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66-631: First known as the " Unnamed Brown ", the Golden Jubilee Diamond was cut from a large brown diamond of 755.5 carats (151 g), found in the prolific blue ground of the Premier Mine in South Africa in 1985. Until 1990, the diamond remained largely unknown to the outside world, requiring two years' work to bring it to its current state. A large surface and deep cracks from the interior, as well as several inclusions, meant that cutting and polishing

132-484: A matte for further refining. Hydrometallurgical techniques are also used. Most sulfide deposits have traditionally been processed by concentration through a froth flotation process followed by pyrometallurgical extraction. The nickel matte is further processed with the Sherritt-Gordon process . First, copper is removed by adding hydrogen sulfide , leaving a concentrate of cobalt and nickel. Then, solvent extraction

198-399: A compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation , cathodes for rechargeable batteries, pigments and metal surface treatments. Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site . Nickel is a silvery-white metal with a slight golden tinge that takes a high polish. It

264-489: A diamond cutter and fine jewelry importer in the 1950s and 1960s, rebranded brown diamonds in order to entice sales. Names included champagne, amber, cognac and chocolate. Other companies followed the Baumgold Bros. lead and named different shades clove, coffee, caramel, cappuccino, mocha, espresso, cinnamon and even tobacco. This rebranding had some initial success, but ultimately the massive number of names caused confusion in

330-448: A laser on the girdles of every treated diamond. In 2004, however, the GE diamond section was purchased by Littlejohn & Co. and renamed Diamond Innovations . Since 1999, several companies around the world have adopted the technique and use various brand names for the processed diamonds. Nickel Nickel is a chemical element ; it has symbol Ni and atomic number 28. It

396-702: A public controversy regarding the problems of people with nickel allergy . An estimated 3.6 million tonnes (t) of nickel per year are mined worldwide; Indonesia (1,800,000 t), the Philippines (400,000 t), Russia (200,000 t), New Caledonia ( France ) (230,000 t), Canada (180,000 t) and Australia (160,000 t) are the largest producers as of 2023. The largest nickel deposits in non-Russian Europe are in Finland and Greece . Identified land-based sources averaging at least 1% nickel contain at least 130 million tonnes of nickel. About 60%

462-497: Is Ni with 28 protons and 50 neutrons. Both are therefore unusually stable for nuclei with so large a proton–neutron imbalance . Nickel-63 is a contaminant found in the support structure of nuclear reactors. It is produced through neutron capture by nickel-62. Small amounts have also been found near nuclear weapon test sites in the South Pacific. Nickel ores are classified as oxides or sulfides. Oxides include laterite , where

528-411: Is $ 0.045 (90% of the face value). In the 21st century, the high price of nickel has led to some replacement of the metal in coins around the world. Coins still made with nickel alloys include one- and two- euro coins , 5¢, 10¢, 25¢, 50¢, and $ 1 U.S. coins , and 20p, 50p, £1, and £2 UK coins . From 2012 on the nickel-alloy used for 5p and 10p UK coins was replaced with nickel-plated steel. This ignited

594-417: Is a 3d 4s energy level, specifically the 3d ( F) 4s F, J  = 4 level. However, each of these two configurations splits into several energy levels due to fine structure , and the two sets of energy levels overlap. The average energy of states with [Ar] 3d 4s is actually lower than the average energy of states with [Ar] 3d 4s . Therefore, the research literature on atomic calculations quotes

660-714: Is a new nickel mine in Michigan's Upper Peninsula . Construction was completed in 2013, and operations began in the third quarter of 2014. In the first full year of operation, the Eagle Mine produced 18,000 t. Nickel is obtained through extractive metallurgy : it is extracted from ore by conventional roasting and reduction processes that yield metal of greater than 75% purity. In many stainless steel applications, 75% pure nickel can be used without further purification, depending on impurities. Traditionally, most sulfide ores are processed using pyrometallurgical techniques to produce

726-490: Is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal . Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks , and in

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792-497: Is a volatile, highly toxic liquid at room temperature. On heating, the complex decomposes back to nickel and carbon monoxide: This behavior is exploited in the Mond process for purifying nickel, as described above. The related nickel(0) complex bis(cyclooctadiene)nickel(0) is a useful catalyst in organonickel chemistry because the cyclooctadiene (or cod ) ligands are easily displaced. Nickel(I) complexes are uncommon, but one example

