accessories of the class enemy, the bourgeois and the industrial tycoons. Credit card companies associate their product with wealth by naming and coloring their top-of-the-range cards “gold;” although, in an attempt to out-do each other, platinum (and the even-more-elite black card) has now overtaken gold.
On the other hand 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. Eminent orators such as John Chrysostom were said to have a “mouth of gold with a silver tongue.” Gold is associated with notable anniversaries, particularly in a 50-year cycle, such as a golden wedding anniversary, golden jubilee, etc.
Great human achievements are frequently rewarded with gold, in the form of medals and decorations. Winners of races and prizes are usually awarded the gold medal (such as the Olympic Games and the Nobel Prize), while many award statues are depicted in gold (such as the Academy Awards, the Golden Globe Awards the Emmy Awards, the Palme d'Or, and the British Academy Film Awards).
Medieval kings were inaugurated under the signs of sacred oil and a golden crown, the latter symbolizing the eternal shining light of heaven and thus a Christian king's divinely inspired authority. Wedding rings are traditionally made of gold; since it is long-lasting and unaffected by the passage of time, it is considered a suitable material for everyday wear as well as a metaphor for the relationship. In Orthodox Christianity, the wedded couple is adorned with a golden crown during the ceremony, an amalgamation of symbolic rites.
The symbolic value of gold varies greatly around the world, even within geographic regions. For example, gold is quite common in Turkey but considered a most valuable gift in Sicily.
From most ancient times, gold has been connected to religion and spirituality, especially associated with the Sun. It was also seen as the best material to decorate religious imagery, all over history.
See also
★ Carat (purity)
★ Colloidal gold
★ White gold
★ Rose gold
★ Black gold
★ Gold as an investment
★ Gold coin
★ Precious metal
★ Digital gold currency
★ Hallmark
★ Altay Mountains
★ Commodity fetishism
Footnotes
1. Environment & Nature News - Bugs grow gold that looks like coral - 28/01/2004
2.
3. General Electric Contact Materials
4. Supercars.net. 1994 McLaren F1
5. Nicholas Reeves, Egypt's False Prophet: Akhenaten, Thames & Hudson, p.69
6. GOLDSHEET - YEARLY and CUMULATIVE WORLD GOLD PRODUCTION CHARTS
7. Road to adventure
8. Removal of Barriers to the Abatement of Global Mercury Pollution from Artisanal Gold Mining, , Christian, Beinhoff, ,
9. Dan Plazak, ''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)
10. World Gold Council > discover > gold knowledge > frequently asked questions
11. kitco.com: GOLD - London PM Fix 1975 - present (GIF)
12. London Gold & Silver Statistics from the LBMA
13. World Gold Council > value > research & statistics > statistics > supply and demand statistics
14. Gold-Based Medicinal Agents, Shaw III, C. F., , , Chemical Reviews, 1999
15. Xenon as a Complex Ligand: The Tetra Xenono Gold(II) Cation in AuXe42+(Sb2F11−)2, Seidel, S.; Seppelt, K., , , Science, 2000
16. Revising the Highest Oxidation States of the 5d Elements: The Case of Iridium(+VII), Riedel, S.; Kaupp, M., , , Angewandte Chemie International Edition, 2006
Bibliography
★ Faulk W, Taylor G (1979) ''An Immunocolloid Method for the Electron Microscope'' Immunochemistry '8', 1081–1083.
★ Kodak (2006) Toning black-and-white materials. Technical Data/Reference sheet G-23, May 2006.
★ Roth J, Bendayan M, Orci L (1980) ''FITC-Protein A-Gold Complex for Light and Electron Microscopic Immunocytochemistry''. Journal of Histochemistry and Cytochemistry '28', 55–57.
★ World Gold Council, Jewellery Technology, Jewellery Alloys
★ Los Alamos National Laboratory – Gold
External links
★ WebElements.com – Gold (also used as a reference)
★ ''Getting Gold'' 1898 book
★ Technical Document on Extraction and Mining of Gold
★ Impacts of Gold Mining: Earthworksaction
2.PNG)
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