Sunday, August 9, 2009

Diamonds in China - 701 Changma diamond mine

Diamonds in China - 701 Changma diamond mine

Many people don't know that China has diamond mine and for quite a long time as China's 701 Changma diamond mine was opened in 1975. China has produced about 300,000 carats in 2002 and their diamond industry looks to be having great potential despite some problems.701 Changma diamond mine is the largest producer of diamonds in China and is located in the Shandong province.

In its more than 30 years of existence this diamond mine produced over 1 Mct of quality diamonds.Some other provinces are also being explored beside Shandong province (Liaoning, Anhui, Jiangsu and Shaanxi Provinces) as China is well aware of high profits in diamond business and wants to become major player on diamond market.Production in Changma diamond mine increased significantly in last couple of years and considering the findings of new kimberlite pipes in some provinces China is on the right way to become major diamond force in years to come.

Not only China is the large diamond producer but is also among top five consumers of diamond jewelry with and this is increasing because of China's rapid economic growth.Despite China's great potential in diamond industry, China is still not complete certainty for profits in diamond business, since excessive management, external costs, corruption and lack of reliability prevented China's full diamond industry development.

There's also influential underground economy, but with the wise government policy China could and really should benefit from its big potential, as both producer and consumer of diamonds.

Diamonds in South Africa - Venetia diamond mine



South Africa has its first diamonds discovered in 1867, when diamonds were discovered near Kimberley. and this rich diamond source secured South Africa's number one spot as the world's leading diamonds producer in the mid-twentieth century.


Famous De Beers company was also founded in Kimberley (known also as "Diamond city") as Cecil Rhodes founded this well known company in 1888. De Beers is still the most influential diamond force in South Africa.


In 2003 South Africa produced above 11 Mct of diamonds. the most important mine is Venetia Diamond mine in the Limpopo province in South Africa, which is famous for producing some of the best quality diamonds in the world since its opening in 1992. Venetia Diamond mine alone produced in 2005 almost 7,2 Mct of diamonds and it employs about 1000 people. This is also first mine in the world to achieve ISO 9002 quality management certification. This is open-pit mine that is expected to carry on for the next 20 years.

South Africa is also home of prestigious Diamond Education College which provides internationally recognized diplomas and trains its students in rough and polished diamond evaluation and rough diamond marking.

Diamonds in Russia - Sakha Republic diamonds



Russia is world's second largest producer of diamonds just behind Botswana and accounts for about 21% of global diamonds produced. When speaking about Russian diamonds, three regions take special place: the Arkhangelsk region, Perm region and the Sakha/Yakutsk Republic. Most diamonds are mined in Sakha Respublikata in Yakut (Yakutia) of Siberia, just below the Arctic circle.


Yakutsk is the capital city of the Sakha Republic (Yakutia) and this area is not only filled with diamonds but also with gold and oil. Sakha Republic is place where major Russian producers operate large open-pit mines on the Udachnaya and Jubilee kimberlite pipes.


Udachnaya mine ("udachnaya" meaning lucky) is the largest diamond deposit in Russia and has produced very high quantity of big diamonds (for instance a 301 ct diamond was recovered in August 2003). This mine is also producing by number of experts, world's clearest diamonds.


Jubilee mine started its work in 1986 and it is open pit mine just as Udachnaya mine. This mine is constructed over the 'Yubileinaya' kimberlite pipe.

Anabar mine is also located in Sakha Republic but harsh weather conditions (most northern of all Russian mines) cause this mine to operate just during the short summer season.


Siberia certainly holds many more diamond deposits which just wait to be discovered so Russia's diamond future looks to be very bright and Russia has even potential (considering huge area this country covers) to overtake number one spot from Botswana in years to come.



Red diamonds - Rarest of them all



Among fancy colored diamonds red diamonds have special place, not only because these these diamonds are among most desirable diamonds, but also because they are extremely rare, so rare that many jewelers have never seen one of this really unique diamonds. Out of all colored diamonds red diamonds are the rarest of them all.


When saying extremely rare that doesn't only apply to natural red diamonds as it is also very difficult to find even enhanced red diamonds, so you can imagine how precious red diamonds really are. So even if you have plenty of money finding natural red diamond will be more than difficult.


