Diavik Diamond Mine

Diavik Diamond Mine
The Diavik Diamond Mine, near Bathurst Inlet, Nunavut
Coordinates: 64°29′46″N 110°16′24″W / 64.49611°N 110.27333°W / 64.49611; -110.27333
Country	Canada
Territory	Northwest Territories
Area [1]
- Total	7.0 km2 (2.7 sq mi)
Elevation [1]	416 m (1,365 ft)
Website	http://www.diavik.ca/

The Diavik Diamond Mine is a diamond mine in the North Slave Region of the Northwest Territories, Canada, about 300 kilometres (186 miles) north of Yellowknife.^[2] It has become an important part of the regional economy, employing 700, grossing C$100 million in sales, and producing 8 million carats (1600 kg) of diamonds annually. The area was surveyed in 1992 and construction began in 2001, with production commencing in January 2003. It is connected by an ice road and Diavik Airport with a 5,235-foot (1,596 m) gravel runway regularly accommodating Boeing 737 jet aircraft.

The mine is owned by a joint venture between the Harry Winston Diamond Corporation and Diavik Diamond Mines Inc., a subsidiary of Rio Tinto Group. The lifespan of the mine is expected to be 16 to 22 years.

The mine consists of three kimberlite pipes associated with the Lac de Gras kimberlite field and is located on an island 20 square kilometres (8 sq mi) in Lac de Gras and is informally called East Island. It is about 220 kilometres (137 mi) south of the Arctic Circle.

In 2006 the ice road from Yellowknife to the Diavik mine, and neighboring mines, froze late and thawed early.^[1] The Diavik mine was unable to truck in all the supplies needed for the rest of 2006 before the road closed and arrangements had to be made to bring the remainder of the supplies in by air.

On July 5, 2007 a consortium of seven mining companies, including Rio Tinto, announced they are sponsoring environmental impact studies to construct a deep-water port in Bathurst Inlet.^[3][4] Their plans include building a 211 km (131 mi) road connecting the port to their mines. The port would serve vessels of up to 25,000 tonnes.

Argyle diamond mine

Argyle diamond mine
Argyle diamond mine (Australia)
Location	Lake Argyle
State	Western Australia
Country	Australia
Owner
Company	Rio Tinto Group
Website	http://www.argylediamonds.com.au/
Production
Products	Diamonds
History
Opened	1985
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The Argyle diamond mine (16°42′44″S 128°23′51″E / 16.71222°S 128.3975°E / -16.71222; 128.3975Coordinates: 16°42′44″S 128°23′51″E / 16.71222°S 128.3975°E / -16.71222; 128.3975) is a diamond mine located in the Kimberley region of Western Australia. The Argyle mine is the largest diamond producer in the world by volume, although due to the low proportion of gem-quality diamonds, is not the leader by value. It is the only known significant source of pink diamonds, producing 90 to 95% of the world's supply.

The Argyle diamond mine is also notable for being the first successful commercial diamond mine exploiting a volcanic pipe of lamproite, rather than the more usual kimberlite pipe. Much earlier commercial attempts to mine diamonds from a lamproite pipe in Arkansas in the southern United States were unsuccessful; the lamproite pipe there is now contained within the Crater of Diamonds State Park. The Argyle mine is owned by the Rio Tinto Group, a diversified mining company which also owns the Diavik Diamond Mine in Canada and the Murowa diamond mine in Zimbabwe.

Description

A false-color NASA image of the Argyle mine. Blue colours show the location of the mine and its depressed elevation as a result of the open pit mining technique.

The mine covers about 450,000 square metres (110 acres), stretching in a mostly linear shape about 1600 metres (5,200 ft) long and 150 to 600 metres (500 to 2,000 ft) wide. The mine is of open pit construction, and reaches about 600 metres (1,900 ft) deep at its deepest point. The open cut is nearing the end of its life and is due to close in 2009.

An underground block cave mine is currently under development.

Location

The Argyle diamond mine is located in the Kimberley region in the far northeast of the Australian state of Western Australia. It is located to the southwest of Lake Argyle in the Matsu Ranges, about 550 kilometres (340 miles) southwest of Darwin. Because the mine is located about 120 kilometres (75 miles) from the nearest settlement (Kununurra), a complete residential camp has been constructed on site. Most of the 520 workers commute from Perth, over 2,000 kilometres (1,200 mi) away, for alternating two week shifts at the mine. The mine has encouraged local employment and has a large number of indigenous local people working within the mine.