858-667: Is currently being set in place by the International Seabed Authority to ensure that these nodules are collected in an environmentally conscientious manner while adhering to the United Nations Sustainable Development Goals . The one place in the United States where nickel has been profitably mined is Riddle, Oregon , with several square miles of nickel-bearing garnierite surface deposits. The mine closed in 1987. The Eagle mine project

924-470: Is greater than both Fe and Fe , more abundant nuclides often incorrectly cited as having the highest binding energy. Though this would seem to predict nickel as the most abundant heavy element in the universe, the high rate of photodisintegration of nickel in stellar interiors causes iron to be by far the most abundant. Nickel-60 is the daughter product of the extinct radionuclide Fe (half-life 2.6 million years). Due to

990-558: Is in laterites and 40% is in sulfide deposits. Also, extensive nickel sources are found in the depths of the Pacific Ocean , especially in an area called the Clarion Clipperton Zone in the form of polymetallic nodules peppering the seafloor at 3.5–6 km below sea level . These nodules are composed of numerous rare-earth metals and are estimated to be 1.7% nickel. With advances in science and engineering , regulation

1056-555: Is likely that this stone would fetch a significantly higher price, such additional value gained from affiliation with prominent individuals (Thailand royalty). Brown diamonds Brown diamonds are the most common color variety of natural diamonds . In most mines, brown diamonds account for 15% of production. The brown color makes them less attractive to some people as gemstones, and most are used for industrial purposes. However, improved marketing programs, especially in Australia and

1122-582: Is lower in other mines, but it is almost always a significant part of the total production. Consequently, scientific research has intensified on causes of brown color in diamond and ways to alter it. Irradiation of diamond by high-energy particles ( electrons , ions , neutrons or gamma rays ) produces vacancies in the diamond lattice by ejecting carbon atoms. Those vacancies produce green color centers in pure transparent diamond and yellow-green color in yellow diamonds. The color of yellow diamonds results from small numbers of nitrogen atoms replacing carbon in

1188-455: Is now Syria have been found to contain as much as 2% nickel. Some ancient Chinese manuscripts suggest that "white copper" ( cupronickel , known as baitong ) was used there in 1700–1400 BCE. This Paktong white copper was exported to Britain as early as the 17th century, but the nickel content of this alloy was not discovered until 1822. Coins of nickel-copper alloy were minted by Bactrian kings Agathocles , Euthydemus II , and Pantaleon in

1254-434: Is now known as the mineral nickeline (formerly niccolite ), a nickel arsenide . In 1751, Baron Axel Fredrik Cronstedt tried to extract copper from kupfernickel at a cobalt mine in the village of Los, Sweden , and instead produced a white metal that he named nickel after the spirit that had given its name to the mineral. In modern German, Kupfernickel or Kupfer-Nickel designates the alloy cupronickel . Originally,

1320-412: Is one of only four elements that are ferromagnetic at or near room temperature; the others are iron, cobalt and gadolinium . Its Curie temperature is 355 °C (671 °F), meaning that bulk nickel is non-magnetic above this temperature. The unit cell of nickel is a face-centered cube ; it has lattice parameter of 0.352 nm, giving an atomic radius of 0.124 nm. This crystal structure

1386-469: Is produced by the silicon burning process and later set free in large amounts in type Ia supernovae . The shape of the light curve of these supernovae at intermediate to late-times corresponds to the decay via electron capture of Ni to cobalt -56 and ultimately to iron-56. Nickel-59 is a long-lived cosmogenic radionuclide ; half-life 76,000 years. Ni has found many applications in isotope geology . Ni has been used to date

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1452-569: Is stable to pressures of at least 70 GPa. Nickel is hard, malleable and ductile , and has a relatively high electrical and thermal conductivity for transition metals. The high compressive strength of 34 GPa, predicted for ideal crystals, is never obtained in the real bulk material due to formation and movement of dislocations . However, it has been reached in Ni nanoparticles . Nickel has two atomic electron configurations , [Ar] 3d 4s and [Ar] 3d 4s , which are very close in energy; [Ar] denotes

1518-446: Is the tetrahedral complex NiBr(PPh 3 ) 3 . Many nickel(I) complexes have Ni–Ni bonding, such as the dark red diamagnetic K 4 [Ni 2 (CN) 6 ] prepared by reduction of K 2 [Ni 2 (CN) 6 ] with sodium amalgam . This compound is oxidized in water, liberating H 2 . It is thought that the nickel(I) oxidation state is important to nickel-containing enzymes, such as [NiFe]-hydrogenase , which catalyzes

