Misplaced Pages

#981018

115-615: Element Six is a company specialised in providing synthetic diamond, cubic boron nitride and other superhard materials for industrial use. Part of the De Beers Group , Element Six employs over 1,900 people and its primary manufacturing sites are located in the UK, Ireland, Germany, South Africa, and the US. Element Six advanced engineering materials are used in abrasive applications such as cutting, grinding, drilling, shearing and polishing, while

230-486: A micron deep. This inscription helps distinguish Forevermark diamonds from other natural diamonds though, similarly to when distinguishing natural diamonds from synthetic diamonds , it requires specialist detection equipment to view. The inscription also helps maintain scarcity: the Forevermark website boasts that only a tiny percentage of diamonds qualify for the Forevermark brand. De Beers Diamond Jewellers (DBDJ)

345-491: A Christie's auction. In May 2009, a 7.03-carat (1.406 g) blue diamond fetched the highest price per carat ever paid for a diamond when it was sold at auction for 10.5 million Swiss francs (6.97 million euros, or US$ 9.5 million at the time). That record was, however, beaten the same year: a 5-carat (1.0 g) vivid pink diamond was sold for US$ 10.8 million in Hong Kong on December 1, 2009. Clarity

460-577: A South African farm named Vooruitzicht ( Dutch for "prospect" or "outlook") near Zandfontein in the Boshof District of Orange Free State . After they discovered diamonds on their land, the increasing demands of the British government forced them to sell their farm on 31 July 1871 to merchant Alfred Johnson Ebden (1820–1908) for £6,600. Vooruitzicht would become the site of the Big Hole and

575-792: A Ukrainian diamond synthesis plant which produces resin bond synthetic diamond was announced on 3 April 2006. On 19 April 2006, Element Six opened its first manufacturing site in Asia in Suzhou , China , for the production of specialized type of synthetic diamond for internal use in the manufacturing of polycrystalline products. Element Six purchased Barat Carbide, the former hard materials group of Boart Longyear in 2007 and expanded its product portfolio to include tungsten carbide parts for soft rock mining tools or as wear parts. In December 2012, Element Six announced that it has acquired US-based Megadiamond's cutting tool business from Schlumberger to become

690-453: A cigarette lighter, but house fires and blow torches are hot enough. Jewelers must be careful when molding the metal in a diamond ring. Diamond powder of an appropriate grain size (around 50   microns) burns with a shower of sparks after ignition from a flame. Consequently, pyrotechnic compositions based on synthetic diamond powder can be prepared. The resulting sparks are of the usual red-orange color, comparable to charcoal, but show

805-474: A compilation album, Diamond Music , released in 1996, which features the 'Palladio' suite. A 2010 commercial for Verizon Wireless parodied the De Beers spots. In May 2018, De Beers introduced a new brand of jewellery called "Lightbox" made with synthetic diamonds . The synthetic stones start at $ 200 for a quarter carat to $ 800 for a full carat diamond. The new lab-grown diamonds retail for about one-tenth

920-490: A concerted effort to produce synthetic diamond and, in response, a research group, called the Adamant Research Laboratory, was established and housed as a subdivision of the laboratory. Two years later, after intensive research into high-pressure and temperature techniques, a team led by Jan Custers and Henry Dyer produced successful results. Their success in the synthesis of diamonds was announced to

1035-727: A continuum with carbonatites , but the latter have too much oxygen for carbon to exist in a pure form. Instead, it is locked up in the mineral calcite ( Ca C O 3 ). All three of the diamond-bearing rocks (kimberlite, lamproite and lamprophyre) lack certain minerals ( melilite and kalsilite ) that are incompatible with diamond formation. In kimberlite , olivine is large and conspicuous, while lamproite has Ti- phlogopite and lamprophyre has biotite and amphibole . They are all derived from magma types that erupt rapidly from small amounts of melt, are rich in volatiles and magnesium oxide , and are less oxidizing than more common mantle melts such as basalt . These characteristics allow

1150-452: A diamond to fluoresce. Diamonds can fluoresce in a variety of colors including blue (most common), orange, yellow, white, green and very rarely red and purple. Although the causes are not well understood, variations in the atomic structure, such as the number of nitrogen atoms present are thought to contribute to the phenomenon. Diamonds can be identified by their high thermal conductivity (900– 2320 W·m ·K ). Their high refractive index

1265-480: A gemstone. Because it can only be scratched by other diamonds, it maintains its polish extremely well. Unlike many other gems, it is well-suited to daily wear because of its resistance to scratching—perhaps contributing to its popularity as the preferred gem in engagement or wedding rings , which are often worn every day. The hardest natural diamonds mostly originate from the Copeton and Bingara fields located in

SECTION 10

#1732791866982

1380-595: A gun named Long Cecil in the company workshops. In 1898, diamonds were discovered on farms near Pretoria , Transvaal. One led to the discovery of the Premier Mine . The Premier Mine was registered in 1902 and the Cullinan Diamond , the largest rough diamond ever discovered, was found there in 1905. (The Premier Mine was renamed the Cullinan Mine in 2003.) However, its owner refused to join

1495-469: A lab-grown diamond brand to sell jewellery directly to consumers. International Institute of Diamond Valuation Diamond Diamond is a solid form of the element carbon with its atoms arranged in a crystal structure called diamond cubic . Diamond as a form of carbon is a tasteless, odourless, strong, brittle solid, colourless in pure form, a poor conductor of electricity, and insoluble in water. Another solid form of carbon known as graphite