Geology

The mine is the first successful commercial diamond mine (except alluvial mining operations) not located on a kimberlite pipe. The pipe is named "AK-1", although it is commonly simply called the "Argyle pipe".

The volcanic pipe is a diatreme, composed of olivine lamproite, present as tuff and lava. Peripheral volcanic facies suggest the lamproite eruption formed a maar. At the margins of the volcanic pipe the lamproite is mixed with a volcanic breccia containing shattered wall rock fragments mixed and milled by the eruption. Minerals in the marginal facies include zeolite minerals, micas, kaolinite and clays, typical of post-eruption hydrothermal circulation.

Diamonds are found within the intact core of the volcanic pipe, as well as within some of the marginal breccia facies and maar facies. However, some diamonds are considered to have been resorbed during the post-eruption cooling of the pipe and converted to graphite.

The diatreme pipe formed by explosive eruption of the lamproite magma through a zone of weakness in the continental crust.

The diamonds found at the Argyle pipe have been dated to about 1.58 billion years of age, while the volcano which created the pipe is aged between 1.1 and 1.2 billion years old. This represents a relatively short period during which diamond formation could have taken place (around 400 million years), which may explain the small average size and unusual physical characteristics of Argyle diamonds. Diamonds found in the Argyle pipe are predominantly eclogitic, meaning that the carbon is of organic origin (see Natural history of diamonds).

In addition to the pipe itself, there are a number of semi-permanent streams that have eroded away portions of the pipe and created significant alluvial deposits of diamonds. These deposits are also actively mined.

Production

The Argyle diamond mine leads the world in volume production of diamond, averaging annual production of 35 million carats (7,000 kg), or about one third of global production of natural diamonds. Production peaked in 1994, when 42 million carats (8,400 kg) were produced. Of this quantity only 5% is considered gem-quality, with the rest being either near-gem quality or industrial grade; this is somewhat below world averages of about 20% of mined diamonds qualifying as gem-grade. Since the mine's opening in 1985, it has produced over 600 million carats (120,000 kg) of diamonds.

Most of Argyle's gem quality production is in brown diamonds. These diamonds are usually difficult to sell, although Rio Tinto has seen some success in a decade-long marketing campaign to promote brown diamonds as champagne and cognac toned. In contrast, the company has no problems selling pink and red diamonds, which are very rare and in high demand, therefore commanding premium prices. The pink diamonds are processed and sold as polished diamonds by a specialised team based in Perth to customers world wide. The highlight of the coloured diamond industry calendar is the annual Pink Diamond Tender. Access to its collector's edition catalogue and website access in itself is highly sought after.

The mine has ore processing and diamond sorting facilities on site. Once diamonds are removed from the ore and acid washed, they are sorted and shipped to Perth for further sorting and sale. A significant quantity of diamonds are cut in India, where low costs of labor allow small diamonds to be cut for a profit; this is especially relevant to the Argyle mine, which on average produces smaller rough diamonds than other mines do.

Diamond characteristics

The diamonds produced at the Argyle diamond mine are of an average low quality. Only 5% of mined diamonds are of gem quality, compared to a worldwide average of 20%; of the remaining 95%, they are about evenly split between classifications of "near gem quality" and industrial grade. 80% of Argyle diamonds are brown, followed by 16% yellow, 2% white, 2% grey, and less than 1% pink and green. Despite the low production volume of pink and red diamonds, the Argyle mine is the only reliable source in the world, producing 90 to 95% of all pink and red diamonds. Most Argyle diamonds are classified as type 1a (see material properties of diamond), and have low levels of nitrogen impurities, their colour resulting instead from structural defects of the crystal lattice. Argyle diamonds tend to fluoresce blue or dull green under ultraviolet light, and blue-white under X-ray radiation. The most common inclusion is unconverted graphite, followed by crystalline inclusions of orange garnet, pyroxene, and olivine.