1584-475: Is used as the cathode in many rechargeable batteries , including nickel–cadmium , nickel–iron , nickel–hydrogen , and nickel–metal hydride , and used by certain manufacturers in Li-ion batteries . Ni(IV) remains a rare oxidation state and very few compounds are known. Ni(IV) occurs in the mixed oxide BaNiO 3 . Unintentional use of nickel can be traced back as far as 3500 BCE. Bronzes from what

1650-455: Is used chiefly in alloys and corrosion-resistant plating. About 68% of world production is used in stainless steel . A further 10% is used for nickel-based and copper-based alloys, 9% for plating, 7% for alloy steels, 3% in foundries, and 4% in other applications such as in rechargeable batteries, including those in electric vehicles (EVs). Nickel is widely used in coins , though nickel-plated objects sometimes provoke nickel allergy . As

1716-412: Is used to separate the cobalt and nickel, with the final nickel content greater than 86%. A second common refining process is leaching the metal matte into a nickel salt solution, followed by electrowinning the nickel from solution by plating it onto a cathode as electrolytic nickel. The purest metal is obtained from nickel oxide by the Mond process , which gives a purity of over 99.99%. The process

1782-858: The Central Department Store in Lat Phrao (Bangkok), and internationally in Basel (Switzerland), Borsheims in Omaha , Nebraska, USA (owned by Warren Buffett 's Berkshire Hathaway Inc. ), and Gleims Jewelers in Palo Alto , California. USA. It is now located in the Grand Palace as part of the Royal regalia . The value of the Golden Jubilee diamond is believed to range between $ 4 and $ 12 million USD. If sold at auction, it

1848-467: The arsenide niccolite . Identified land-based resources throughout the world averaging 1% nickel or greater comprise at least 130 million tons of nickel (about the double of known reserves). About 60% is in laterites and 40% in sulfide deposits. On geophysical evidence, most of the nickel on Earth is believed to be in Earth's outer and inner cores . Kamacite and taenite are naturally occurring alloys of iron and nickel. For kamacite,

1914-484: The metal aquo complex [Ni(H 2 O) 6 ] . The four halides form nickel compounds, which are solids with molecules with octahedral Ni centres. Nickel(II) chloride is most common, and its behavior is illustrative of the other halides. Nickel(II) chloride is made by dissolving nickel or its oxide in hydrochloric acid . It is usually found as the green hexahydrate, whose formula is usually written NiCl 2 ·6H 2 O . When dissolved in water, this salt forms

1980-479: The metal aquo complex [Ni(H 2 O) 6 ] . Dehydration of NiCl 2 ·6H 2 O gives yellow anhydrous NiCl 2 . Some tetracoordinate nickel(II) complexes, e.g. bis(triphenylphosphine)nickel chloride , exist both in tetrahedral and square planar geometries. The tetrahedral complexes are paramagnetic ; the square planar complexes are diamagnetic . In having properties of magnetic equilibrium and formation of octahedral complexes, they contrast with

2046-531: The 2nd century BCE, possibly out of the Chinese cupronickel. In medieval Germany, a metallic yellow mineral was found in the Ore Mountains that resembled copper ore. But when miners were unable to get any copper from it, they blamed a mischievous sprite of German mythology, Nickel (similar to Old Nick ), for besetting the copper. They called this ore Kupfernickel from German Kupfer 'copper'. This ore

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2112-581: The United States, have resulted in brown diamonds becoming valued as gemstones and even referred to as chocolate diamonds . A significant portion of the output of Australian diamond mines is brown stones. There are several causes for the brown color, including irradiation treatment, nickel impurities and lattice defects associated with plastic deformation; the last is the predominant cause, especially in pure diamonds. A high-pressure high-temperature treatment can heal lattice defects and convert brown diamonds into yellow or even colorless stones. Baumgold Bros.,

2178-498: The United States, the term "nickel" or "nick" originally applied to the copper-nickel Flying Eagle cent , which replaced copper with 12% nickel 1857–58, then the Indian Head cent of the same alloy from 1859 to 1864. Still later, in 1865, the term designated the three-cent nickel , with nickel increased to 25%. In 1866, the five-cent shield nickel (25% nickel, 75% copper) appropriated the designation, which has been used ever since for