1610-458: A manor house in Sunninghill, Berkshire , called Charters in 1975 and used it as a research and technical support centre. Charters was sold in 2002 to a residential developer. In 1992, breakthroughs in chemical vapour deposition technology opened the opportunity to synthesize diamond films and a new raft of application areas became possible. The De Beers Industrial Diamond Division acquired

1725-475: A metallic fluid. The extreme conditions required for this to occur are present in the ice giants Neptune and Uranus . Both planets are made up of approximately 10 percent carbon and could hypothetically contain oceans of liquid carbon. Since large quantities of metallic fluid can affect the magnetic field, this could serve as an explanation as to why the geographic and magnetic poles of the two planets are unaligned. The most common crystal structure of diamond

1840-403: A pale blue flame, and continues to burn after the source of heat is removed. By contrast, in air the combustion will cease as soon as the heat is removed because the oxygen is diluted with nitrogen. A clear, flawless, transparent diamond is completely converted to carbon dioxide; any impurities will be left as ash. Heat generated from cutting a diamond will not ignite the diamond, and neither will

1955-554: A relatively high optical dispersion . Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle , although a few have come from as deep as 800 kilometres (500 mi). Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Much more recently (hundreds to tens of million years ago), they were carried to

2070-463: A transition between graphite and diamond are well established theoretically and experimentally. The equilibrium pressure varies linearly with temperature, between 1.7  GPa at 0 K and 12 GPa at 5000 K (the diamond/graphite/liquid triple point ). However, the phases have a wide region about this line where they can coexist. At standard temperature and pressure , 20 °C (293 K) and 1 standard atmosphere (0.10 MPa),

2185-467: A very linear trajectory which is explained by their high density. Diamond also reacts with fluorine gas above about 700 °C (1,292 °F). Diamond has a wide band gap of 5.5  eV corresponding to the deep ultraviolet wavelength of 225   nanometers. This means that pure diamond should transmit visible light and appear as a clear colorless crystal. Colors in diamond originate from lattice defects and impurities. The diamond crystal lattice

2300-425: A volcanic rock. There are many theories for its origin, including formation in a star, but no consensus. Diamond is the hardest material on the qualitative Mohs scale . To conduct the quantitative Vickers hardness test , samples of materials are struck with a pyramid of standardized dimensions using a known force – a diamond crystal is used for the pyramid to permit a wide range of materials to be tested. From

2415-449: Is 0.01% for nickel and even less for cobalt. Virtually any element can be introduced to diamond by ion implantation. Nitrogen is by far the most common impurity found in gem diamonds and is responsible for the yellow and brown color in diamonds. Boron is responsible for the blue color. Color in diamond has two additional sources: irradiation (usually by alpha particles), that causes the color in green diamonds, and plastic deformation of

SECTION 20

#1732791866982

2530-415: Is a solid form of pure carbon with its atoms arranged in a crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond. The two most common allotropes of pure carbon are diamond and graphite . In graphite, the bonds are sp orbital hybrids and the atoms form in planes, with each bound to three nearest neighbors, 120 degrees apart. In diamond, they are sp and

2645-462: Is a three-year, $ 3 million deal. In September 2017, De Beers partnered with UN Women to help the advancement of women within the company and the countries it operates in. In 2018, the two entities launched a program to support 500 women micro-entrepreneurs in Blouberg and Musina communities, near De Beers's Venetia diamond mine . In May 2018, De Beers's group company Element Six launched

2760-514: Is active in open-pit, underground, large-scale alluvial and coastal mining. It operates in 35 countries with mining taking place in Botswana , Namibia , South Africa, and Canada. It also has an artisanal mining business, Gemfair , which operates in Sierra Leone . From its inception in 1888 until the start of the 21st century, De Beers controlled 80% to 85% of rough diamond distribution and

2875-420: Is aided by isotopic dating and modeling of the geological history. Then surveyors must go to the area and collect samples, looking for kimberlite fragments or indicator minerals . The latter have compositions that reflect the conditions where diamonds form, such as extreme melt depletion or high pressures in eclogites . However, indicator minerals can be misleading; a better approach is geothermobarometry , where

2990-728: Is also indicative, but other materials have similar refractivity. Diamonds are extremely rare, with concentrations of at most parts per billion in source rock. Before the 20th century, most diamonds were found in alluvial deposits . Loose diamonds are also found along existing and ancient shorelines , where they tend to accumulate because of their size and density. Rarely, they have been found in glacial till (notably in Wisconsin and Indiana ), but these deposits are not of commercial quality. These types of deposit were derived from localized igneous intrusions through weathering and transport by wind or water . Most diamonds come from

3105-405: Is another mechanical property toughness , which is a material's ability to resist breakage from forceful impact. The toughness of natural diamond has been measured as 50–65  MPa ·m . This value is good compared to other ceramic materials, but poor compared to most engineering materials such as engineering alloys, which typically exhibit toughness over 80   MPa·m . As with any material,

3220-414: Is called diamond cubic . It is formed of unit cells (see the figure) stacked together. Although there are 18 atoms in the figure, each corner atom is shared by eight unit cells and each atom in the center of a face is shared by two, so there are a total of eight atoms per unit cell. The length of each side of the unit cell is denoted by a and is 3.567  angstroms . The nearest neighbor distance in

3335-402: Is exceptionally strong, and only atoms of nitrogen , boron , and hydrogen can be introduced into diamond during the growth at significant concentrations (up to atomic percents). Transition metals nickel and cobalt , which are commonly used for growth of synthetic diamond by high-pressure high-temperature techniques, have been detected in diamond as individual atoms; the maximum concentration

