Gemmology Canada - Special Issue
by Linda Crane, Winnipeg, Man.
Diamonds when they first come to mind are generally white or colourless. They are highly valued for being as white or colourless as possible. However, even more valuable, partially due to their rarity, are fancy diamonds. This refers to diamonds that come in a range of colours such as red, dark blue, pink, green, amber and canary yellow. Diamonds of a definite colour are extremely rare. Natural coloured diamonds are basically a "freak of nature". Brown [champagne/cognac], pink and red fancies are actually deformed diamonds. Defects in their crystal lattice structure change their colour. Blue and yellow diamonds have trace elements of boron and nitrogen in their makeup. While it is known which chemical processes cause colour changes, researchers are still not sure why some diamonds change colour and other diamonds do not.
Famous diamonds are almost always substantial in weight. There are a certain number of famous diamonds that are not only large but coloured as well.
A scientific explanation for the phenomenon of the green colour in green diamonds is that the colour is usually caused by the crystal coming in contact with a radioactive source at some moment during its geological formation. The most common form of irradiation encountered by diamonds is by the alpha particles which are present in magma or kimberlite in minute quantities. Prolonged exposure to these particles creates a green spot on the surface of the diamond or a thin green coating which is only skin deep, and can be removed by polishing the stone on a scaife. Further bombardment to the stone by beta and gamma rays as well as neutrons will discolour the stone to a greater depth and in some particular cases can turn the whole of the stone's interior green. Green diamonds of this nature are very unique. The change in colour is due to the altering of the crystal's lattice structure. Before the bombardment by radioactive particles the crystal's lattice was stable but the initial radioactive shock was enough to upset the equilibrium and produce a green discolouration in the stone.
Heating the stone may sometimes improve its colour but care must be taken to keep the temperature below 600 Celsius because at this critical temperature the green colour is liable to turn to a light yellow or brown. It is clear to see why a natural green untreated diamond would be very valuable indeed. Imagine if that green diamond was pear cut and weighed 41 carats, you would then be talking about a famous fancy diamond -- The Dresden Green .
The Dresden Green derives its name from the capital of Saxony where it has been on display for more than two hundred years. The diamond was believed to have originated in the diamond mines in the district of Golconda in India. Marcus Moses an important diamond merchant of the time brought the large green diamond to London in 1726. Before the sale to the first owner, almost five years later it is believed that the Dresden Green was cut and polished in London.
In the spring of 1741 the diamond was sold to Frederick Augustus II King of Poland at the Great Annual Easter Fair at Leipzig by a Jewish merchant named Dallas for the sum of 30,000 .
The jeweller for the royal court named Dinglinger was commissioned the next year to fashion a badge of the Golden Fleece to hold the Dresden Green . Just four years after that the Golden Fleece was broken up by Genoan master goldsmith Pallard so he could create another still using the Dresden Green of course.
In 1753 the British Museum in London received a model of the Dresden Green diamond that was probably made when the stone was cut. The museum still has that model today. It is made of glass.
After the defeat of Saxony in 1768 in the Seven Years War, Pallard's fleece was dismantled by a jeweller named Diessbach from Prague. The section holding the Dresden Green was kept intact and made part of the hat ornament where it currently resides.
The diamond was allowed to be photographed and examined in great detail with an optical goniometer by Professor Roesch and Dr. Krumbhaar of Germany in 1925. During World War II the Dresden Green along with the rest of the collection of the Green Vaults was moved to safety out of Dresden. The Green Vaults had been erected on the direction of Augustus the Strong the original owner to house the collection. At the close of the Second World War, a Russian organization called the Soviet Trophies Commission took the contents of the Green Vaults to Moscow. They were returned to the city of Dresden in 1958 from the K nigstein Vaults.
A major exhibition in 1959 at the Albertinum in Dresden publicly displayed the Dresden Green for the first time since 1942. The Dresden Green and its hat ornament are now on display in the Green Vaults. It was here in 1988 that the first gemmological examination was conducted by two senior members of the Gemological Institute of America. The Dresden Green diamond was proved to be not only of extraordinary quality but also a rare type IIa, one of the purest forms of diamond. It is a large pendeloque shape of stone. The diamond is exceptionally transparent despite its considerable thickness. The clarity grade determined by G.I.A. was VS1. Because the famous green diamond can not be removed from the bezel-prong mounting without risk of damage to the historic metal work, it was with difficulty that a weight of 41 metric carats was arrived at.