2244-516: The United States. In March 1999, Pegasus Overseas Ltd (POL) from Antwerp , Belgium , a subsidiary of Lazare Kaplan International , started marketing such diamonds that were processed by General Electric (GE). Those diamonds therefore received the name GE POL (or GEPOL ) and were marketed in the US as Bellataire diamonds. The existence and identity of the treatment process was considered so important that micrometer-sized letters "GEPOL" were inscribed with

2310-659: The Vatican to receive a papal blessing. It was also blessed by the Buddhist Supreme Patriarch of Thailand . The diamond ( Thai : เพชรกาญจนาภิเษก ) was named by King Bhumibol Adulyadej and given to him in honour of his 50th coronation anniversary. It was initially planned to mount the Golden Jubilee in the royal sceptre. A subsequent plan was to mount it in a royal seal . The Golden Jubilee Diamond has been exhibited at Henry Ho's 59-story Jewelry Trade Center in Bangkok ,

2376-497: The alloy is usually in the proportion of 90:10 to 95:5, though impurities (such as cobalt or carbon ) may be present. Taenite is 20% to 65% nickel. Kamacite and taenite are also found in nickel iron meteorites . Nickel is commonly found in iron meteorites as the alloys kamacite and taenite . Nickel in meteorites was first detected in 1799 by Joseph-Louis Proust , a French chemist who then worked in Spain. Proust analyzed samples of

2442-486: The color of the notable diamonds described above. The concept that brown color might be related to lattice imperfections has led to a technique to convert brown diamonds into more valued light-yellow or even colorless ones: the diamond is subjected to high pressures of 6–10 GPa and temperatures above 1600 °C that heals (anneals) those defects. The technique has been demonstrated in several research laboratories in Russia and

2508-427: The colourless D-colour Centenary . Because of its cracks and inclusions, it was decided by De Beers and Gabriel Tolkowsky to construct an underground room that was free from vibration before work could begin on the diamond. In 1990, after two years of work, the stone was finished, reduced in total from 755.50 carats, to 545.65 carats. Gabi Tolkowsky described the cut as a "Fire-Rose cushion shape". The unnamed diamond

2574-464: The complete argon core structure. There is some disagreement on which configuration has the lower energy. Chemistry textbooks quote nickel's electron configuration as [Ar] 4s 3d , also written [Ar] 3d 4s . This configuration agrees with the Madelung energy ordering rule , which predicts that 4s is filled before 3d. It is supported by the experimental fact that the lowest energy state of the nickel atom

2640-683: The development of the Argyle diamond mine in Australia in 1986, most brown diamonds were considered worthless for jewelry; they were not even assessed on the diamond color scale, and were predominantly used for industrial purposes. However, marketing strategies changed in the 1980s and brown diamonds have become popular gems. The change was mostly due to supply: the Argyle mine, with its 35 million carats (7,000 kg) of diamonds per year, makes about one third of global production of natural diamonds; 80% of Argyle diamonds are brown. The percentage of brown diamonds

2706-484: The divalent complexes of the heavier group 10 metals, palladium(II) and platinum(II), which form only square-planar geometry. Nickelocene has an electron count of 20. Many chemical reactions of nickelocene tend to yield 18-electron products. Many Ni(III) compounds are known. Ni(III) forms simple salts with fluoride or oxide ions. Ni(III) can be stabilized by σ-donor ligands such as thiols and organophosphines . Ni(III) occurs in nickel oxide hydroxide , which

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2772-691: The earth's crust exists as oxides, economically more important nickel ores are sulfides, especially pentlandite . Major production sites include the Sudbury region , Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific , Western Australia , and Norilsk , Russia. Nickel is one of four elements (the others are iron , cobalt , and gadolinium ) that are ferromagnetic at about room temperature. Alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets . The metal

2838-479: The ground state configuration as [Ar] 3d 4s . The isotopes of nickel range in atomic weight from 48  u ( Ni ) to 82 u ( Ni ). Natural nickel is composed of five stable isotopes , Ni , Ni , Ni , Ni and Ni , of which Ni is the most abundant (68.077% natural abundance ). Nickel-62 has the highest binding energy per nucleon of any nuclide : 8.7946 MeV/nucleon. Its binding energy