3450-419: Is formed of layers stacked in a repeating ABCABC ... pattern. Diamonds can also form an ABAB ... structure, which is known as hexagonal diamond or lonsdaleite , but this is far less common and is formed under different conditions from cubic carbon. Diamonds occur most often as euhedral or rounded octahedra and twinned octahedra known as macles . As diamond's crystal structure has a cubic arrangement of

3565-412: Is higher for flawless, pure crystals oriented to the <111> direction (along the longest diagonal of the cubic diamond lattice). Therefore, whereas it might be possible to scratch some diamonds with other materials, such as boron nitride , the hardest diamonds can only be scratched by other diamonds and nanocrystalline diamond aggregates . The hardness of diamond contributes to its suitability as

Element Six - Misplaced Pages Continue

3680-404: Is hybrid rock with a chaotic mixture of small minerals and rock fragments ( clasts ) up to the size of watermelons. They are a mixture of xenocrysts and xenoliths (minerals and rocks carried up from the lower crust and mantle), pieces of surface rock, altered minerals such as serpentine , and new minerals that crystallized during the eruption. The texture varies with depth. The composition forms

3795-647: Is in the form of micro/nanoscale wires or needles (~100–300   nanometers in diameter, micrometers long), they can be elastically stretched by as much as 9–10 percent tensile strain without failure, with a maximum local tensile stress of about 89–98 GPa , very close to the theoretical limit for this material. Other specialized applications also exist or are being developed, including use as semiconductors : some blue diamonds are natural semiconductors, in contrast to most diamonds, which are excellent electrical insulators . The conductivity and blue color originate from boron impurity. Boron substitutes for carbon atoms in

3910-579: Is made up of a series of joint ventures and wholly owned operations. The joint ventures are: The wholly owned operations are in southern Africa and Canada. Also wholly owned are Forevermark , De Beers Jewellers, the International Institute of Diamond Valuation, De Beers Ventures, the International Institute of Diamond Grading & Research and Element Six (Umicore has a 40% stake in Element Six's abrasives division). Forevermark

4025-477: Is one of the 4C's (color, clarity, cut and carat weight) that helps in identifying the quality of diamonds. The Gemological Institute of America (GIA) developed 11 clarity scales to decide the quality of a diamond for its sale value. The GIA clarity scale spans from Flawless (FL) to included (I) having internally flawless (IF), very, very slightly included (VVS), very slightly included (VS) and slightly included (SI) in between. Impurities in natural diamonds are due to

4140-797: Is partially oxidized. The oxidized surface can be reduced by heat treatment under hydrogen flow. That is to say, this heat treatment partially removes oxygen-containing functional groups. But diamonds (sp C) are unstable against high temperature (above about 400 °C (752 °F)) under atmospheric pressure. The structure gradually changes into sp C above this temperature. Thus, diamonds should be reduced below this temperature. At room temperature, diamonds do not react with any chemical reagents including strong acids and bases. In an atmosphere of pure oxygen, diamond has an ignition point that ranges from 690 °C (1,274 °F) to 840 °C (1,540 °F); smaller crystals tend to burn more easily. It increases in temperature from red to white heat and burns with

4255-769: Is possible to treat regular diamonds under a combination of high pressure and high temperature to produce diamonds that are harder than the diamonds used in hardness gauges. Diamonds cut glass, but this does not positively identify a diamond because other materials, such as quartz, also lie above glass on the Mohs scale and can also cut it. Diamonds can scratch other diamonds, but this can result in damage to one or both stones. Hardness tests are infrequently used in practical gemology because of their potentially destructive nature. The extreme hardness and high value of diamond means that gems are typically polished slowly, using painstaking traditional techniques and greater attention to detail than

4370-452: Is the chemically stable form of carbon at room temperature and pressure , but diamond is metastable and converts to it at a negligible rate under those conditions. Diamond has the highest hardness and thermal conductivity of any natural material, properties that are used in major industrial applications such as cutting and polishing tools. They are also the reason that diamond anvil cells can subject materials to pressures found deep in

4485-454: Is the case with most other gemstones; these tend to result in extremely flat, highly polished facets with exceptionally sharp facet edges. Diamonds also possess an extremely high refractive index and fairly high dispersion. Taken together, these factors affect the overall appearance of a polished diamond and most diamantaires still rely upon skilled use of a loupe (magnifying glass) to identify diamonds "by eye". Somewhat related to hardness

4600-612: The De Beers cartel. Instead, the mine started selling to a pair of independent dealers named Bernard and Ernest Oppenheimer , thereby weakening the De Beers stronghold. Francis Oats , who became Chairman of De Beers in 1908, was dismissive of the threats from the Premier Mine and the finds in German South West Africa . However, production soon equalled all of the De Beers mines combined. Ernest Oppenheimer

4715-739: The Earth's mantle , and most of this section discusses those diamonds. However, there are other sources. Some blocks of the crust, or terranes , have been buried deep enough as the crust thickened so they experienced ultra-high-pressure metamorphism . These have evenly distributed microdiamonds that show no sign of transport by magma. In addition, when meteorites strike the ground, the shock wave can produce high enough temperatures and pressures for microdiamonds and nanodiamonds to form. Impact-type microdiamonds can be used as an indicator of ancient impact craters. Popigai impact structure in Russia may have

Element Six - Misplaced Pages Continue

4830-566: The New England area in New South Wales , Australia. These diamonds are generally small, perfect to semiperfect octahedra, and are used to polish other diamonds. Their hardness is associated with the crystal growth form, which is single-stage crystal growth. Most other diamonds show more evidence of multiple growth stages, which produce inclusions, flaws, and defect planes in the crystal lattice, all of which affect their hardness. It