Natural red diamonds are mostly found at Argyle mine in Australia, though in very limited number which has tremendous impact on their price which is in most cases astronomical. The biggest red diamond ever found is known under the name of "Red Shield" and has only 5,11 carats which is more than hundred times less than largest diamonds of any kind. Another famous red diamond was "Hancock Red" that for its weight of 0,95 carats was sold for incredible price of $880,000 at Christie's New York in April, 1987.


Red diamonds are really elite among fancy colored diamonds, and only few lucky (and extremely wealthy) people have luck to buy these unique diamonds. Many other are forced to look for alternatives in different color, or rubies which are much more affordable.

Diamonds in Brazil - Long history of diamonds



Brazil is the second country (after India) in which diamonds were found (that happened in 1725). In these early years Brazil was still very much behind India, but as the Indian diamonds dried up, Brazil took the first place throughout the 19th century leading the world diamond production till 1870.

The most famous diamond found in Brazil is "Star of the South," a 254 carat stone that was found in 1854. Brazilian diamonds occur usually in alluvial deposits that were created by Diamantiferous sands and gravel called "cascalho" or "cascalhão".

Brazilian diamond industry is mostly connected with these two states: Matto Grosso and Bahia and these two diamond rich states should also provide future diamond findings as Brazilian diamond industry still looks very strong despite relatively early discovery of diamonds.

Brazil's currently holding 10th place in the world with total annual production in 2005 of about 700,000 carats.

Friday, August 7, 2009

Diamond Geology

Diamond Geology

Kimberlite Pipes

Diamonds form at a depth greater than 93 miles (150 kilometers) beneath the earth's surface. After their formation, diamonds are carried to the surface of the earth by volcanic activity. A mixture of magma (molten rock), minerals, rock fragments, and occasionally diamonds form pipes shaped like champagne flute glasses as they approach the earth's surface. These pipes are called kimberlites (see diagram below). Kimberlite pipes can lie directly underneath shallow lakes formed in the inactive volcanic calderas or craters.


Kimberlite is a diamondiferous igneous-rock matrix composed of carbonate, garnet, olivine, phlogopite, pyroxene, serpentine, and upper mantle rock, with a variety of trace minerals. Kimberlite occurs in the zone of the Earth's crust in vertical structures known as kimberlite pipes (above, right). Kimberlites are found as "dikes" and "volcanic pipes" which underlie and are the source for rare and relatively small volcanoes or "maars" (above, left). Kimberlite pipes are the most significant source of diamonds, yet only about 1 in every 200 kimberlite pipes contain gem-quality diamonds. Many kimberlite pipes also produce alluvial diamond placer deposits.

Diamond bearing kimberlite in some parts of South Africa is black in color (above, right). Most kimberlite is called "blue-ground" kimberlite (above, left) or "yellow-ground" kimberlite and can be found worldwide. The name "Kimberlite" was derived from the South African town of Kimberly where the first diamonds were found in this type of rock conglomeration (see section on "Kimberley - North Cape" below).

Lamproite Pipes


Lamproite pipes produce diamonds to a lesser extent than kimberlite pipes. Lamproite pipes are created in a similar manner to kimberlite pipes, except that boiling water and volatile compounds contained in the magma act corrosively on the overlying rock, resulting in a broader cone of eviscerated rock at the surface. This results in a martini-glass shaped diamondiferous deposit as opposed to kimberlite's champagne flute shape.

Alluvial (Placer) Diamonds


The location of alluvial (secondary or placer) diamond deposits is controlled by the surrounding topography. Alluvial diamond deposits are usually located within river terrace gravels that have been transported from their location of origin, usually from kimberlite deposits.
Diamondiferous material tends to concentrate in and around 'oxbow lakes,' which are created by abandoned river meanders. These dried 'lakes' receive river water during seasonal flooding which transports large amounts of sediment held in suspension.
The alluvial terrace gravels (below, left) and marine gravels of the south-western coastline of Africa represent the some of the world's largest placer diamond deposits. The world's largest known gem quality alluvial diamond deposits are located along the Namib Desert coastline of southwestern Africa, known as the Sperrgebiet or "forbidden territory," and along the Orange River near Alexander Bay. Namibia's placer diamond deposits are between 40 and 80 million years old, carried from their primary origination point on the Kaapvaal Craton, in central South Africa and Botswana.



