The History of Black Diamonds

In medieval Italy, the Black Diamond was seen as the “stone of reconciliation”. Wave a Black Diamond in the face of the spouse with whom you’ve just had a spat…and all will be well again. A rather expensive way to patch things up you may well say. I say, for those of you going to therapy…trying to work your way through things…try a Black Diamond.
Let us leave the world of myth however, and enter into a brief history of reality. The Black Orloff…also known as the “Eye of Brahma”. This stone gets its name from the Russian Princess Nadia Vyegin-Orloff who owned it during the mid-eighteenth century. It was also part of a shrine in India in the nineteenth century. It was exhibited, in the early fifties, at the American Museum of Natural History. It is the most famous of the Black Diamonds. It is a cushion shape, weighing 67.50 carats. Once owned by Harry Winston, it was sold, mounted in platinum, for $300,000.00. Later, Sotheby’s New York acquired it and sold it for around $100,000.00. Clearly, the steal of the century folks.
Amsterdam is in the Northern most part of Europe and home to the Amsterdam Diamond. This diamond is a Pear Shape stone weighing 55.85 carats and given this name in honor of the city of Amsterdam’s 700 anniversary.
And then there’s the Black Star of Africa…a 202 carat stone which is deemed to be the largest colored-diamond in the world. It was on exhibit in Tokyo in 1971 and was valued at 1.2 million dollars U.S.

Natural History of Diamonds

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When carbon or carbon bearing materials are exposed to high temperature and pressure for an extended period of time, diamonds are formed. Deep within the Earth, there are areas that are thermodynamically favorable for the formation of diamonds, due to the high temperature and pressure found in these regions. Starting approximately 90 miles under the continental crust, with a pressure of 5 gigapascals and a temperature of 1200 degrees Celsius, diamonds are formed. Diamonds tend to grow larger under oceanic crust, after long periods of exposure to the high pressures and temperatures found there. There are both inorganic and organic carbon found in diamonds. Diamonds have different names depending on the type of carbon found in them. Diamonds formed from inorganic carbon found in the Earth's mantle are called harzburgitic, whereas eclogitic diamonds are formed from organic carbon from detritus that has been pushed down from the surface of the Earth's crust. The diamonds that are brought to the surface of the Earth are older than most, ranging from 1-3.3 billion years old. Any natural, high pressure, high temperature event can cause diamonds to form. Micro-diamonds, which are very small diamonds, have been found in craters where meteors struck the earth and created areas of high temperature and pressure. These small diamonds are used to indicate sites where there was once a meteorite impact. In the oldest regions of the Earth's crust, volcanic pipes bearing diamonds can commonly be found. Volcanic pipes are found below small surface volcanic craters, and contain material that was brought towards the surface during volcanic activity, yet never erupted. The magma does not contain diamonds, yet transports the rocks and materials to the surface. Diamonds that are brought to the Earth's surface by magma in a volcanic pipe can erode out and be dispersed over a very large area. A primary source of diamonds is the term used to describe a volcanic pipe containing diamonds. A secondary source occurs where a number of diamonds accumulate due to the activity of water or weather. Diamonds have been found in glacial deposits, yet are not found in large numbers, and are not considered a potential commercial source of the gem. It is also possible for diamonds to be forced to the surface after two continental plates collide, although it is rare.

TYPES OF DIAMONDS

Pink Diamonds :

The pink diamond is the world's most rare and valuable diamond.The Argyle mine is the world's foremost source of unrivalled intense pink diamonds, producing 95% of the world's supply. However, an extremely small proportion of Argyle Diamonds production is Pink colour, in fact less than one tenth of 1% is classified Pink. The legend of Argyle pink diamond has grown over the past ten years. At the 1989 Christie's auction in New York a 3.14 carat Argyle pink sold for $1,510,000. Privately, Argyle has sold pink diamonds for up to $1 million a carat.For years the white diamond was considered the world's most beautiful diamond, until the discovery of the Argyle mine heralded the arrival of the Argyle pink diamond. Never before had pink diamonds displaying such intense shades of colour been seen. The pink diamonds of India, Brazil and Africa were characteristically light in colour and paled even further when placed beside the intensely pink Argyle diamonds. The natural colour diamonds have in fact been around as long as the classical whites but in much smaller quantities and never in great demand.The Argyle pink diamond comes in shades ranging from delicate pastel rose to robust raspberry and full-blooded purple-reds. The prices per carat are determined by the intensity of colour. Argyle selects only its most vibrant pink diamonds for polishing at its head office in Perth. There, the stones are polished in a wide range of cuts, such as round brilliant, marquise, oval and pear, to enhance their natural beauty. Polished pink diamonds are available in the same size ranges as traditional commercial sizes.Once a year, Argyle Diamonds issues a special release of outstanding pink diamonds that are sold by special bids in the international and invitation-only, Pink Diamond Tender.