4945-606: The Orange River in South Africa. He invested the profits of this operation into buying up claims of small mining operators, with his operations soon expanding into a separate mining company. He soon secured funding from the Rothschild family , who would finance his business expansion. De Beers Consolidated Mines was formed in 1888 by the merger of the companies of Barney Barnato and Cecil Rhodes, by which time

5060-1189: The Snap Lake mine in the Northwest Territories , Canada; this was the first De Beers mine outside Africa and was Canada's first completely underground diamond mine. However, production was suspended when the mine was put on care and maintenance in 2015. De Beers opened the Victor mine in Ontario , Canada, the same year, a day after Snap Lake. This was followed by the opening of the company's third mine in Canada, Gahcho Kue , in September 2016. Trading of rough diamonds takes place through two channels – De Beers Global Sightholder Sales (GSS) and De Beers Auction Sales. GSS sells about 90% of De Beers's rough diamonds, by value, and features wholly owned and joint venture operations in South Africa (De Beers Sightholder Sales South Africa), Botswana (DTCB), and Namibia (NDTC). They sort, value and sell 33% (2013) of

5175-559: The Wawa belt of the Superior province in Canada and microdiamonds in the island arc of Japan are found in a type of rock called lamprophyre . Kimberlites can be found in narrow (1 to 4 meters) dikes and sills, and in pipes with diameters that range from about 75 m to 1.5 km. Fresh rock is dark bluish green to greenish gray, but after exposure rapidly turns brown and crumbles. It

5290-436: The lithosphere . Such depths occur below cratons in mantle keels , the thickest part of the lithosphere. These regions have high enough pressure and temperature to allow diamonds to form and they are not convecting, so diamonds can be stored for billions of years until a kimberlite eruption samples them. Host rocks in a mantle keel include harzburgite and lherzolite , two type of peridotite . The most dominant rock type in

5405-536: The normal color range , and applies a grading scale from "D" (colorless) to "Z" (light yellow). Yellow diamonds of high color saturation or a different color, such as pink or blue, are called fancy colored diamonds and fall under a different grading scale. In 2008, the Wittelsbach Diamond , a 35.56-carat (7.112 g) blue diamond once belonging to the King of Spain, fetched over US$ 24 million at

5520-402: The upper mantle , peridotite is an igneous rock consisting mostly of the minerals olivine and pyroxene ; it is low in silica and high in magnesium . However, diamonds in peridotite rarely survive the trip to the surface. Another common source that does keep diamonds intact is eclogite , a metamorphic rock that typically forms from basalt as an oceanic plate plunges into the mantle at

5635-436: The 'trilogy ring' (meant to represent the past, present, and future of a relationship) and the 'right hand ring' (meant to be bought and worn by women as a symbol of independence). De Beers ran television advertisements featuring silhouettes of people wearing diamonds, set to the music of ' Palladio ' by Karl Jenkins . The campaign, titled "Shadows and Lights" first ran in the first quarter of 1993. The song would later inspire

5750-646: The 12,000-tonne, 113-metre-long SS Nujoma, built at a cost of $ 157 million and named after Sam Nujoma, Namibia's founding president. This vessel, the world's most advanced diamond exploration and sampling vessel, began full operations in June 2017. De Beers Consolidated Mines is responsible for the De Beers mining in South Africa . It is 74% owned by De Beers and 26% by a board-based black economic empowerment partner, Ponahalo Investments. There are two mines – Venetia and Voorspoed. In 2008, De Beers began production at

5865-645: The 1980s to 29.5% in 2019. Seeing these developing trends, the Oppenheimer family announced in November 2011 its intention to sell its entire 40% stake in De Beers to Anglo American plc , thereby increasing Anglo American's ownership of the company to 85% (with the remaining 15% owned by the Government of the Republic of Botswana). The transaction was worth £3.2 billion (US$ 5.1 billion) in cash and ended

SECTION 50

#1732791866982

5980-489: The De Beers mine, two successful diamond mines. Their name, which was given to one of the mines, subsequently became associated with the company. Cecil Rhodes , the founder of the British South Africa Company , got his start by renting water pumps to miners during the diamond rush that started in 1869, when an 83.5 carat diamond called the ' Star of South Africa ' was found at Hopetown near

6095-424: The Earth. Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions are boron and nitrogen ). Small numbers of defects or impurities (about one per million of lattice atoms) can color a diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange, or red. Diamond also has a very high refractive index and

6210-561: The Oppenheimer dynasty's 80-year ownership of De Beers. In 2020, the De Beers Company released a statement of a values change, promising the world that it is committed to not using slave labor within the company. De Beers successfully advertised diamonds to manipulate consumer demand. One of the most effective marketing strategies has been the marketing of diamonds as a symbol of love and commitment. Copywriter Frances Gerety (1916–1999) working for N. W. Ayer & Son coined

6325-474: The Oppenheimers' family stake of 40% for US$ 5.1 billion (£3.2 billion) and increasing its stake to 85%, ending the 80-year Oppenheimer control of the company. In May 2024, Anglo American announced its intention to spin off or sell De Beers. The name 'De Beers' was derived from the two Dutch settlers , brothers Diederik Arnoldus de Beer (1825–1878) and Johannes Nicolaas de Beer (1830–1883), who owned

6440-473: The Republic of Botswana. It operates four mines – Jwaneng, Orapa, Letlhakane and Damtshaa, though Damtshaa was put on care and maintenance in 2015. In Namibia, mining is carried out through Namdeb Holdings , a 50–50 joint venture with the Government of the Republic of Namibia. Namdeb Holdings is made up of Debmarine Namibia (covering offshore mining) and Namdeb Diamond Corporation (land-based coastal mining). For offshore mining, motor vessels are used, including