Alluvial diamond mining in Angola takes place along a meandering stretch of the Cuango River flood-plain which is also along the south-western coastline of Africa. Some of the largest and highest gem-quality diamonds produced from alluvial placer diamond mining have come from this region, including Angola's two largest diamonds at 105.9k and 101.8k.
Many of these alluvial diamond deposits occur in Pleistocene and Holocene successions (1.8 million to 10,000 years ago). The diamonds within these deposits were transported from deeply-eroded diamondiferous kimberlites or, to a lesser extent, from olivine lamproites formed during the Cretaceous or Permo-Triassic period. Westward draining river systems transported these diamonds to Africa's continental coastline for final deposition within on-shore marine terrace gravels. Diamonds that were transported downstream, but were not deposited on land, made their way to the sea bed just offshore. Diamonds in marine areas are typically trapped in bedrock depressions such as gullies, potholes, depressions, channels or other trapsites for diamondiferous deposits.


Artisanal Mining

Artisanal diamond mining (aka "small-scale mining") involves nothing more that digging and sifting through mud or gravel river-bank alluvial deposits (above, right) with bare hands, shovels, or large conical sieves. Laborers who work in artisanal diamond mining are called "diamond diggers" (below left). Artisanal diamond mining is a form of "subsistence based" non-mechanized mining that is used in poorer countries throughout the world.

Artisanal diamond mining is used throughout west Africa, in conflict zones where mechanized mining is impractical and unsafe. Artisanal diamond mining accounts for 90% of Sierra Leone's diamond exports and is the country's second largest employer after subsistence farming. It is also used extensivly in Angola, the Congo (DROC), and Liberia.


Saturday, August 1, 2009

Diamond Mines of the World | Botswana

Diamond Mines of the World Botswana

Botswanan Diamond Mines

Jwaneng Diamond Mine

Jwaneng (meaning "a place of small stones") is the richest diamond mine in the world when measured by value of recovered diamonds. The Jwaneng Diamond Mine is located in south-central Botswana about 100 miles west of the city of Gaborone, in the Naledi river valley of the Kalahari Desert. The mine began operations in 1982, and is co-owned by De Beers and the Botswanan government under the name 'Debswana Diamond Company.'

Jwaneng is an open pit mine dug over three kimberlite pipes that converge near the surface. The mine has a very high extraction rate, producing 9.3 million tons of kimberlite ore per year at a ratio of 1.25 carats of diamond per ton. In 2003, the mine produced 14.3 million carats of rough, high-quality diamonds. As of 2005, known reserves will produce at current levels for 27 more years. The Jwaneng mine employs over 2,100 workers.
Jwaneng is the first Botswanan to receive ISO 14001 certification for environmental compliance and has maintained a 5 star NOSA safety rating since 1986. The mine has won multiple national and international safety awards since its inception.
Botswana is a relatively wealthy African country, and has had one of the fastest per-capita income growth rates in the world. Botswana gained its independence in 1966 and has had strong ties to the economy of South Africa for several decades. Botswana's history of diamond mining is commemorated on the 20 and 100 Pula bank notes (below).
There are three additional diamond mines of significance in Botswana. The Lethakane Mine ("little reeds") open pit mine is the second oldest of Botswana's four mines. The Orapa Mine ("resting place for lions") open-pit mine is the oldest of Botswana's mines, located along the 'Orapa Kimberlite Track,' near the boarder with Zimbabwe. The Damtshaa Mine ("water for a tortoise") open pit mine is the other significant mine in Botswana.

AK6 Diamond Mine
De Beers is expecting to have Botswana's first new diamond mine in nearly 26 years, operational by 2008. The AK6 kimberlite deposit is expected to produce up to 1.5 million carats a year.