Reserves

Initial proven reserves of the Argyle mine were 61 million tonnes of ore, with an average ore grade of 6.8 carats (1.36 g) per or tonne, about 400 million carats (80,000 kg). Further estimated reserves of 14 million tonnes of ore, at a grade of 6.1 carats (1.22 g) per tonne (85 million carats, 17,000 kg), also existed. As of 2001, reserves and resources in the open-pit mined area contain 220 million tonnes of 2.5 to 3.0 carat (500 to 600 mg) per tonne graded ore, sufficient to sustain current production rates until 2007. The ore grades at the Argyle mine are unusually high, with most commercial diamond mines averaging grades of 0.3 to 1.0 carats (60 to 200 mg) per metric ton. Alluvial deposits of diamonds are believed to have been exhausted.

In 1995, drilling samples taken from about 300 metres below the floor of the pit indicated the possible presence of about 100 million tons of ore, with an estimated grade of 3.7 carats (740 mg) per ton. In 1998, it was decided to instead move mining operations toward the west ridge of the mine, where 64 million tons of ore graded at 2.6 carats (520 mg) per ton are located.

An exploration decline was constructed at a cost of A$70 million to evaluate the economics of mining diamonds from the diamoniferous pipes below the floor of the open pit; these reserves would be mined underground (via block caving), rather than the open pit method currently used. In late-2005 Rio Tinto Ltd concluded that the operation was economically feasible. Pre-production construction of the underground mine commenced in early to mid 2006

Economics

The Argyle diamond mine is economically feasible because its large reserves and high grade ore offsets a low average diamond weight value. The estimated value of Argyle diamond production is only US$7 per carat (US$35/g); this compares to values of 70 USD per carat ($350/g) for diamonds produced at the Diavik mine and US$170 per carat (US$850/g) at the Ekati mine, both in Canada.[1] However, Argyle has two to four times the concentration of diamonds (ore grade) of these mines. This makes extraction economically feasible, as mine costs are mostly related to the amount of ore processed, not the amount of diamond extracted.

Underground expansion

In 2005 Rio Tinto was given the go ahead to a future expansion project, moving it from an open pit to an underground mine.^[1] The project is predominantly an underground construction requiring high quality development and engineering excellence. The Block Cave is expected to operate until 2018 using the latest in mining technology, including Sandvik's auto mining technology.

The project is due to be completed by 2010.

Crater of Diamonds State Park

Crater of Diamonds State Park
IUCN Category III (Natural Monument)
Location	Pike County, Arkansas, USA
Nearest city	Murfreesboro, ArkansasNearest city: Murfreesboro, Arkansas
Coordinates	34°02′00″N 93°40′21″W / 34.0334423°N 93.6724040°W / 34.0334423; -93.6724040Coordinates: 34°02′00″N 93°40′21″W / 34.0334423°N 93.6724040°W / 34.0334423; -93.6724040
Area	911 acres (3.69 km2)
Established	1972 Established: 1972
Governing body	Arkansas State Park System

The Crater of Diamonds State Park is an Arkansas State Park located near Murfreesboro in Pike County, Arkansas, USA containing the only diamond bearing site in the world that is open to the public.

Description

The Crater of Diamonds State Park is an 911-acre (3.69 km²) Arkansas State Park situated over an eroded lamproite volcanic pipe. The park is open to the public and, for a small fee, rockhounds and visitors can dig for diamonds and other gemstones. Park visitors find more than 600 diamonds each year of all colors and grades.^[1] Over 25,000 diamonds have been found in the crater since it became a state park. Visitors may keep any gemstone they find regardless of its value (and some, as listed below, have been quite valuable).

In addition to diamonds, visitors may find semi-precious gems such as amethyst, agate, and jasper or approximately 40 other minerals such as garnet, phlogopite, quartz, baryte, and calcite.

The crater itself is a 37.5-acre (152,000 m²) plowed field. It is periodically plowed to bring the diamonds and other gemstones to the surface. The remainder of the park consists of a visitor center, interpretive Diamond Discovery Center, campground, picnic area, and Diamond Springs aquatic playground. A 1.3 mile (2 km) walking trail along the Little Missouri River is available for hikers.

The park is open throughout the year.