6555-670: The United Nations. The initial focus of the UN's investigation was on Jonas Savimbi 's UNITA movement in Angola, which was found to have bartered uncut diamonds for weaponry despite international economic and diplomatic sanctions being in effect through United Nations Security Council Resolution 1173 . In 1999, De Beers Group stopped all outside buying of diamonds in order to guarantee the conflict-free status of their diamonds effective from 26 March 2000. In December 2000, following

6670-513: The aim of providing a range of services and equipment in the field of diamond verification. It is based in London, Antwerp and, from 2015, in Surat , India . The IIDGR works only on diamonds that meet the requirements of the United Nations' World Diamond Council Kimberley Process . In 1999, a campaign by Global Witness to highlight the role of diamonds in international conflicts led to a review by

6785-704: The approach in 2008 when it broke with 44 years of direct sales to hold the diamond industry's first online international auction sale. It is now the world's leader in this kind of auction sale. De Beers employs more than 30,000 people around the globe on five continents, with more than 17,000 employees in Africa. Almost 8,000 people are employed in Botswana, around 6,200 in South Africa, nearly 2,900 in Namibia, some 1,260 in Canada and about 320 in exploration. In February 2020, De Beers reported its worst set of earnings since

6900-462: The atoms form tetrahedra, with each bound to four nearest neighbors. Tetrahedra are rigid, the bonds are strong, and, of all known substances, diamond has the greatest number of atoms per unit volume, which is why it is both the hardest and the least compressible . It also has a high density, ranging from 3150 to 3530 kilograms per cubic metre (over three times the density of water) in natural diamonds and 3520 kg/m in pure diamond. In graphite,

7015-420: The atoms, they have many facets that belong to a cube , octahedron, rhombicosidodecahedron , tetrakis hexahedron , or disdyakis dodecahedron . The crystals can have rounded-off and unexpressive edges and can be elongated. Diamonds (especially those with rounded crystal faces) are commonly found coated in nyf , an opaque gum-like skin. Some diamonds contain opaque fibers. They are referred to as opaque if

SECTION 60

#1732791866982

7130-410: The bonds between nearest neighbors are even stronger, but the bonds between parallel adjacent planes are weak, so the planes easily slip past each other. Thus, graphite is much softer than diamond. However, the stronger bonds make graphite less flammable. Diamonds have been adopted for many uses because of the material's exceptional physical characteristics. It has the highest thermal conductivity and

7245-512: The carbon source is more likely carbonate rocks and organic carbon in sediments, rather than coal. Diamonds are far from evenly distributed over the Earth. A rule of thumb known as Clifford's rule states that they are almost always found in kimberlites on the oldest part of cratons , the stable cores of continents with typical ages of 2.5   billion years or more. However, there are exceptions. The Argyle diamond mine in Australia ,

7360-528: The chairman and director of Anglo-American and De Beers in December 1982. During the 20th century, De Beers used several methods to leverage its dominant position to influence the international diamond market. First, it attempted to convince independent producers to join its single channel monopoly. When that did not work, it flooded the market with diamonds similar to those of producers who refused to join in, depressing their price and undermining return for

7475-473: The closure of this office, the company was reclassified as De Beers plc in 2017, with its head office now in Jersey. It is made up of two shareholdings: Anglo American plc has an 85% shareholding and the Government of the Republic of Botswana owns 15% directly. De Beers plc is the holding company of The De Beers Group of Companies. It is involved in many parts of the diamond value chain, from mining to sales, and

7590-436: The coloration, while pure or nearly pure diamonds are transparent and colorless. Most diamond impurities replace a carbon atom in the crystal lattice , known as a carbon flaw . The most common impurity, nitrogen, causes a slight to intense yellow coloration depending upon the type and concentration of nitrogen present. The Gemological Institute of America (GIA) classifies low saturation yellow and brown diamonds as diamonds in

7705-460: The company was bought by miner Anglo American in 2012. On 4 November 2011, Anglo American plc and CHL Holdings announced their agreement for Anglo American to acquire an incremental interest in De Beers, increasing Anglo American's 45% shareholding in the world's leading diamond company to 85%. De Beers plc was originally incorporated as De Beers Société Anonyme in 2000 in Luxembourg. Following

7820-490: The company was the sole owner of all diamond mining operations in the country. In 1889, Rhodes negotiated a strategic agreement with the London-based Diamond Syndicate, which agreed to purchase a fixed quantity of diamonds at an agreed price, thereby regulating output and maintaining prices. The agreement soon proved to be very successful – for example, during the trade slump of 1891–1892, supply

7935-437: The company's valuable mines. Rhodes personally moved into the city at the onset of the siege in order to put political pressure on the British government to divert military resources towards relieving the siege rather than more strategic war objectives. Despite being at odds with the military, Rhodes placed the full resources of the company at the disposal of the defenders, manufacturing shells , defences, an armoured train and

8050-448: The compositions of minerals are analyzed as if they were in equilibrium with mantle minerals. Finding kimberlites requires persistence, and only a small fraction contain diamonds that are commercially viable. The only major discoveries since about 1980 have been in Canada. Since existing mines have lifetimes of as little as 25 years, there could be a shortage of new diamonds in the future. Diamonds are dated by analyzing inclusions using

8165-460: The cost of naturally occurring diamonds. The new brand began selling in September 2018 and the stones are produced in Gresham, Oregon , a $ 94 million facility using the region's cheap electricity, which opened in 2018 with the capacity for 500,000 rough carats of diamonds per year. Mining in Botswana takes place through the mining company Debswana , a 50–50 joint venture with the Government of