White Diamonds :

White diamonds are produced by mines all over the world in a wide variety of shapes and sizes.The white diamonds recovered from the Argyle mine are particularly brilliant and of high quality.White diamonds with secondary pink colourThe Argyle mine also produces white diamonds with secondary pink colour that command a higher price per carat. In an effect similar to that described of pink champagne diamonds, the white diamond will display slight to bold flashes of pink when viewed from the top. A higher price is commanded for pink secondary colour depending on its depth and strength, because pink is one of the most rare colours found in diamonds.

Champagne Diamonds:

Champagne diamonds are naturally coloured diamonds that are produced in a wide range of colours from light straw to rich cognac.The 4C's of colour, cut, clarity and carat weight apply to coloured diamonds just as they do to colourless diamonds except the intensity of colour, not lack of it, plays a greater part in the valuation.Argyle Diamonds created the following scale specifically for champagne diamonds. The diamonds are graded on a C1-C7 colour scale. C1 and C2 represent light champagne, C3 and C4 medium champagne, and C5 and C6 dark champagne. The fancy cognac diamond is graded C7.Pink Champagne Diamonds Attractive champagne diamonds with secondary pink colour are also available and command a higher price per carat than champagne diamonds. These stones display slight to bold flashes of pink in their fire.Argyle Pink Champagne Diamonds are available in three ranges of shades, from light pink champagne to medium and dark pink champagne.As pink is one of the rarest colours found in diamonds, even secondary colours demand a higher price depending on depth and strength of colour.

Yellow Diamonds:

Fancy yellow diamonds come in a broad range of shades ranging from light yellow to a rich canary colour.A limited quantity of fancy yellow diamonds is recovered from the Argyle mine.Blue DiamondsFancy blue diamonds are available in a wide range of shades, from the blue of the sky to a more "steely" colour than sapphire.Limited quantities of fancy blue diamonds are recovered from the Argyle mine.

Green Diamonds:

Fancy green diamonds are also available. Usually, penetration of the colour is not very deep and is often removed during the fashioning of the stone.A limited quantity of fancy green diamonds is recovered from the Argyle mine.

Diamond SimulantsCubic Zirconia :

Cubic Zirconia (CZ) is the most commonly encountered diamond simulant. All commercial CZ is formed in laboratories however, it is also found in nature. In both its synthetic and natural forms, CZ is colourless but colour can be introduced. A thermal pen tester can quickly and easily detect CZ.Synthetic moissanite Synthetic moissanite is a new diamond simulant to join the long list of products that imitate diamonds. Although moissanite is being marketed as a new unique, synthetic gemstone, some of its properties are close enough to those of diamonds to lead to confusion in the trade.Natural moissanite was first identified in a meteorite crater at the beginning of the twentieth century however, most is produced synthetically as natural moissanite is very rare. Chemically, it is 'silicon carbide', also known as 'carborundum', which is widely used for abrasive purposes and for use in the electronics industry.Synthetic moissanite is a diamond simulant like Cubic Zirconia however, it can be passed as a diamond by the widely used thermal pen testers because it has similar thermal characteristics to diamonds. However, it can be easily identified by other methods.