History

In August 1906, John Huddleston found two strange crystals on the surface of his 243-acre (0.98 km²) farm near Murfreesboro, Arkansas, and soon became known as the first person outside South Africa to find diamonds at their original source. The following month, Huddleston and his wife, Sarah, sold an option on the 243 acres (0.98 km²) to a group of Little Rock investors headed by banker-attorney Samuel F. (Sam) Reyburn, who undertook a careful, deliberate test of the property.

After 1906, several attempts at commercial diamond mining failed. The only significant yields came from the original surface layer, where erosion over a long period of time had concentrated diamonds. In the early period, 1907-1932, yields from this "black gumbo" surface material often exceeded thirty carats per hundred loads (standard 1600-pound tramload of the early period). Highest yields from the undisturbed subsurface material (described as "kimberlite" or volcanic breccia, by the U. S. Geological Survey) were two carats per hundred loads in 1908 and about two carats per hundred short tons (2000 pounds)in 1943-1944.

Because equipment of the early period usually included bottom screens with mesh larger than 1/16th, thousands of smaller diamonds were allowed to pass through. The bulk of these ended up in drainage cuts of varying depths all over the field and in the big natural drains on the east and west edges of the diamond-bearing section of the volcanic deposit (approximately 35 acres (140,000 m²) of volcanic breccia on the east side of the 80-acre (320,000 m²) "pipe"). In recent decades, those small diamonds have been the bread-and-butter of recreational diamond-digging.

Soon after the original diamond was found, a "diamond rush" created a boomtown atmosphere around Murfreesboro. According to old tales, hotels in Murfreesboro turned away 10,000 people in the space of a year. Supposedly these aspiring diamond miners formed a tent city near the mine which was named "Kimberly" in honor of the famous Kimberley diamond district in South Africa. On the other hand, all available evidence indicates the Town of Kimberly originated as a land-development venture in 1909, initiated by Mallard M. Mauney and his oldest son Walter on their land immediately south of Murfreesboro. The project failed soon afterward as the speculative boom generated by the diamond discovery collapsed. Today the Kimberly area is almost all cow pasture, owned by Mauney's descendants.

From 1951 to 1972, the crater hosted several private tourist attractions. The first, The Diamond Preserve of the United States, lasted only about one year. In late 1951, Howard A. Millar stepped in and salvaged the infant tourist industry. In April 1952, Millar and wife, Modean, launched their "Crater of Diamonds" attraction. Howard Millar, an accomplished writer and promoter, stirred unprecedented national publicity and drew enough visitors to sustain the operation. In March 1956, a visitor found the "Star of Arkansas" on the cleared surface. The rare beauty weighed 15.33 carats (3.07 g). Later, Roscoe Johnston opened a rival tourist attraction, the "Arkansas Diamond Mine," on the main part of the diamond field.

The rivalry between the two tourist operations left both in a weakened position. In 1970 the entire volcanic formation was consolidated by a private partnership which then reassigned the property to General Earth Minerals of Dallas, Texas. GEM expected to turn the property over for a profit, but ended up heavily indebted to GF Industries of Dallas. Upon default, GFI took the property in July 1971.

GEM consolidated the tourist operation as well as the property. GFI continued the attraction until it sold the 80-acre (320,000 m²) volcanic formation and some 800 acres (3.2 km²) surrounding to the State of Arkansas in March 1972, for $750,000. The tourist operation continued as the centerpiece of Crater of Diamonds State Park.

Due in part to the park, and also because Arkansas was the first place outside South Africa where diamonds were found at their original volcanic source, this special gem has come to be associated with the Natural State. A large diamond symbol has dominated the state flag since the early years. The Arkansas State Quarter, released in 2003, bears a diamond on its face.

Geology

The Crater of Diamonds volcanic pipe is part of a 95 million-year-old eroded volcano. The deeply sourced lamproite magma, from the upper mantle, brought the diamonds to the surface. The diamonds had crystallized in the cratonic root of the continent long before, and were sampled by the magma as it rose to the surface.

The lamproite diamond source is unusual, as almost all diamonds are mined from kimberlite and from alluvial deposits of diamonds weathered from kimberlite. The most prominent lamproite diamond source is the Argyle diamond mine in Australia.

