Posts Tagged ‘diamond’
Colour
Posted on: October 11, 2011
Colour
Ideally, a diamond should have no colour at all, like a drop of spring water. Increasing degrees of body colour are measured on a scale ranging from no colour at all (D) to deeply coloured (Z). Beyond “Z” is the range where the diamond’s colour is vivid and rich, called “fancy colours”. Diamonds of known colour are used as comparison stones for colour grading. Grading is done by comparing the diamond to be graded against these “master stones” under either artificial or natural north daylight ( in the Northern Hemisphere). A machine called the “Colorimeter” can be used for colour grading but there is no substitute for the trained human eye. The color of a diamond may be affected by chemical impurities and structural defects in the crystall lattice. Depending on the hue and intensity of a diamond’s coloration, a diamond’s color can either detract from or enhance its value. For example, most white diamonds are discounted in price when more yellow hue is detectable, while intense pink or blue diamonds can be dramatically more valuable. Out of all colored diamonds, red diamonds are the rarest. The Aurora Pyramid of Hope displays a spectacular array of naturally colored diamonds, including red diamonds. Diamonds occur in a variety of colors — steel gray, white, blue, yellow, orange, red, green, pink to purple, brown, and black, virtually in every color of the rainbow. Colored diamonds contain interstitial impurities or structural defects that cause the coloration, whilst pure diamonds are perfectly transparent and colorless. Diamonds are scientifically classed into two main types and several subtypes, according to the nature of impurities present and how these impurities affect light absorption: Type I diamonds have nitrogen atoms as the main impurity, commonly at a concentration of 0.1%. If the nitrogen atoms are in pairs they do not affect the diamond’s color; these are Type IaA. If the nitrogen atoms are in large even-numbered aggregates they impart a yellow to brown tint (Type IaB). About 98% of gem diamonds are type Ia, and most of these are a mixture of IaA and IaB material: these diamonds belong to the Cape series, named after the diamond-rich region formerly known as Cape Province in South Africa, whose deposits are largely Type Ia. If the nitrogen atoms are dispersed throughout the crystal in isolated sites (not paired or grouped), they give the stone an intense yellow or occasionally brown tint (Type Ib); the rare canary diamonds belong to this type, which represents only 0.1% of known natural diamonds. Synthetic diamond containing nitrogen is Type Ib. Type I diamonds absorb in both the infrared and ultraviolet region. They also have a characteristic fluorescence and visible absorption spectrum . Type II diamonds have no measurable nitrogen impurities. Type II diamonds absorb in a different region of the infrared, and transmit in the ultraviolet below 225 nm, unlike Type I diamonds. They also have differing fluorescence characteristics, but no discernible visible absorption spectrum. Type IIa diamond can be colored pink, red, or brown due to structural anomalies arising through plastic deformation during crystal growth—these diamonds are rare (1.8% of gem diamonds), but constitute a large percentage of Australian production. Type IIb diamonds, which account for 0.1% of gem diamonds, are usually light blue due to scattered boron within the crystal matrix; these diamonds are also semiconductors, unlike other diamond types (see Electrical properties of diamond). However, a blue-grey color may also occur in Type Ia diamonds and be unrelated to boron. Also not restricted to type are green diamonds, whose color is derived from exposure to varying quantities of radiation
The majority of diamonds that are mined are in a range of pale yellow or brown color that is termed the normal color range. Diamonds that are of intense yellow or brown, or any other color are called fancy color diamonds. Diamonds that are of the very highest purity are totally colorless, and appear a bright white. The degree to which diamonds exhibit body color is one of the four value factors by which diamonds are assessed.
Grading fancy color diamonds
Yellow or brown color diamonds having color more intense than “Z”, as well as diamonds exhibiting color other than yellow or brown are considered fancy colored diamonds. These diamonds are graded using separate systems which indicate the characteristics of the color, and not just its presence. These color grading systems are more similar to those used for other colored gemstones, such as ruby, sapphire, or emerald, than they are to the system used for white diamonds.