Areas that were visible on the girdle ranged from extremely thin to very thin and were slightly wavy. It was remarkable actually that the symmetry was in fact good and its polish very good for a diamond cut prior to 1741. After the examination in 1988 it was determined possible to recut the Dresden Green diamond to improve its clarity perhaps even to flawless without a significant weight loss. However, while this would never be done to such a historic diamond it is a measure of the superior quality of this stone.
Diamonds with green skins or scattered green patches (radiation stains) are common. Faceted diamonds with a natural green body colour like the Dresden are extremely rare. The Dresden diamond is the most famous fancy green diamond.
A major famous or perhaps infamous fancy blue coloured diamond in public view today is the Hope
. It is renown for its striking violet blue colour and its fascinating history of bringing bad luck to its private owners.
A French diamond merchant named Jean Tavernier who travelled the Orient for jewels for Louis XIV showed the diamond to the King in 1668 after returning from his sixth trip to India. It was first cut Indian style and weighed 112.50 carats. Five years after the king bought it, he had the royal goldsmith cut it into the shape of a heart. The diamond was called the Royal French Blue
. In 1774 Louis XVI inherited it and Marie Antoinette wore it.
When the revolution broke out the heart cut blue diamond while under guard in the French Treasure House -- Garde Meuble was stolen. It was never seen again! The Royal French Blue
was believed to be sold in Spain and there cut into three smaller stones. The Goya portrait of Queen Marie Louisa painted in 1799 shows her wearing a deep blue diamond cut much like the one that was offered for sale in London in 1830 now 44.5 carats of rounded oval
A French diamond merchant named Jean Tavernier who travelled the Orient for jewels for Louis XIV showed the diamond to the King in 1668 after returning from his sixth trip to India. It was first cut Indian style and weighed 112.50 carats. Five years after the king bought it, he had the royal goldsmith cut it into the shape of a heart. The diamond was called the Royal French Blue . In 1774 Louis XVI inherited it and Marie Antoinette wore it.
When the revolution broke out the heart cut blue diamond while under guard in the French Treasure House -- Garde Meuble was stolen. It was never seen again! The Royal French Blue was believed to be sold in Spain and there cut into three smaller stones. The Goya portrait of Queen Marie Louisa painted in 1799 shows her wearing a deep blue diamond cut much like the one that was offered for sale in London in 1830 now 44.5 carats of rounded oval
Henry Phillip Hope a wealthy banker bought the diamond for $90,000. It was after that the diamond took on its now still existing name "The Hope Diamond ." It stayed in the Hope family until the turn of the century and the legend of its sinister influence began again.
It was recalled that Montespan the mistress of Louis XIV lost her place in court soon after wearing it. Louis XIV died a miserable death of smallpox. Louis XVI who inherited it, and Marie Antoinette who wore it were both executed. The Hopes themselves added to the stories. The original Henry Hope died without marrying, leaving the stone to his nephew. The stone was then passed on to a grandson who changed his surname to Hope to inherit it. Unfortunately bad luck plagued him, and his wife ran off with another man.
The last of the Hopes went bankrupt and the stone was sold to a jeweller. It changed hands frequently in the next few years. A Folies star who wore it was killed by a jealous lover. A Greek broker who bought it fell off a cliff with his wife and children. The Sultan of Turkey, Selim Habib, was forced to sell it when faced with a revolution. It was put up for auction in Paris in 1909 but no one bought it. Shortly after that, C. H. Rouseau purchased it only to resell it the same year to Cartier, the French jeweller.
It was at Cartier's that Mr. Edward B. McLean and his wife found it. He was the son of millionaire publisher John R. McLean. Edward and his new bride each had $100,000 from their respective fathers as a wedding gift. Two hundred thousand dollars was exactly the price Cartier wanted for the Hope . Mrs. McLean was not able to take it at that time, as her husband did not want to put his half of the money. One year later Cartier arrived in Washington with it reset in a necklace, Mrs. McLean raised $154,000 to buy it from him.