Premier Mine

The Premier Mine is an underground diamond mine owned by Petra Diamonds. It is situated in the town of Cullinan, 40 kilometres east of Pretoria, Gauteng Province, South Africa. Established in 1902, it was renamed the Cullinan Diamond Mine in November 2003 in celebration of its centenary. The mine rose to prominence in 1905, when the Cullinan Diamond — at the time the largest gem diamond ever — was discovered here. It is also the only diamond mine in the world where blue diamonds have been discovered.

Premier Mine, South Africa

Modern mine operations

The discovery of the mine occurred in 1890 by a Dutchman named Fabricius. He was actually prospecting for Henry Ward, who had an option to purchase the Wessels estate within a certain amount of time. However, Mr. Ward did not have any money to actually purchase the land and could have only done so if the land held diamonds, since it would be easy to find investors for it then. Ward became very fortunate when only a small part of the Wessels estate actually fell within the Cape Colony, and it was upon that portion of the land that the mine was discovered.

Scores of sanitary pits had been dug close to the mine, but never on the mine itself, and therefore the mine had never been discovered until Fabricius dug a random hole of 10 feet deep through limestone and the yellow ground was found.

Although Ward had all the rights as agreed with Wessels when buying the bond for the land, things were not that simple. Scores of pits a few feet in size were dug, and people refused to leave the land even though they did not have any rights. The fight became more complex because the mine was only a few hundred meters from the boundary between the Colony and the Free State. It was the Free State who had given Ward all rights to the mine since under their law, all minerals found belong to the owners of the land.

In the end Ward's claim was established beyond any doubt. Money problems kept pursuing him which let him first part with 50% of the land which after some transactions ended up in the hands of De Beers. He finally parted with the other 50% as well and sold it to De Beers but under the following conditions: Ward could take over the mine for a period of five years in which he was allowed 5,000,000 loads (equal to 4,000,000 tons of diamond bearing ground). This referred to the so-called yellow ground and the first 8 feet (2.4 m) of limestone were discounted for (since limestone would not hold any diamonds).

Cullinan Diamond Mine sold to Petra Diamonds

De Beers, the world's biggest diamond producer, said on Thursday 22nd of November 2007 it had sold its historic Cullinan mine to a consortium led by Petra Diamonds.

Notable Discoveries

The Cullinan Diamond is the largest rough gem-quality diamond ever found, at 3,106.75 carats (621.35 g).[1] It was found by Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, Gauteng, South Africa, on January 25, 1905. The stone was named after Sir Thomas Cullinan, the owner of the diamond mine.

In May 2008, a sparkling 101.27 carats (20.25 g) diamond (about the size of a pingpong ball) mined from the Premier Mine sold for more than $6.2 million at Christie's in Hong Kong. Cut from a 460 carats (92 g) rough, the shield-shaped gem boasts 92 brilliant facets. While internally flawless, the stone has a slight imperfection on the surface that is imperceptible to the human eye, the auction house said. The stone sold Wednesday to a private buyer for $6.21 million, it said. It is the largest colorless diamond to appear on the auction market in the last 18 years, Christie's said. Only three colorless diamonds of more than 100 carats (20 g) have appeared at auction. All were sold in Geneva. Naming rights were granted to the new owner.

Jwaneng diamond mine

Jwaneng diamond mine
Jwaneng Diamond Mine, Botswana
Location	Kalahari Desert
Country	Botswana
Owner
Company	Debswana
Production
Products	Diamonds (14.3 million carats in 2003)
History
Opened	1982
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The Jwaneng diamond mine is the richest diamond mine in the world and is located in south-central Botswana about 170 kilometers (110 miles) west of the city of Gaborone, in the Naledi river valley of the Kalahari. Jwaneng, meaning "a place of small stones", is owned by Debswana, a partnership between the De Beers company and the government of Botswana. It is the second newest of four mines operated by the company, having begun operations in 1982.

Jwaneng is an open pit mine. The mine produces 9.3 million tons per year of ore and an additional 37 million tons per year of waste rock. The mine is located on three kimberlite pipes that converge near the surface, covering 520,000 square metres at ground level. In 2003, the mine produced 14.3 million carats (2860 kg) of diamond. The recoverable ore grade at the mine is about 1.25 carats per ton (250 mg/t). As of 2005^[update], known reserves will allow production at current levels to continue for 27 years. The high rate of diamond extraction, combined with high quality diamonds fetching excellent per weight prices, make the Jwaneng diamond mine the richest diamond mine in the world by value of recovered diamonds.