The diamond industry

The diamond industry can be broadly separated into two basically distinct categories: one dealing with gem-grade diamonds and another for industrial-grade diamonds. While a large trade in both types of diamonds exists, the two markets act in dramatically different ways.
Gem diamond industry:Diamond (gemstone)
A large trade in gem-grade diamonds exists. Unlike precious metals such as gold or platinum, gem diamonds do not trade as a commodity: there is a substantial mark-up in the retail sale of diamonds. Contrary to popular belief, there is a well-established market for resale of polished diamonds (e.g. pawnbroking, auctions, second-hand jewellery stores, diamantaires, bourses, etc.). One hallmark of the trade in gem-quality diamonds is its remarkable concentration: wholesale trade and diamond cutting is limited to a few locations. 92% of diamond pieces cut in 2003 were in Surat, Gujarat, India.Other important centers of diamond cutting and trading are Antwerp, where the International Gemological Institute is based, London, New York, Tel Aviv, Amsterdam. A single company—De Beers—controls a significant proportion of the trade in diamonds. They are based in Johannesburg, South Africa and London, England. One contributory factor is the geological nature of diamond deposits: several large primary kimberlite-pipe mines each account for significant portions of market share (such as the Jwaneng mine in Botswana, which is a single large pit operated by De Beers that can produce between 12.5 to 15 million carats of diamonds per year, whereas secondary alluvial diamond deposits tend to be fragmented amongst many different operators because they can be dispersed over many hundreds of square kilometres (e.g. alluvial deposits in Brazil).The production and distribution of diamonds is largely consolidated in the hands of a few key players, and concentrated in traditional diamond trading centers. The most important being Antwerp, where 80% of all rough diamonds, 50% of all cut diamonds and more than 50% of all rough, cut and industrial diamonds combined are handled.[citation needed] This makes Antwerp the de facto 'world diamond capital'. New York, however, along with the rest of the United States, is where almost 80% of the world's diamonds are sold, including auction sales. Also, the largest and most unusually shaped rough diamonds end up in New York.[citation needed] The De Beers company, as the world's largest diamond miner holds a clearly dominant position in the industry, and has done so since soon after its founding in 1888 by the British imperialist Cecil Rhodes. De Beers owns or controls a significant portion of the world's rough diamond production facilities (mines) and distribution channels for gem-quality diamonds. The company and its subsidiaries own mines that produce some 40 percent of annual world diamond production. At one time it was thought over 80 percent of the world's rough diamonds passed through the Diamond Trading Company (DTC, a subsidiary of De Beers) in London, but presently the figure is estimated at less than 50 percent.The De Beers diamond advertising campaign is acknowledged as one of the most successful and innovative campaigns in history. N. W. Ayer & Son, the advertising firm retained by De Beers in the mid-20th century, succeeded in reviving the American diamond market and opened up new markets, even in countries where no diamond tradition had existed before. N.W. Ayer's multifaceted marketing campaign included product placement, advertising the diamond itself rather than the De Beers brand, and building associations with celebrities and royalty. This coordinated campaign has lasted decades and continues today; it is perhaps best captured by the slogan "a diamond is forever".Further down the supply chain, members of The World Federation of Diamond Bourses (WFDB) act as a medium for wholesale diamond exchange, trading both polished and rough diamonds. The WFDB consists of independent diamond bourses in major cutting centres such as Tel Aviv, Antwerp, Johannesburg and other cities across the USA, Europe and Asia.In 2000, the WFDB and The International Diamond Manufacturers Association established the World Diamond Council to prevent the trading of diamonds used to fund war and inhumane acts.WFDB's additional activities also include sponsoring the World Diamond Congress every two years, as well as the establishment of the International Diamond Council (IDC) to oversee diamond grading.
Industrial diamond industry:
Diamonds in an angle grinder bladeThe market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100 million carats or 20,000 kg annually), unsuitable for use as gemstones, are destined for industrial use. In addition to mined diamonds, synthetic diamonds found industrial applications almost immediately after their invention in the 1950s; another 3 billion carats (600 metric tons)[citation needed] of synthetic diamond is produced annually for industrial use. Approximately 90% of diamond grinding grit is currently of synthetic origin.The dominant industrial use of diamond is in cutting, drilling, grinding, and polishing. Most uses of diamonds in these technologies do not require large diamonds; in fact, most diamonds that are gem-quality except for their small size, can find an industrial use. Diamonds are embedded in drill tips or saw blades, or ground into a powder for use in grinding and polishing applications. Specialized applications include use in laboratories as containment for high pressure experiments (see diamond anvil cell), high-performance bearings, and limited use in specialized windows.With the continuing advances being made in the production of synthetic diamonds, future applications are beginning to become feasible. Garnering much excitement is the possible use of diamond as a semiconductor suitable to build microchips from, or the use of diamond as a heat sink in electronics.The boundary between gem-quality diamonds and industrial diamonds is poorly-defined and partly depends on market conditions (for example, if demand for polished diamonds is high, some suitable stones will be polished into low-quality or small gemstones rather than being sold for industrial use). Within the category of industrial diamonds, there is a sub-category comprising the lowest-quality, mostly opaque stones, which are known as bort or 'boart'.

