How is gold formed? Also, how is gold used in coinage?

Answer 1

I
Introduction

Gold, symbol Au (from Latin aurum, “gold”), soft, dense, bright yellow metallic element. Gold is one of the transition elements of the periodic table; its atomic number is 79.
II
Properties

Pure gold is the most malleable and ductile of all the metals. It can easily be beaten or hammered to a thickness of 0.000013 cm (0.000005 in), and 29 g (1.02 oz) could be drawn into a wire 100 km (62 mi) long. It is one of the softest metals (hardness, 2.5 to 3) and is a good conductor of heat and electricity. Gold is bright yellow and has a high lustre. Finely divided gold, like other metallic powders, is black; colloidally suspended gold ranges in colour from ruby red to purple (see Colloid).

Gold is extremely inactive. It is unaffected by air, heat, moisture, and most solvents. It will, however, dissolve in aqueous mixtures containing various halogens such as chlorides, bromides, or some iodides. It will also dissolve in some oxidizing mixtures, such as cyanide ion with oxygen, and in aqua regia, a mixture of hydrochloric and nitric acids. The chlorides and cyanides are important compounds of gold. Gold melts at about 1,064° C (about 1,947° F), boils at about 2,808° C (about 5,086° F), and has a relative density of 19.3; its atomic weight is 196.967.
III
Occurrence

Gold is found in nature in quartz veins or seams, nuggets, flakes, and secondary alluvial deposits as a free metal or in a combined state. There are several chemical and physical processes that may cause these formations, and it is also likely that colonies of soil bacteria and fungi play a part in gold agglomerations. Gold is widely distributed although it is rare, being 75th in order of abundance of the elements in the crust of the Earth. It is almost always associated with varying amounts of silver; the naturally occurring gold-silver alloy is called electrum. Gold occurs, in chemical combination with tellurium, in the minerals calaverite and sylvanite along with silver, and in the mineral nagyagite along with lead, antimony, and sulphur. It occurs with mercury as gold amalgam. It is generally present to a small extent in iron pyrites; galena, the lead sulphide ore that usually contains silver, sometimes also contains appreciable amounts of gold. Gold also occurs in sea water to the extent of 5 to 250 parts by weight to 100 million parts of water. Although the quantity of gold present in sea water is more than 9 billion tonnes, the cost of recovering the gold would be far greater than the value of the gold that could thus be recovered.
IV
Uses

The metal has been known and highly valued from earliest times, not only because of its beauty and resistance to corrosion, but also because gold is easier to work than all other metals. In addition, gold was easier to obtain in pure form than the other metals. Because of its relative rarity, gold became used as currency and as a basis for international monetary transactions (Gold Standard). The unit used in weighing gold is the troy ounce; 1 troy ounce is equivalent to 31.1 grams.

The major portion of the gold produced is used in coinage and jewellery (see Metalwork). For these purposes it is alloyed with other metals to give it the necessary hardness. The gold content in alloys is expressed in carats. Coinage gold is composed of 90 parts gold to 10 parts silver. Green gold used in jewellery contains copper and silver; white gold contains zinc and nickel, or platinum metals.

Gold is also used in the form of gold leaf in the arts of gilding and lettering. Purple of Cassius, a precipitate of finely divided gold and stannic hydroxide formed by the interaction of auric chloride and stannous chloride, is used in colouring ruby glass. Chlorauric acid is used in photography for toning silver images. Potassium gold cyanide is used in electrogilding. Gold is also used in dentistry. Radioisotopes of gold are used in biological research and in the treatment of cancer (see Isotopic Tracer).

Answer 2

You mean how is gold deposited? It is disolved in the ground water and tranported by it and precipitated out. Often in infill quartz veins. For coins it is stamped just like any other metal.
How is it formed originally? In the hearts of collapsing stars just before they go super nova. All gold on earth is a part of a blown up star. yes stardust.

Answer 3

Gold is formed in the cores of huge exploding stars.

Answer 4

gold is formed in stars

Answer 5

Gold is a highly sought-after precious metal that for many centuries has been used as money, a store of value and in jewellery. The metal occurs as nuggets or grains in rocks and in alluvial deposits and is one of the coinage metals. It is a soft, shiny, yellow, dense, malleable, and ductile (trivalent and univalent) transition metal. Modern industrial uses include dentistry and electronics. Gold forms the basis for a monetary standard used by the International Monetary Fund (IMF) and the Bank for International Settlements (BIS). Its ISO currency code is XAU.

Gold is a chemical element in the periodic table with the symbol Au (from the Latin aurum) and atomic number 79. The adjective auric refers to something made of gold. Gold does not react with most chemicals but is attacked by chlorine, fluorine, aqua regia and cyanide. Gold dissolves in mercury. In particular, gold is insoluble in nitric acid, which will dissolve most other metals. Nitric acid has long been used to confirm the presence of gold in items.

Notable characteristics
Gold is a metallic element with a characteristic yellow color, but can also be black or ruby when finely divided, while colloidal solutions are intensely colored and often purple. These colors are the result of gold's plasmon frequency lying in the visible range, which causes red and yellow light to be reflected, and blue light to be absorbed. Only silver colloids exhibit the same interactions with light, albeit at a shorter frequency, making silver colloids yellow in color.

It is the most malleable and ductile metal known; a single gram can be beaten into a sheet of one square meter, or an ounce into 300 square feet. Gold readily forms alloys with many other metals. These alloys can be produced to increase the hardness or to create exotic colors. Adding copper yields a redder metal, iron blue, aluminium purple, platinum metals white, and natural bismuth together with silver alloys produce black. Native gold contains usually eight to ten per cent 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.

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 the addition of virtually 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 Frank Reith of the Australian National University shows that microbes play an important role in the formation of gold deposits, transporting and precipitating gold to form grains and nuggets that collect in alluvial deposits. [1]

The concentration of free electrons in gold metal is 5.90×1022 cm-3.

and

Gold coins are one of the oldest forms of money. The first gold coins in history were coined by the Lydian king Croesus in about 560 BC, not long after the first silver coins were minted by king Pheidon of Argos in about 700 BC.

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.

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Answer 6

it is found in mines like other metals after cleaning some impurities are added to make a coin. plz don't forget it mark as best answer tommorow