Jwaneng employs over 2,100 people. The mine also owns and operates a local hospital and Jwaneng Airport. The mine maintains an ISO 14001 certificate for environmental compliance, being the first mine in Botswana to achieve this certification in 2000. Jwaneng is known for its excellent safety record, winning multiple national and international safety awards.^[1]

High-security administration building at top

The Enhanced Thematic Mapper Plus (ETM+) instrument on NASA’s Landsat 7 satellite acquired this image of the Jwaneng Diamond Mine on May 17, 2001. The arid, flat landscape that fills most of this image appears in varying shades of brown, crisscrossed by pale beige roads. The Jwaneng Diamond Mine appears in the upper left quadrant of the picture, and a residential area appears near the bottom center.

At the center of the diamond mine, a series of concentric circles cut deeper and deeper into the ground. Surrounding the pit is a network of roads and structures related to the mining operation.

The settlement southeast of the mine contrasts with the arid landscape as much as the mine does. Here, tiny dots of green hint at trees and grassy parks. The pale beige rectangles around the perimeter of this image are probably crops or fallow fields.^[2]

The Jwaneng mining lease includes the Jwana Game Park, which includes a field unit of Cheetah Conservation Botswana. The game park is also host to the globally threatened Lappet-faced Vulture.

Catoca diamond mine

Catoca diamond mine
Satellite image of the mine from June 21st, 2001. The light red point in the north-east of the mine is a bush fire.
Country	Angola
Owner
Company	Alrosa (32.8%) Endiama (32.8%) Odebrecht (16.4%) Diamond Finance CY BV Group (16.8%)
Production
Products	Diamonds (2.6 million carats in 2001)
History
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The Catoca diamond mine is the fourth largest diamond mine in the world, and is located in Angola. The mine is owned by a consortium of international mining interests, including Endiama (the state mining company of Angola) (32.8% ownership), Alrosa of Russia (32.8%), Odebrecht of Brazil (16.4%), and the Diamond Finance CY BV Group (16.8%). The mine is located on a kimberlite pipe.

The mine had production of 1.8 million carats (360 kg) in 2000 and 2.6 million carats (520 kg) in 2001. Catoca management has been actively expanding capacity at the mine, such that the owners plan to extract as much as 5 million carats (1,000 kg) in 2005. The mine's production is 35 % gem quality, compared to a global average of 20 %; the diamonds produced at Catoca have an average value of $75 to $100 USD per carat (375 to 500 $/g). Estimated reserves are 60 million carats (12,000 kg).

Goldsmith

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A goldsmith is a metalworker who specializes in working with gold and other precious metals. Since ancient times the techniques of a Goldsmith have evolved very little in order to produce items of jewelry of quality standards. In modern times actual Goldsmiths are rare. Historically goldsmiths have also made flatware, platters, goblets, decorative and serviceable utensils, and ceremonial or religious items, but the rising prices of precious metals have curtailed the making of such items to a large degree. Goldsmiths must be skilled in forming metal through filing, soldering, sawing, forging, casting, and polishing metal. Traditionally, these skills had been passed along through apprenticeships, however, more recently Jewelry Arts Schools specializing solely in teaching goldsmithing and a multitude of skills falling under the jewelry arts umbrella are available. Many universities and junior colleges also offer goldsmithing, silversmithing and metal arts fabrication as a part of their fine arts curriculum.

The nature of gold

Coupled with aesthetic attractiveness and rarity, gold's physical properties have given gold and items made from it, an unparalleled place in human history. Gold is so malleable and ductile that even primitive tools can work it to a high level of detail. It is fairly easily "pressure welded", which is to say that two small pieces can be pounded together to make one larger piece, similar to clay. Gold is a noble metal— it does not react with most elements. That means it is usually found in its native form, that it will last virtually forever without oxidization and tarnishing, and that it is easily melted, fused and cast without the problems of oxides and gas that are problematic with bronzes, for example. Throughout history, people have found its lustre and color to be aesthetically pleasing.