8280-441: The country's war effort during World War II. During the early 1930s, the company conducted experimental work which in large part pioneered the use of diamond drills . This was highly preferable to more expensive and rarer carbons previously in use. The Free State Gold Rush was made possible in part due to this innovation, as the fields required deep drilling to reach gold-bearing reefs . In May 1955, Ernest Oppenheimer opened

8395-598: The decay of radioactive isotopes. Depending on the elemental abundances, one can look at the decay of rubidium to strontium , samarium to neodymium , uranium to lead , argon-40 to argon-39 , or rhenium to osmium . Those found in kimberlites have ages ranging from 1 to 3.5 billion years , and there can be multiple ages in the same kimberlite, indicating multiple episodes of diamond formation. The kimberlites themselves are much younger. Most of them have ages between tens of millions and 300 million years old, although there are some older exceptions (Argyle, Premier and Wawa). Thus,

8510-477: The decision by producers in Canada and Australia to distribute diamonds outside the De Beers channel, as well as increasingly negative publicity surrounding blood diamonds , which forced De Beers to protect its image by limiting sales to its own mined products. The combination of a more fragmented and thus more competitive diamond market, increased transparency, and greater liquidity , caused De Beers's market share of rough diamonds to fall from as high as 90% in

8625-470: The diamond crystal lattice. Plastic deformation is the cause of color in some brown and perhaps pink and red diamonds. In order of increasing rarity, yellow diamond is followed by brown, colorless, then by blue, green, black, pink, orange, purple, and red. "Black", or carbonado , diamonds are not truly black, but rather contain numerous dark inclusions that give the gems their dark appearance. Colored diamonds contain impurities or structural defects that cause

8740-506: The diamond lattice is 1.732 a /4 where a is the lattice constant, usually given in Angstrøms as a = 3.567 Å, which is 0.3567 nm. A diamond cubic lattice can be thought of as two interpenetrating face-centered cubic lattices with one displaced by 1 ⁄ 4 of the diagonal along a cubic cell, or as one lattice with two atoms associated with each lattice point. Viewed from a <1 1 1> crystallographic direction , it

8855-415: The diamond lattice, donating a hole into the valence band . Substantial conductivity is commonly observed in nominally undoped diamond grown by chemical vapor deposition . This conductivity is associated with hydrogen -related species adsorbed at the surface, and it can be removed by annealing or other surface treatments. Thin needles of diamond can be made to vary their electronic band gap from

8970-407: The diamonds' surface cannot be wet by water, but can be easily wet and stuck by oil. This property can be utilized to extract diamonds using oil when making synthetic diamonds. However, when diamond surfaces are chemically modified with certain ions, they are expected to become so hydrophilic that they can stabilize multiple layers of water ice at human body temperature . The surface of diamonds

9085-432: The extreme properties of synthetic diamond beyond hardness are applied in a wide array of industrial and technology applications such as optics, power transmission, water treatment, semi-conductors, sensors and quantum information processing. Sir Ernest Oppenheimer formed Industrial Distributors in 1946, the first entity to focus on the industrial uses of natural diamond. In 1956 it was decided that De Beers should make

9200-458: The famous advertising slogan, 'A Diamond is Forever', in 1947. In 2000, Advertising Age magazine named 'A Diamond is Forever' the best advertising slogan of the 20th century. The slogan may have inspired the James Bond book, film and song title Diamonds Are Forever . Other successful campaigns include the ' eternity ring ' (meant as a symbol of continuing affection and appreciation),

9315-449: The fibers grow from a clear substrate or fibrous if they occupy the entire crystal. Their colors range from yellow to green or gray, sometimes with cloud-like white to gray impurities. Their most common shape is cuboidal, but they can also form octahedra, dodecahedra, macles, or combined shapes. The structure is the result of numerous impurities with sizes between 1 and 5 microns. These diamonds probably formed in kimberlite magma and sampled

9430-510: The hardest materials such as synthetic diamond and cubic boron nitride that are used in a wide range of cutting, grinding and drilling applications range from oil and gas exploration to machine tools, automotive part manufacturing and marble production. De Beers Group The De Beers Group is a South African–British corporation that specializes in the diamond industry, including mining, exploration, retail, inscription, grading, trading and industrial diamond manufacturing. The company

9545-408: The hardness and transparency of diamond, are the reasons that diamond anvil cells are the main tool for high pressure experiments. These anvils have reached pressures of 600 GPa . Much higher pressures may be possible with nanocrystalline diamonds. Usually, attempting to deform bulk diamond crystal by tension or bending results in brittle fracture. However, when single crystalline diamond

9660-455: The highest sound velocity. It has low adhesion and friction, and its coefficient of thermal expansion is extremely low. Its optical transparency extends from the far infrared to the deep ultraviolet and it has high optical dispersion . It also has high electrical resistance. It is chemically inert, not reacting with most corrosive substances, and has excellent biological compatibility. The equilibrium pressure and temperature conditions for

9775-458: The industry, as well as eliminating sources of excess supply. In 2018, De Beers used blockchain technology to successfully track 100 high-value diamonds. The diamonds were tracked through the manufacturing process from the mine to the retailer in order to ensure their quality and conflict-free status. In 2019, they launched their own end-to-end traceability platform called Tracr to enable all diamonds to be identified and traced as they move from

9890-423: The kimberlites formed independently of the diamonds and served only to transport them to the surface. Kimberlites are also much younger than the cratons they have erupted through. The reason for the lack of older kimberlites is unknown, but it suggests there was some change in mantle chemistry or tectonics. No kimberlite has erupted in human history. Most gem-quality diamonds come from depths of 150–250 km in