Diamonds that enter the Gemological Institute of America’s scale are valued according to their clarity and color. For example, a “D” or “E” rated diamond (both grades are considered colorless) is much more valuable than an “R” or “Y” rated diamond (light yellow or brown). This is due to two effects: high-color diamonds are rarer, limiting supply; and the bright white appearance of high-color diamonds is more desired by consumers, increasing demand. Poor color is usually not enough to eliminate the use of diamond as a gemstone: If other gemological characteristics of a stone are good, a low-color diamond can remain more valuable as a gem diamond than an industrial-use diamond, and can see use in diamond jewelry.
Value:
Diamonds that go out of scale in the rating are known as “fancy color” diamonds. Any light shade of diamond other than light yellow or light brown automatically falls out of the scale. For instance, a pale blue diamond won’t get a “G” or “K” color grade, it will get a Faint Blue or Light Blue grade. These diamonds are valued using different criteria than those used for regular diamonds. When the color is rare, the more intensely colored a diamond is, the more valuable it becomes. Another factor that affects the value of Fancy-Colored diamonds is fashion trends. For example, pink diamonds fetched higher prices after Jennifer Lopez received a pink diamond engagement ring.[citation needed] Extremely low grade quality has not stopped creative merchants, such as Le Vian, from marketing Dark Brown diamonds as so-called “Chocolate Diamonds”.
Fancy-colored diamonds such as the deep blue Hope Diamond are among the most valuable and sought-after diamonds in the world. In 2009 a 7-carat (1.4 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 (US$9.5 million at the time) which is in excess of US$1.3 million per carat.
Shah Diamond
Posted on: October 9, 2011
The Diamond Shah is 88.7 carat (18 g), 3 cm long, yellow diamond, extremely clear. This diamond was found in Central India, probably in 1450.
This fine stone shares with the “Jehan-Ghir Shah” the honour of being the only diamonds that are known to have ever been engraved in the East. And so little known are even these specimens, that they are not so much as mentioned by King in his otherwise interesting account of diamond engraving in the Natural History of Precious Stones.
The “Shah” seems to have formed part of the Persian regalia from the remotest times. Barbot asserts that it was lost when Nadir Shah’s treasures were plundered by his revolting troops after his death in 1747. But if so, it was afterwards recovered, for according to the generally accepted account, it was presented to the Russian Emperor, Nicholas I., by the Persian Prince Cosrhoes, younger son of Abbas Mirza, when he visited St. Petersburg in 1843.
Characteristics:
The “Shah” is table-cut, or what is technically known as lasque. It is of the very finest water, without the least cloud or flaw, and so pure throughout, that in treating it, the cutter was able to leave several of the national facets untouched. This circumstance also explains the small sacrifice which it suffered in the process of reduction. It is said to have weighed in the rough about 95 carats, and as its present weight is 86 carats, it lost 9 carats only in the cutter’s hands. The three facets obtained by cleavage are beautifully engraved in Arabo-Persian characters with the names of three Persian rulers as under:
1. (Akbar Shah).
2. (Nisim Shah).
3. (Fat’hh Ali Shah).
Round the upper edge of the stone runs a small groove, apparently for the purpose of securing the string with which it was worn suspended round the neck. By what process this intaglio and the inscriptions were executed it is impossible to say. The probability is that all were done at the same time by some European gem-engraver employed by the Persian Court.
The third name engraved on this remarkable diamond is that of Aga Mohammed’s nephew, who succeeded him in 1797. On Aga’s death in that year, the usurper, Sadek Khan seized a great quantity of crown jewels. But he was defeated at Kasvin, and he purchased his freedom by surrendering most of these treasures. The rest he retained, intending, if necessary, to use them in a similar way on some future occasion. Some time afterwards he did actually again revolt. Fat’hh Ali’s patience was now exhausted, and he not only confiscated all the remaining jewels, amongst which was this engraved stone, but also ordered the rebel Sadek Khan to be bricked up alive in a dungeon. This method of punishment was adopted because Fat’hh Ali had, on a former occasion, promised on oath never to shed Sadek’s blood.
Yet Fat’hh Ali, in spite of his inhuman punishment of Sadek, was not naturally cruel. Many instances are, indeed, related of his kindly and magnanimous disposition. On one occasion, as he was passing through the desert from Bastam to Shahrud, it so happened that the ladies of the harem and their escort lost their way. The king, with a few attendants, immediately set out in search of them; but they strayed so far that all the water was consumed and nothing remained except a small piece of ice, which was reserved for Fat’hh Ali. Perceiving however, that a young prince had fainted from weakness and thirst, this Oriental Sir Philip Sydney relinquished the life-giving morsel, and with his own hands placed it in the mouth of his exhausted fellow traveller.