2904-461: The interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron , a reflection of the origin of those elements as major end products of supernova nucleosynthesis . An iron–nickel mixture is thought to compose Earth's outer and inner cores . Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel

2970-668: The large deposits in the Sudbury Basin in Canada in 1883, in Norilsk -Talnakh in Russia in 1920, and in the Merensky Reef in South Africa in 1924 made large-scale nickel production possible. Aside from the aforementioned Bactrian coins, nickel was not a component of coins until the mid-19th century. 99.9% nickel five-cent coins were struck in Canada (the world's largest nickel producer at

3036-529: The large diamond presented challenges. De Beers considered this as an opportunity to test new cutting technologies. The same technology used in cutting the future Golden Jubilee diamond was later used in the cutting of the Centenary Diamond , a smaller (273.85 carats) flawless and colorless rough diamond. Gabriel Tolkowsky was hired by De Beers to cut the diamond and also so he could test special tools and cutting methods that were being developed for use on

3102-484: The lattice as single atoms and induces yellow color. Nickel is often added to graphite to accelerate its conversion into diamond. Incorporation of nickel and nitrogen into diamond induces brown color. Nickel is easily detectable by characteristic, sharp optical absorption and luminescence signals making such diamonds easily identifiable. Whereas the brown color due to irradiation or nickel impurity can be easily recognized through spectroscopic (e.g. absorption) measurements,

3168-469: The lattice. Heating the irradiated diamonds to temperatures above 600 °C results in brown color associated with aggregation of the vacancies, with or without nitrogen involved. Such irradiation and annealing treatment can occur in nature because diamonds are often accompanied by uranium-containing ores which emit alpha particles. However, the thus produced color is restricted to a thin surface layer of few micrometers. Homogeneous color can be produced if

3234-772: The long half-life of Fe , its persistence in materials in the Solar System may generate observable variations in the isotopic composition of Ni . Therefore, the abundance of Ni in extraterrestrial material may give insight into the origin of the Solar System and its early history. At least 26 nickel radioisotopes have been characterized; the most stable are Ni with half-life 76,000 years, Ni (100 years), and Ni (6 days). All other radioisotopes have half-lives less than 60 hours and most these have half-lives less than 30 seconds. This element also has one meta state . Radioactive nickel-56

3300-491: The majority of natural brown diamonds do not show any characteristic absorption peaks. Whereas the consensus has been reached that the color relates to the plastic deformation, the particular reason has been reliably identified (large clusters of vacancies) only in type IIa natural brown diamond. Other recent results suggest that these large clusters of vacancies (mini-voids) are a likely cause in other types of diamond as well. Those lattice defects are most likely responsible for

3366-400: The marketplace. In 1986, massive amounts of brown diamonds were brought to the market. Rio Tinto opened the Argyle mine in Australia, in which 80% of the diamonds mined were brown in color. DeBeers followed this trend and in 1996 introduced massive number of brown diamonds to the market. These brown diamonds were previously used only for industrial purposes. The value of brown diamonds

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3432-416: The metals at a profit. The United States Mint , anticipating this practice, implemented new interim rules on December 14, 2006, subject to public comment for 30 days, which criminalized the melting and export of cents and nickels. Violators can be punished with a fine of up to $ 10,000 and/or a maximum of five years in prison. As of September 19, 2013, the melt value of a US nickel (copper and nickel included)

3498-446: The meteorite from Campo del Cielo (Argentina), which had been obtained in 1783 by Miguel Rubín de Celis, discovering the presence in them of nickel (about 10%) along with iron. The most common oxidation state of nickel is +2, but compounds of Ni , Ni , and Ni are well known, and the exotic oxidation states Ni and Ni have been characterized. Nickel tetracarbonyl (Ni(CO) 4 ), discovered by Ludwig Mond ,

3564-505: The only source for nickel was the rare Kupfernickel. Beginning in 1824, nickel was obtained as a byproduct of cobalt blue production. The first large-scale smelting of nickel began in Norway in 1848 from nickel-rich pyrrhotite . The introduction of nickel in steel production in 1889 increased the demand for nickel; the nickel deposits of New Caledonia , discovered in 1865, provided most of the world's supply between 1875 and 1915. The discovery of