10005-474: The largest producer of diamonds by weight in the world, is located in a mobile belt , also known as an orogenic belt , a weaker zone surrounding the central craton that has undergone compressional tectonics. Instead of kimberlite , the host rock is lamproite . Lamproites with diamonds that are not economically viable are also found in the United States, India, and Australia. In addition, diamonds in

10120-557: The largest supplier of abrasive supermaterials for the Automotive and Aerospace sectors. In 2012, Element Six announced to build a Global Innovation Centre near Oxford in the United Kingdom , which was opened in 2013. Products offered by Element Six fall into two broad categories: superabrasives and advanced diamond products. The largest part of the company's business today is in superabrasives. These products are based on

10235-467: The macroscopic geometry of a diamond contributes to its resistance to breakage. Diamond has a cleavage plane and is therefore more fragile in some orientations than others. Diamond cutters use this attribute to cleave some stones before faceting them. "Impact toughness" is one of the main indexes to measure the quality of synthetic industrial diamonds. Diamond has compressive yield strength of 130–140   GPa. This exceptionally high value, along with

10350-591: The melting point of diamond increases slowly with increasing pressure; but at pressures of hundreds of GPa, it decreases. At high pressures, silicon and germanium have a BC8 body-centered cubic crystal structure, and a similar structure is predicted for carbon at high pressures. At 0 K , the transition is predicted to occur at 1100 GPa . Results published in an article in the scientific journal Nature Physics in 2010 suggest that, at ultra-high pressures and temperatures (about 10 million atmospheres or 1 TPa and 50,000 °C), diamond melts into

10465-579: The melts to carry diamonds to the surface before they dissolve. Kimberlite pipes can be difficult to find. They weather quickly (within a few years after exposure) and tend to have lower topographic relief than surrounding rock. If they are visible in outcrops, the diamonds are never visible because they are so rare. In any case, kimberlites are often covered with vegetation, sediments, soils, or lakes. In modern searches, geophysical methods such as aeromagnetic surveys , electrical resistivity , and gravimetry , help identify promising regions to explore. This

10580-547: The mine to the store. Signet and the Russian-based Alrosa are using the technology. In August 2017, De Beers partnered with the Stanford Graduate School of Business to accelerate business ventures to market in Botswana, Namibia, and South Africa. As part of two programs, the partnership is set to help teach early entrepreneurs how to commercialize their business ideas. The partnership

10695-524: The new headquarters which combined the operations of Anglo American and the De Beers group. After Ernest died in November 1957, operation of Anglo and De Beers were passed on to his son, Harry Oppenheimer . Under Harry, the company expanded to several different countries around the globe, including Canada, Australia , Malaysia , Portugal , Zambia , and Tanzania . In South Africa, Harry opposed apartheid , arguing that it hindered economic growth. Despite this, De Beers has been criticized for profiting from

10810-469: The normal 5.6 eV to near zero by selective mechanical deformation. High-purity diamond wafers 5 cm in diameter exhibit perfect resistance in one direction and perfect conductance in the other, creating the possibility of using them for quantum data storage. The material contains only 3 parts per million of nitrogen. The diamond was grown on a stepped substrate, which eliminated cracking. Diamonds are naturally lipophilic and hydrophobic , which means

10925-620: The presence of natural minerals and oxides. The clarity scale grades the diamond based on the color, size, location of impurity and quantity of clarity visible under 10x magnification. Inclusions in diamond can be extracted by optical methods. The process is to take pre-enhancement images, identifying the inclusion removal part and finally removing the diamond facets and noises. Between 25% and 35% of natural diamonds exhibit some degree of fluorescence when examined under invisible long-wave ultraviolet light or higher energy radiation sources such as X-rays and lasers. Incandescent lighting will not cause

11040-589: The recommendations of the Fowler Report , the UN adopted the landmark General Assembly Resolution A/RES/55/56 supporting the creation of an international certification scheme for rough diamonds. By November 2002, negotiations between governments, the international diamond industry, led by De Beers, and civil society organisations resulted in the creation of the Kimberley Process Certification Scheme (KPCS), which sets out

11155-497: The requirements for controlling rough diamond production and trade and became effective in 2003. De Beers states that 100% of the diamonds it now sells are conflict-free and that all De Beers diamonds are purchased in compliance with national law, the Kimberley Process Certification Scheme and its own Diamond Best Practice Principles. The Kimberley process has helped restore the reputation of

11270-466: The resistant. It also purchased and stockpiled diamonds produced by other manufacturers as well as surplus diamonds in order to control prices by limiting supply . Finally, it bought diamonds when prices fell considerably naturally, to constrict supply and drive their value back up, such as during the Great Depression. In 2000, the De Beers business model changed because of factors such as

11385-529: The size of the resulting indentation, a Vickers hardness value for the material can be determined. Diamond's great hardness relative to other materials has been known since antiquity, and is the source of its name. This does not mean that it is infinitely hard, indestructible, or unscratchable. Indeed, diamonds can be scratched by other diamonds and worn down over time even by softer materials, such as vinyl phonograph records . Diamond hardness depends on its purity, crystalline perfection, and orientation: hardness

11500-419: The stable phase of carbon is graphite, but diamond is metastable and its rate of conversion to graphite is negligible. However, at temperatures above about 4500 K , diamond rapidly converts to graphite. Rapid conversion of graphite to diamond requires pressures well above the equilibrium line: at 2000 K , a pressure of 35 GPa is needed. Above the graphite–diamond–liquid carbon triple point,