She loved it, there was no doubt of that. Their son was killed in an automobile accident, their daughter died of an overdose of sleeping pills and Mr. McLean suffered a nervous breakdown and died in a mental hospital. But while gossip said the Hope was their undoing, Mrs. McLean placed no stock in legends about her diamond. She wore it constantly and stuffed it into a cushion when she didn't. Mrs. McLean hired a detective as a body guard to stand by on all occasions so she would not be robbed. At one point she pawned it to help the Lindbergh Baby, but the man she aided was the imposter Gastor Means. Mrs. McLean died in 1947, a legend in her own time. The Hope Diamond was bought by Harry Winston along with other jewels in her estate for more than $1,000,000. He first displayed it in his Fifth Avenue salon. After putting it on display at various charity shows, he mailed it to the Smithsonian Institution. The stamps cost him $145.00, $2.44 postage and the rest for insurance of $1,000,000. The Hope Diamond hangs in the case there today and is one of the most popular displays at the Smithsonian. It is probably seen by more people each year than any other diamond.
Although, the Hope has been in the United States for most of the 20th century since its purchase in 1911 by Evalyn Walsh McLean it had never been formally graded. In December 1988 the opportunity presented itself when GIA learned that the Hope was being removed from its mounting for a number of reasons including photography and the making of a model. Several representatives of the New York office of the GIA travelled to Washington to prepare a complete grading report on the Hope . After the stone was unmounted and weighed, it was 45.52 carats rather than the previously published weight of 44.50 carats.
It is classified IIB diamond, which are semiconductive and usually phosphoresce. The Hope Diamond phosphoresces a strong red colour, which will last for several seconds after exposure to short wave ultra-violet light. The diamonds blue colouration is attributed to trace amounts of boron in the stone. When examined by the GIA they observed that the gem showed evidence of wear. Its clarity is slightly affected by a whitish graining which is common to blue diamonds. They described the colour as a fancy dark grayish blue.
The diamond has left the Smithsonian only three times since it was donated. In 1962 it was exhibited for a month at the Louvre in Paris, France as part of an exhibit entitled Ten Centuries of French Jewellery. In 1965 the Hope diamond travelled to South Africa where it was exhibited at the Rand Easter Show in Johannesburg. In 1984 the diamond was lent to Harry Winston Inc., in New York, as part of the firm's 50th anniversary celebration. After that it has been residing in the same case at the Smithsonian Institute where it is enjoyed by many new people every day.
A vivid yellow diamond is a rare occurrence. Absorption in yellow diamonds is caused by nitrogen rather than one of the usual transition elements. The Tiffany is the largest yellow diamond in existence. The 287.42 carat crystal was found in the historic DeBeers Mine, South Africa in 1887.
Tiffany & Co., the famous Fifth Avenue jewellery firm after which the stone is named bought it the following year. Tiffany had the yellow diamond cut in Paris under the supervision of Dr. George Frederick Kunz, the company's distinguished gemologist. It has ninety facets: forty on the crown and forty-eight on the pavilion, plus a table and a culet.
Strangely enough eighty years were to pass after its discovery before the beautiful canary yellow diamond was in a piece of jewellery.
More than twenty-five million people are estimated to have seen the great gem in four large expositions: the Chicago Columbian Exposition in 1893, the Pan American Exposition in 1901. The Chicago Century of Progress exposition in 1933-34 and the New York World's Fair in 1939-40. In the latter, it was the highlight of the fourteen million dollar collection in the "House of Jewels." The diamond has been on almost continuous display through the years at Tiffany's.
The Tiffany diamond was mounted in a necklace and worn for the first time as a personal ornament at the Tiffany Ball in Newport in 1957. The honour of this first wearing went to the Ball's chairwoman, Mrs. Sheldon Whitehouse.
It was mounted for the occasion in a necklace of white diamonds. In 1971 the Tiffany returned to South Africa for the exhibition which marked the centennial celebration of the Kimberley Mine. After an absence of forty years from London, Tiffany's re-opened their branch in Old Bond Street in 1986 and displayed the diamond to herald their return.