3630-553: The people to celebrate the 50th anniversary of the King's ascent to the throne. The diamond was named the Golden Jubilee, and was received by the King's daughter, Princess Maha Chakri Sirindhorn, on his behalf in 2000. The diamond is now on display in the Royal Museum at Pimammek Golden Temple Throne Hall in Bangkok as part of the crown jewels. The diamond was brought to Pope John Paul II in

3696-407: The principal mineral mixtures are nickeliferous limonite , (Fe,Ni)O(OH), and garnierite (a mixture of various hydrous nickel and nickel-rich silicates). Nickel sulfides commonly exist as solid solutions with iron in minerals such as pentlandite and pyrrhotite with the formula Fe 9-x Ni x S 8 and Fe 7-x Ni x S 6 , respectively. Other common Ni-containing minerals are millerite and

3762-409: The retailer, Signet Jewelers. The brand heavily advertised the 'chocolate diamond' line including a massive TV media spend. The campaign was a success; in 2007 virtually no one was searching for "chocolate diamonds", and in 2014 the number jumped to 400,000 times a year. Diamonds occur in various colors, including blue, yellow, green, orange, various shades of pink and red, brown, gray and black. Before

3828-477: The reversible reduction of protons to H 2 . Nickel(II) forms compounds with all common anions, including sulfide , sulfate , carbonate, hydroxide, carboxylates, and halides. Nickel(II) sulfate is produced in large amounts by dissolving nickel metal or oxides in sulfuric acid , forming both a hexa- and heptahydrate useful for electroplating nickel. Common salts of nickel, such as chloride, nitrate, and sulfate, dissolve in water to give green solutions of

3894-464: The subsequent 5-cent pieces. This alloy proportion is not ferromagnetic . The US nickel coin contains 0.04 ounces (1.1 g) of nickel, which at the April 2007 price was worth 6.5 cents, along with 3.75 grams of copper worth about 3 cents, with a total metal value of more than 9 cents. Since the face value of a nickel is 5 cents, this made it an attractive target for melting by people wanting to sell

3960-399: The terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment . Nickel-78, with a half-life of 110 milliseconds, is believed an important isotope in supernova nucleosynthesis of elements heavier than iron. Ni, discovered in 1999, is the most proton-rich heavy element isotope known. With 28 protons and 20 neutrons , Ni is " doubly magic ", as

4026-552: The time) during non-war years from 1922 to 1981; the metal content made these coins magnetic. During the war years 1942–1945, most or all nickel was removed from Canadian and US coins to save it for making armor. Canada used 99.9% nickel from 1968 in its higher-value coins until 2000. Coins of nearly pure nickel were first used in 1881 in Switzerland. Birmingham forged nickel coins in c.  1833 for trading in Malaysia. In

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4092-415: The treatment is performed artificially, using electrons, neutrons or gamma-rays. Radiation treatment induces characteristic sharp optical absorption lines which can be easily detected by spectroscopic techniques. Synthetic diamonds created by compressing graphite to several gigapascals and heating to temperatures above 1500 °C are usually rich in nitrogen. Nitrogen in those diamonds is dispersed through

4158-592: Was brought to Thailand by the Thai Diamond Manufacturers Association to be exhibited in the Thai Board of Investment Exhibition in Laem Chabang and was selected to herald De Beer's centennial celebrations in 1988. The Golden Jubilee was purchased from De Beers by a group of Thai business people led by Henry Ho in 1995. It was arranged for the diamond to be given to King Bhumibol as a gift from

4224-462: Was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt , who initially mistook the ore for a copper mineral , in the cobalt mines of Los, Hälsingland, Sweden . The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick ). Nickel minerals can be green, like copper ores, and were known as kupfernickel – Nickel's copper – because they produced no copper. Although most nickel in

4290-451: Was hard to determine since the GIA and other third party assessors did not evaluate these diamonds. To rectify the issue, Rio Tinto created a grading system where C1 represents the lightest color and C7 the darkest. In 2000, the fine jewelry company Le Vian trademarked the term "chocolate diamond" and introduced a new brown jewelry line. Le Vian worked with the supplier Rio Tinto and partnered with

4356-429: Was patented by Ludwig Mond and has been in industrial use since before the beginning of the 20th century. In this process, nickel is treated with carbon monoxide in the presence of a sulfur catalyst at around 40–80 °C to form nickel carbonyl . In a similar reaction with iron, iron pentacarbonyl can form, though this reaction is slow. If necessary, the nickel may be separated by distillation. Dicobalt octacarbonyl

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