11615-533: The super-abrasive distribution business from company Ernst Winter in Germany in 1996, as well as Winter“s joint ventures in other countries. A new diamond research laboratory was officially opened in Springs, Gauteng , by South African President Thabo Mbeki on 1 November 2001. In 2002, the company changed its name to Element Six. The acquisition of a majority of the shareholding of OJSC "Poltava Diamond Plant",

11730-524: The surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites . Synthetic diamonds can be grown from high-purity carbon under high pressures and temperatures or from hydrocarbon gases by chemical vapor deposition (CVD). Imitation diamonds can also be made out of materials such as cubic zirconia and silicon carbide . Natural, synthetic, and imitation diamonds are most commonly distinguished using optical techniques or thermal conductivity measurements. Diamond

11845-416: The system during the apartheid period. By 1973, Anglo and De Beers accounted for 10 percent of South Africa's gross national product and 30 percent of the country's exports. Throughout the 1960s and 1970s, De Beers attempted to secretly enter the United States' diamond market, being forced to divest its American assets in 1975 to avoid the risk of violating anti-trust laws. Harry Oppenheimer stepped down as

11960-454: The volatiles. Diamonds can also form polycrystalline aggregates. There have been attempts to classify them into groups with names such as boart , ballas , stewartite, and framesite, but there is no widely accepted set of criteria. Carbonado, a type in which the diamond grains were sintered (fused without melting by the application of heat and pressure), is black in color and tougher than single crystal diamond. It has never been observed in

12075-702: The world in 1959 by Harry Oppenheimer . A full-scale plant to produce synthetic industrial diamonds commercially started operation in Springs, Gauteng , in 1961, followed by a second plant in Shannon, County Clare , in May 1963. These two developments gave birth to the De Beers Industrial Diamonds group. By the 1960s, the company was offering a range of diamond grit products that was followed by nickel and coated diamond materials plus grinding products based on cubic boron nitride. The company acquired

12190-550: The world's diamond production. Ernest Oppenheimer took over the chairmanship of the company in 1929, after buying shares and being appointed to the board in 1926. Oppenheimer was very concerned about the discovery of diamonds in 1908 in German South West Africa , fearing that the increased supply would swamp the market and force prices down. Former CIA chief Admiral Stansfield Turner claimed that De Beers restricted US access to industrial diamonds needed for

12305-430: The world's largest diamond deposit, estimated at trillions of carats, and formed by an asteroid impact. A common misconception is that diamonds form from highly compressed coal . Coal is formed from buried prehistoric plants, and most diamonds that have been dated are far older than the first land plants . It is possible that diamonds can form from coal in subduction zones , but diamonds formed in this way are rare, and

12420-444: The world's rough diamonds by value. There are two main types of customers for rough diamonds – Sightholders and Accredited Buyers. Sightholders have a term contract. Accredited Buyer status, introduced in 2015, allows companies that are not traditional Sightholders to access diamonds that were not allocated to existing Sightholders. De Beers also sells about 10% of its rough diamonds through online auction sales. The company pioneered

12535-481: Was appointed the local agent for the powerful London Syndicate, rising to the position of mayor of Kimberley within 10 years. He understood the core principle that underpinned De Beers's success, stating in 1910 that "common sense tells us that the only way to increase the value of diamonds is to make them scarce, that is to reduce production". During World War I, the Premier Mine was finally absorbed into De Beers. When Rhodes died in 1902, De Beers controlled 90% of

12650-611: Was considered a monopoly . By 2000, the company's control of the world diamond supply decreased to 63%. The company was founded in 1888 by British businessman Cecil Rhodes , who was financed by the South African diamond magnate Alfred Beit and the London-based N M Rothschild & Sons bank. In 1926, Ernest Oppenheimer , a German immigrant to Britain and later South Africa who had earlier founded mining company Anglo American with American financier J. P. Morgan ,

12765-415: Was elected to the board of De Beers. He built and consolidated the company's global monopoly over the diamond industry until his death in 1957. During this time, he was involved in several controversies, including price fixing and trust behaviour, and was accused of not releasing industrial diamonds for the US war effort during World War II. In 2011, Anglo American took control of De Beers after buying

12880-527: Was established in 2001 as a 50:50 joint venture between The De Beers Group of Companies and LVMH , the French luxury goods company. The first De Beers boutique opened in 2002 on London's Old Bond Street as the brand's flagship store. Since then, stores have opened in various cities around the world. In March 2017, The De Beers Group of Companies acquired LVMH's 50% shareholding in DBDJ and new name De Beers Jewellers

12995-403: Was launched in 2008 as one of the two diamond brands from The De Beers Group of Companies. According to the company website, "Each Forevermark diamond is inscribed with a promise: that it is beautiful, rare and responsibly sourced." Forevermark diamonds are inscribed with an icon and unique identification number, albeit invisibly to the naked eye: the Forevermark inscription is 1 ⁄ 20 th of

13110-419: Was simply curtailed to maintain the price. Rhodes was concerned about the break-up of the new monopoly, stating to shareholders in 1896 that the company's "only risk is the sudden discovery of new mines, which human nature will work recklessly to the detriment of us all". The Second Boer War proved to be a challenging time for the company. Kimberley was besieged as soon as war broke out, thereby threatening

13225-427: Was unveiled. De Beers Ventures De Beers Ventures was established by De Beers Group in June 2017 to consider minority stake investments in start-ups and growth companies that could be of benefit to De Beers Group or the broader diamond sector. The International Institute of Diamond Grading & Research The International Institute of Diamond Grading & Research (IIDGR) was set up by De Beers in 2008, with

#981018