Friday, July 24, 2009

The Briolette of India Diamond




The Briolette of India Diamond


The Briolette of India is a legendary diamond of 90.38 carats, which, if the fables about it are true, may be the oldest diamond on record, perhaps older than the Koh-I-Noor Diamond. In the 12th century, Eleanor of Aquitaine, the first Queen of France and later England, brought the stone to England. Her son, Richard the Lionhearted, is said to have taken it on the Third Crusade. It next appeared in the 16th century when Henry II of France gave it to his blonde mistress, Diane de Poitiers. It was shown in one of many portraits of her while at Fontainebleau.








Harry Winston examining the Briolette of India with a jeweler's loupe.After disappearing for four centuries, the stone surfaced again in 1950 when the jeweler, Harry Winston, of New York, bought it from an Indian Maharajah. It was sold to Mrs. I.W. Killam and bought back by Mr. Winston, following her death, about 10 years later. In 1970, Mr. Winston showed the stone at the Diamond Dinner for American Fashion Editors. Source: Diamonds - Famous, Notable and Unique (GIA)








The Briolette of India set in a necklace with a diamond a large pearl.The book Diamonds - Famous, Notable and Unique was published in 1974, since that time new information on the Briolette of India has surfaced. The gem was thought to have a history extending to the Middle Ages, unfortunately recent research has revealed it was cut in Paris in 1908-9. Nevertheless, the gem is very unique and remains the most famous briolette-cut diamond in the world.

The Conde Diamond

The Conde Diamond
The Grand Conde is one of the most unusual of the world's notable diamonds: a light pink pear-shaped stone of 9.01 carats. Agents of Louis XIII are said to have bought the stone in 1643 after which the King presented it to Louis de Bourbon, Prince of Conde, who had distinguished himself as Commander of the French Army in the Thirty Years' War and who became known as the Grand Conde. Until his death in 1686, the Prince was known as an enthusiastic patron of the arts and an ardent admirer of various charming women, one of whom described him as a much more effective and able general than paramour! The diamond remained in the Conde family until the Duc d'Aumale bequeathed it to the French Government in 1892. Today, it is on display in the Musee de Conde in Chantilly, France, where according to the terms of the Duc's will, it must always remain. On October 11th, 1926, the diamond was stolen from the museum but later found and returned. It is also known variously as the Conde Pink, the Conde Diamond, or Le Grand Conde.


A glass replica of the Conde.
Many sources have quoted this gem as weighing around 50 carats, which is false. The gem's actual weight is 9.01 carats, and however the 50-carat statement got started is still unknown, but I'd imagine its something like a gemologist probably wrote a book a hundred years ago and mistook the stone for a different one. When following authors/gemologists went to research the stone, they came across the 50-carat figure and repeated it, thus starting a cycle. Special thanks to Greg Thompson of the Texas Faceters Guild for varifying the stone's actual weight! I had already seen both figures being quoted as its weight and was baffled at the figures being so drastically different!


Thursday, July 23, 2009

The Centenary Diamond


The Centenary Diamond

The diamond Jubilee of De Beers Consolidated Mines passed off quietly in 1948, the massive post-WWII growth and expansion of the diamond industry had barely begun, while several important sources of diamonds, including the Premier Mine, were still closed, while others remained to be discovered. Forty years later the annual output of diamonds exceeded 100 million carats and sales of rough diamonds reached around $5 billion. On March 11th, 1988, the centenary celebrations of De Beers took place in Kimberly and a banquet was held to close the Kimberly Mine (aka the "Big Hole"). An audience of four hundred people, including representatives of several national governments of diamond-producing countries and dignitaries from various sections of the industry, listened to the welcoming speech of the chairman, Julian Oglivie Thompson, totally unprepared for his final sentence: "We have recovered at the Premier Mine a diamond of 599 carats which is perfect in color - indeed it is one of the largest top-color diamonds ever found. Naturally it will be called the Centenary Diamond."