Since prehistoric times, mankind has been able to simply pick up gold off the ground, and anyone with two rocks would be able to form it into some pleasing or useful item. A major part of that history has been played by those who work in gold: goldsmiths.

History

Gold has been worked by humans in all cultures where the metal is available, either indigenously or imported, and the history of these activities is extensive. Superbly made objects from the ancient cultures of Europe, Africa, India, Asia, South America, Mesoamerica, and North America grace museums and collections around the world. Some pieces date back thousands of years and were made using many techniques that are still used by modern goldsmiths.

In medieval Europe goldsmiths were organized in guilds and were usually one of the most important and wealthy of the guilds in a city. The guild kept records of members and the marks they used on their products. These records are very useful to historians, were they to survive. Goldsmiths often acted as bankers, since they dealt in gold and had sufficient security for the safe storage of valuable items. In the Middle Ages, goldsmithing normally included silversmithing as well, but the brass workers and workers in other base metals were normally in a separate guild since the trades were not allowed to overlap. Usually jewelers were goldsmiths.

The printmaking technique of engraving developed among goldsmiths in Germany around 1430, who had long used the technique on their metal pieces. The notable engravers of the 1400s either were goldsmiths, as was Master E. S., or the sons of goldsmiths, such as Martin Schongauer and Albrecht Dürer

The modern goldsmith

It has been said that goldsmithing is the only art which uses some aspect of all other arts. Thus a fully realized goldsmith might have a wide array of skills and knowledge at their disposal. Gold, being the most malleable metal of all, offers unique opportunities for the worker. In today's world a wide variety of other metals, especially platinum alloys, may also be used extensively. 24 karat gold is generally called fine gold, and is the starting place for working with gold. Usually the gold is alloyed into any of various blends and colors, and the goldsmith may have some skill in that process. Then the gold may be cast into some item, usually with the lost wax casting process, or it may be used to fabricate the work directly in metal. In the latter case, the goldsmith will use a variety of tools and machinery, including the rolling mill, the drawplate, and perhaps swage blocks and other forming tools to make the metal into shapes needed to build the intended piece. Then parts are fabricated through a wide variety of processes and assembled by soldering. It is a testament to the history and evolution of the trade that those skills have reached an extremely high level of attainment and skill over time. A fine goldsmith can and will work to a tolerance approaching that of precision machinery, but largely using only his eyes and hand tools. Quite often the goldsmith's job involves the making of mountings for gemstones, in which case they are often referred to as jewelers.

'Jeweller' however is a term mostly reserved for a person who deals in jewellery (buys and sells) and not to be confused with a goldsmith, silversmith, gemologist, diamond cutter and diamond setters.

For further insight into the art of goldsmithing see bench jewelers.

Notable goldsmiths

See Category:Goldsmiths and Category:Silversmiths

• Paul de Lamerie
• Paul Storr
• Lorenzo Ghiberti
• Benvenuto Cellini
• Johannes Gutenberg
• House of Fabergé

Jewellery

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Amber pendants

Jewellery (IPA: /ˈdʒuʊləɹi/; also spelled jewelry, see spelling differences) is an item of personal adornment, such as a necklace, ring, brooch or bracelet, that is worn by a person. It may be made from gemstones or precious metals, but may be from any other material, and may be appreciated because of geometric or other patterns, or meaningful symbols. Earrings and other body rings are also considered to be jewellery, while body art is not. Also, items affixed to a garment, such as buttons, are not considered to be jewellery, even if they are unusual and highly decorative. Also, items such as belts and handbags etc. are not considered to be jewellery, and are considered to be accessories.

The word jewellery is derived from the word jewel, which was anglicised from the Old French "jouel" circa the 13th century.^[1] Further tracing leads back to the Latin word "jocale", meaning plaything. Jewellery is one of the oldest forms of body adornment; recently found 100,000 year-old beads made from Nassarius shells are thought to be the oldest known jewellery.^[2]

Jewellery is sometimes seen as wealth storage or functionally as holding a garment or hair together. It has from very early times also been regarded as a form of personal adornment. The first pieces of jewellery were made from natural materials, such as bone, animal teeth, shell, wood and carved stone. More exotic jewellery was probably made for wealthy people or as indications of social status. In some cases people were buried with their jewellery.