Material Properties of diamond

A diamond is a transparent crystal of tetrahedrally bonded carbon atoms and crystallizes into the face centered cubic diamond lattice structure. Diamonds have been adapted for many uses because of the material's exceptional physical characteristics. Most notable are its extreme hardness, its high dispersion index, and extremely high thermal conductivity (900 – 2320 W/m K). Above 1700 °C (1973 K / 3583 °F), diamond is converted to graphite. Naturally occurring diamonds have a density ranging from 3.15 to 3.53 g/cm³, with very pure diamond typically extremely close to 3.52 g/cm³
Hardness:
Diamond is the hardest natural material known, where hardness is defined as resistance to scratching.[8] Diamond has a hardness of 10 (hardest) on Mohs scale of mineral hardness.[9] Diamond's hardness has been known since antiquity, and is the source of its name.The hardest diamonds in the world are from the Copeton and Bingara fields located in the New England area in New South Wales, Australia. They were called can-ni-fare (cannot be cut) by the Cutters in Antwerpt, when they started to arrive in quantity, from Australia in the 1870s. These diamonds are generally small, perfect to semiperfect octahedra, and are used to polish other diamonds. Their hardness is considered to be a product of the crystal growth form, which is single stage growth crystal. 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.The hardness of diamonds contributes to its suitability as 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.Industrial use of diamonds has historically been associated with their hardness; this property makes diamond the ideal material for cutting and grinding tools. As the hardest known naturally-occurring material, diamond can be used to polish, cut, or wear away any material, including other diamonds. Common industrial adaptations of this ability include diamond-tipped drill bits and saws, and the use of diamond powder as an abrasive. Less expensive industrial-grade diamonds, known as bort, with more flaws and poorer color than gems, are used for such purposes.Diamond is not suitable for machining ferrous alloys at high speeds as carbon is soluble in iron at the high temperatures created by high-speed machining, leading to greatly increased wear on diamond tools when compared to alternatives.
Electrical conductivity :
Other specialized applications also exist or are being developed, including use as semiconductors: some blue diamonds are natural semiconductors, in contrast to most other diamonds, which are excellent electrical insulators. The conductivity and blue color originate from the boron impurity. Boron substitutes for carbon atoms in 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.
Toughness :
Toughness relates to a material's ability to resist breakage from forceful impact. The toughness of natural diamond has been measured as 3.4 MN m-3/2, which is good compared to other gemstones, but poor compared to most engineering materials. As with any material, 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, prior to faceting

Blood Diamonds

Diamonds are symbols of wealth, elegance and love around the world. But in several African nations, they have been a means to power, a reason to terrorize millions of innocent civilians, and may have even helped finance some of the world's most brutal terrorists. The human cost of the illicit global diamond trade is examined in the provocative documentary. Because they are portable, easily concealed, and untraceable, diamonds lend themselves to smuggling and corruption. In several underdeveloped African nations, warlords have used diamonds to help finance wars, while the rest of the world has turned a blind eye. Rebel armies have forced tens of thousands of people to mine diamonds in brutal, dangerous conditions under the threat of death, their pay as paltry as a cup of rice per day. In Sierra Leone, rebels chopped off people's hands, arms, feet, lips, and ears indiscriminately for years during a civil war financed in part by the trade of illicit diamonds. BLOOD DIAMONDS looks to some of the world's foremost experts for the facts of the history of the diamond trade, and goes to the heart of the matter, interviewing both the victims and perpetrators of diamond-fueled atrocities in countries like Sierra Leone. One such victim is Usman Conteh. Captured by rebels in Sierra Leone's Kono district, Usman was forced to mine diamonds for rebels - diamonds the rebels then sold or traded for arms. After months in captivity, Usman escaped only to find rebels had murdered his family. The documentary explores the factors that led to the violence, tells the vivid details of the suffering, and speaks with the organizations that eventually exposed the link between diamonds and several brutal African conflicts. BLOOD DIAMONDS also looks at the steps eventually taken by advocacy organizations and the diamond industry to combat the problem.Executive Producer for The History Channel is Margaret G. Kim. BLOOD DIAMONDS is produced by Bill Brummel Productions.