Fat’hh Ali was on one occasion visited by Sir R. Kerr-Porter, who in his Travels thus describes his magnificent reception: “He entered the saloon from the left, and advanced to the foot of it with an air and step which belonged entirely to a sovereign. Had there been any assumption in his manner I could not have been so impressed. He was one blaze of jewels, which literally dazzled the sight on first looking at him. A lofty tiara of three elevations was on his head, which shape appears to have been long peculiar to the crown of the great king. It was entirely composed of thickly-set diamonds and pearls, rubies and emeralds, so exquisitely disposed as to form a mixture of the most beautiful colours in the brilliant light reflected from its surface. Several black feathers like the heron’s plumes, were inter-mixed with the resplendent aigrettes of this truly Imperial diadem, whose bending points were finished with pear-shaped pearls of an immense size. The vesture was of gold tissue, nearly covered with a similar disposition of jewelry, and crossing the shoulders were too strings of pearls, probably the largest in the world. I call his dress a vesture, because it set close to his person, from the neck to the bottom of the waist, showing a shape as noble as his air. At that point it devolved downwards in loose drapery, like the usual Persian garment, and was of the same costly materials with the vest. But for splendour nothing could exceed the broad bracelets round his arms, and the belt which encircled his waist. They actually blazed like fire, when the rays of the sun met them; and when we know the names derived from such excessive lustre, we cannot be surprised at seeing such an effect. The jewelled band on the right arm was called the ‘Mountain of Light,’ and that on the left ‘the Sea of Light.’ These names were of course derived from the celebrated diamonds contained in the bracelets.”
It will be seen from our account of the “Darya-i-Nur” and “Moon of Mountains” that this writer is in error regarding the name of one of these famous diamonds. His description is in other respects extremely interesting, and helps to show that towards the beginning of the present century most of the crown jewels (scattered during the troubles ensuing on the death of Nadir Shah), had again been recovered and collected in the royal treasury.
Fat’hh Ali, who retained his seat on the throne till his death in 1834, was remarkable in another respect. His harem consisted of 800 ladies, and he left issue nearly two hundred children. Mr. Binning assures us that in 1850, many of his off-spring were still alive, and earning their bread as artisans and tradesmen.
Facts:
It was rendered to the shah court in Ahmadnagar. In 1591, Shah Nizam ordered carving on one of the facets of the diamond: “Burhan-Nizam-Shah Second. Year 1000″.
In the same 1591, the ruler of the Northern India, the Great Moghul Akbar, occupied Ahmadnagar and seized the diamond. After Akbar’s grandson, Shah Jehan (trans. “the king of the world”) came to the throne of Great Moghuls, he commanded to carve another inscription: “The son of Jehangir-Shah Jehan-Shah. Year 1051”. By the modern calendar, it was 1641. The son of Jehan-shahAureng-Zeb hung the diamond above his throne and encircled it with rubies and emeralds. Till1738, the diamond Shah was kept in Delhi.
In 1738, Nadir Shah attacked India, seized the diamond, and took it back with him to Persia. In1824, the third inscription appeared on the third facet: “The ruler of the Kadgar-Fath ali-shah Sultan. Year 1242”.
In 1829, Russian diplomat and writer Alexandr Griboyedov was murdered in the capital of Persia, Tehran. The Russian government demanded severe punishment of those responsible. In fear, the court of Shah Fath Ali Shah sent the Shah’s grandson Khosrow Mirza to Saint Petersburg, where he gave the Shah diamond to the Russian Tsar as a present
In 1914, the Shah diamond came to the Kremlin Diamond Fund, where it is exhibited as one of Seven Historical Gems.
It remains there at the Kremlin.
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Christie’s New York will hold its Magnificent Jewels sale on October 18, offering 340 lots that together carry a presale estimate of $35 million. The October sale in New York marks the official opening of Christie’s fall season globally, which includes major sales of important jewels in Geneva, Paris, London and Hong Kong before returning to New York for the grand finale auction of the season: The collection of Elizabeth Taylor in December.