Jewellery has been made to adorn nearly every body part, from hairpins to toe rings and many more types of jewellery. While high-quality jewellery is made with gemstones and precious metals, such as silver or gold, there is also a growing demand for art jewellery where design and creativity is prized above material value. In addition, there is the less costly costume jewellery, made from lower value materials and mass-produced. Other variations include wire sculpture (wrap) jewellery, using anything from base metal wire with rock tumbled stone to precious metals and precious gemstones.

Jewellery market

According to a recent KPMG study^[42] the largest jewellery market is the United States with a market share of 30.8%, Japan, India and China and the Middle East each with 8 - 9% and finally Italy with 5%. The authors of the study predict a dramatic change in market shares by 2015, where the market share of the United States will have dropped to around 25%, and China and India will increase theirs to over 13%. The Middle East will remain more or less constant at 9%, whereas Europe's and Japan's marketshare will be halved and become less than 4% for Japan, and less than 3% for the biggest individual European countries: Italy and the UK.

Gold mining

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Development of Dolaucothi Gold Mines

The aqueducts at Dolaucothi

Britain's gold mines were located in Wales at Dolaucothi. The Romans discovered the Dolaucothi vein soon after their invasion, and they used hydraulic mining methods to prospect the hillsides before discovering rich veins of gold-bearing quartzite. The remains of the several aqueducts and water tanks above the mine are still visible today. The tanks were used to hold water for hushing during prospecting for veins, and it involved releasing a wave of water to scour the ground and remove overburden, and expose the bedrock. If a vein was found, then it would be attacked using fire-setting, a method which involved building a fire against the rock. When the hot rock was quenched with water, it could be broken up easily, and the barren debris swept away using another wave of water. The technique produced numerous opencasts which are still visible in the hills above Pumsaint today. A fort, settlement and bath-house were set up nearby in the Cothi Valley. The methods were probably used elsewhere for lead and tin mining, and indeed, were used widely before explosives made them redundant. Hydraulic mining is however, still used for the extraction of alluvial tin.

Deep mining shafts were dug into the earth on two hills near Dolaucothi, after opencast methods were no longer efficient. Once the ore was removed, it would be crushed by heavy hammers, probably automated by a water wheel until reduced to a fine dust. Then, the dust would be washed in a stream of water where the rocks and other debris would be removed, the gold dust and flakes collected, and smelted into ingots. The ingots would be sent all across the Roman world, where they would be minted or put into vaults.

Production of Gold

Gold nuggets found in Arizona

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). Because 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 produced having come from South Africa. Production in 1970 accounted for 79% of the world supply, producing about 1,000 tonnes. However by 2007 production was just 272 tonnes. This sharp decline was due to the increasing difficulty of extraction, changing economic factors affecting the industry, and tightened safety auditing. In 2007 China (with 276 tonnes) overtook South Africa as the world's largest gold producer, the first time since 1905 that South Africa has not been the largest.^[18]

The entrance to an underground gold mine in Victoria, Australia

Gold ore

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 the United States, Australia, 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.^[19]

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, e.g. every cubic kilometer of water could contain 10 to 20 kg of gold). 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 the United States in the 1890s. A British fraudster ran the same scam in England in the early 1900s.^[20]

World gold production trend

Gold output in 2005

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 World War I. 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.^{[citation needed]} 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^[when?] 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 2006, it was estimated that all the gold ever mined totaled 158,000 tonnes.^[21] This can be represented by a cube with an edge length of just 20.2 meters.

Gold is so stable and so valuable that it is always recovered and recycled. There is no true "consumption" of gold in the economic sense; the stock of gold remains essentially constant while ownership shifts from one party to another.^[22]

Price

LBMA USD morning price fixings ($US per troy ounce) from Jan 2001 to Apr 2006

Gold price per ounce in USD since 1968, in actual US$ and 2006 US$.

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.

Historically gold coinage was widely used as currency; When paper money was introduced, it typically was a receipt redeemable for gold coin or bullion. 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 devalued 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 March 17, 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%^{[citation needed]} of the gold ever mined, 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.