The sole hiatus in the otherwise uneventful history of the Tiffany has centred on reported attempts to sell the diamond which was valued at $12,000,000 at the end of 1983. In 1951 the new chairman of Tiffany's recommended that the gem should be sold. This decision horrified some members of the old Board. A buyer agreed to pay $500,000 for the stone but the deal fell through because the chairman wanted a cheque in full whereas the prospective buyer wished for other financial arrangements to be made.
Then in 1973 the New York Times carried an advertisement by Tiffany's, offering to sell the diamond for $5,000,000. However, in the circumstances it would be as well to recall the story of the eager new salesman who, when he asked what would he get if he sold the famous gem, was promptly told by the head of the firm "Fired". The Tiffany to this day is still displayed for all to see at Tiffany's Fifth Avenue, New York.
Diamonds also come in red, lilac, pink, black and brown:
The Halphen Red diamond is one of particular interest among diamonds of unusual colour, those of a red hue are extremely rare. Edwin Streeter, a diamond dealer in the 19th century in Paris bought one that was just a carat, which subsequently he sold for 800 . It was known as the Halphen Red . It was an extraordinary deep ruby red colour. There are other red diamonds that are as large as 5 metric carats, but the colour of the Halphen Red is unmatched.
The Hortensia [Hydrangea] diamond a 20 carat five-sided stone of fine pink colour was originally purchased by Tavernier in India and sold to Louis XIV in 1669. After the French Revolution, it was one of the stones reserved from the sale of the French Crown Jewels in 1883.
Tiros Lilac -- Found in Tiros district, Minas Gervais, Brazil, 1938. Lilac coloured and weighing 12.25 carats. Location today not known.
Earth Star -- A 111.59 carat coffee brown pear shape was cut from a 248.90 carat rough, found in Jagersfontein Mine, South Africa, in 1967. It is thought to be the largest brown diamond in the world.
Fine fancy stones are always rare, but in this market, rareness is relative. For example, brown stones are the most common colour, and for that reason they are also the least expensive. Fine yellows, on the other hand, are rarer than browns, although compared to some of the other stones, they are downright plentiful. Pinks and blues are probably the rarest of all the regularly traded fancy coloured diamonds. The supply of pink stones picked up when Australia's Argyle mine came on stream in 1986. Most of these are smaller stones, larger fine pinks are still in short supply. Fine blues are just as rare.
There are also red and green diamonds, but these are so impossible to find dealers donít really consider them a stable category.
Coloured diamonds are increasingly being sought after in the market today not only for their beauty but for their investment value. Overseas customers in particular would much rather have a coloured diamond of great distinction rather than property, stocks or bonds.
It is safe to say that coloured diamonds are not just a trend in the jewellery trade but that they are here to stay.
Balfour, Ian.  Famous diamonds, 2nd ed. Santa Monica, California : Gemological Institute of America. 245 p.
Bates, Rob.  "Jewelers take a fancy to colored diamonds." National Jeweler , Vol. 39, no. 4, pp. 30-31.
Bruton, Eric.  Diamonds, 2nd ed. Radnor, Pennsylvania : Chilton Book Co. 532 p.
Copeland, Lawrence L. and Jeanne G. M. Martin.  Diamonds... famous, notable and unique, 1st ed. Santa Monica, California : Gemological Institute of America. 204 p.
Crowningshield, Robert.  "Grading the Hope diamond." Gems and Gemology , Vol. 25, no. 2, pp. 91- 94.
Dickinson, Joan Younger.  The book of diamonds: their history and romance from ancient India to modern times, New York, New York : Crown Publishers, Inc. 226 p.
Encyclopedia Smithsonian,  Available at Hope diamond
Jackson, James O.  "Are diamonds still forever?" Time , Vol. 147, no. 10. pp. 58-62.
Kane, Robert E., Shane F. McClure and Joachim Menzhausen.  "The legendary Dresden Green diamond." Gems and Gemology , Vol. 26, no. 4, pp. 248-266.
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