”As we meet with collectors and dealers around the world in the run-up to this autumn season, it is clear that demand for rare and important jewelry remains as strong as ever,” said Rahul Kadakia, the head of jewelry for Christie’s Americas. ”Recent top prices for colored and colorless diamonds and gemstones have helped bring some spectacular jewels into the marketplace, including top-quality D-color diamonds and some truly exceptional fancy colored diamonds in shades of yellow, pink, blue and green.”
The top lot of the New York sale is a 32.77 carat, vivid yellow diamond, pictured, with a golden yellow hue so intense and so deep that the Gemological Institute of America (GIA) ranks it amongst the rarest of gemstones in its class. It carries a presale estimate of $6 million to $8 million.
The sale also features fancy colored diamonds in shades of pink, blue and green, including a 3.21 carat, pear-shaped, fancy vivid blue diamond ring, flanked by side diamonds, and it has a presale estimate of $2.5 million to $3 million. The sale includes an 8.20 carat, pear-shaped fancy purplish-pink diamond ring by Tiffany & Co. and it carries a presale estimate of $1.25 million to $1.8 million.
Christie’s offers six large D-color diamonds along with a broad assortment of fine diamond necklaces, earrings, brooches and bracelets. The largest of the D-color diamonds is a 25.74 carat, oval-cut diamond ring by Graff that is estimated at $3.5 million to $5 million.
(information from official Rapaport website)
The Blue Hope
Posted on: September 19, 2011
A dark, steely blue stone from India, the diamond eventually named the Hope is more notorious than any other diamond. It was originally purchased by a French merchant traveler, who sold it to King Louis XIV in 1668. Set in gold and suspended on a neck ribbon, the king wore the “Blue Diamond of the Crown” or “French Blue” on ceremonial occasions. During the French Revolution in 1792, when Louis XVI and Marie Antoinette attempted to flee France, the French Blue was stolen.
Evidence suggests that it was acquired in the early 1800s by King George IV of England, and likely sold at his death in 1830 to help pay off his debts. The diamond was subsequently purchased by Henry Philip Hope, from whom it takes its name. While in the possession of the Hope family, the diamond acquired its grim reputation for bad luck: The entire Hope family died in poverty.
Henry Thomas Hope’s possession of the diamond was uneventful. However, one of his heirs who came to own it, Lord Francis Hope, was in financial difficulties due to a penchant for gambling. After numerous attempts (and despite the opposition of other family members) he finally succeeded in selling the Hope diamond in 1901. The diamond was purchased by a New York diamond merchant, Simon Frankel. At this point, the diamond was said to be involved in several bizarre events, although none have been substantiated.
First, a French broker by the name of Jacques Colot was said to have bought the stone before becoming insane and committing suicide. Next, a Russian or Eastern European prince, Ivan Kanitowsky, supposedly loaned or gave the diamond to an actress at the Folies Bergêre, who was shot the first time she wore it. The prince himself was stabbed to death by revolutionaries. A Greek jeweler who sold the diamond to the Sultan of Turkey was thrown over a cliff while riding in a car with his wife and child. Again, it is difficult to separate the fact and fiction.
It is known that after several owners, the Hope diamond was sold by Cartier’s to Mrs. Evalyn Walsh McLean of Washington, D.C. Some researchers believe it was Pierre Cartier who popularized the story that the stone brought misfortune to its owners – and anyone who touched it.
Mrs. McLean was the daughter of Thomas F. Walsh, who amassed a fortune in gold mining. She spent her early childhood in mining camps in Colorado and South Dakota, but was later educated in Washington D.C. and in Europe. She married Edward Beale McLean, son of the owner of the Cincinnati Enquirer and the Washington Post.
Although Mrs. McLean refused to believe in the legendary Hope “curse” she also endured a number of family tragedies. Her brother died young; her nine-year-old son was run over by a car and killed; her ex-husband drank heavily and died in a mental institution; and her only daughter died of a drug overdose at age 25. Mrs. McLean never recovered from the latter tragedy, and passed away only a year later. Upon her death, Mrs. McLean’s extensive jewelry collection was purchased by Harry Winston Inc. of New York City. After exhibiting it among other notable gems for the next 10 years, the firm donated it to the Smithsonian Institution, where it remains one of its premier attractions.
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