The Centenary, appearing to be lit by multi-colored lights. No more fitting way of celebrating 100 years of achievement by De Beers could have been devise than the discovery of such a diamond and nowhere was it more likely to have been recovered than at the Premier Mine. Over the years this extraordinary mine has produced several outstanding diamonds of the most superb color, which have been cut into famous gems: The Cullinan in 1905; the Niarchos in 1954; the Taylor-Burton in 1966 and the Premier Rose in 1978. Now that the second millennium has ended, it is interesting to reflect that only nineteen gem-quality diamonds larger than the Centenary rough have been found during its course. The Premier Mine itself has produced nearly three hundred stones weighing more than 100 carats, and a quarter of the world's diamonds weighing more than 400 carats. The Centenary was found on July 17th, 1986 by the electric X-ray recovery system at the Premier Mine. Only a handful of people knew about it and all were sworn to silence. In its rough form it resembled an irregular matchbox with angular planes, a prominent elongated "horn" jutting out at one corner and a deep concave on the largest flat surface. The shape of the stone expressed problems in cutting with no apparent solution. The man chosen to evaluate the Centenary was Gabi Tolkowsky, famed in the diamond industry as one of the most accomplished cutters in the world. His family had long been in the diamond trade and it was his great-uncle, Marcel Tolkowsky, diamond expert and mathematician, who published a book in 1919 titled "Diamond Design", which for the first time set out exact ways of cutting the modern round brilliant cut. Gabi Tolkowsky himself was the creator of five new diamond cuts, revealed in 1988, which concentrate on maximizing brilliance, color or yield - or a combination of all three from off-color rough diamonds previously thought difficult to cut profitably into conventional round or fancy shapes. Named for flowers, the cuts are largely based on unorthadox angle dimensions. The overall proportions as well as the use of more facets around the pavilion increase brilliance and improve visual impact when viewed face-up.

Gabi Tolkowsky examines the Centenary with a jeweler's loupe.A good photo to show you how massive this diamond is. :) When he first saw the Centenary, Tolkowsky was astounded by its exceptional purity. "Usually you have to look into a diamond to appreciate its color, but this just expressed itself from its surface. That is very rare," Tolkowsky said. He knew the protruding "horn" would have to be removed as well as other "asperities," as he called them, which interfered with the stone's basic shape. At the same time, Tolkowsky realized that the diamond would be difficult to polish because its shape did not offer an obvious approach. Usually a diamond will suggest two or three shapes to its cutter but the Centenary was more generous - if more baffling - by providing several possibilities. In the end Tolkowsky submitted his appraisal, saying that the diamond must be kept intact to produce one singe large modern-cut diamond. He was asked to cut the Centenary, and late in 1988 Tolkowsky, two master cutters - Geoff Woolett and Jim Nash - together with a handpicked group of engineers, electricians and security guards set to work in a specially designed underground room in the De Beers Diamond Research Laboratory in Johannesburg, South Africa. It was crucial that the room, like the special tools needed for faceting, should be stable and strong; nothing must rattle, everything must be tight, there should be no mechanical vibration or variation in temperature around the cutting table. For one whole year while the right tools and technical conditions were created, the Centenary remained unaltered and untouched. Tolkowsky examined the stone until he knew every fissure and crevice of it. Using the most sophisticated electronic instruments he gazed deep into the crystal structure. "From the moment I knew I was going to cut it," he said, "I became another man. A strange man. I was looking at the stone in the day, and the stone was looking at me at night."

A picture of the Centenary in the hand of some unknown hand model. Another good photo to show scale. :) The first step before the diamond could be faceted was the elimination of large cracks from the edge of the stone running a considerable depth inside it. He decided not to saw or cut with a laser because both methods would heat or vibrate the diamond. Instead, he turned to the time-honored method of kerfing by hand. It took Tolkowsky 154 days to remove about 50 carats which otherwise would have been polished to dust. At the end was a roughly-shaped rounded crystal about the size of a bantam's egg, weighing about 520 carats. After that was an endless process of drawing and measuring as possible shape designs began to emerge. In all, thirteen different designs were presented to the De Beers board, with the strong recommendation they should chose a modified heart shape. Once this recommendation had been accepted, the final process of faceting the Centenary began in March, 1990. By January, 1991 it was nearing completion. When cutting was completed the Centenary weighed 273.85 carats, measured 39.90 × 50.50 × 24.55 mm, and had 247 facets - 164 on the stone and 83 around its girdle. Never before had such a high number of facets been polished onto a diamond. In addition, two flawless pear shapes weighing 1.47 and 1.14 carats were cut from the rough. Amoung top-color diamonds the Centenary is surpassed only by the Cullinan I (aka the Star of Africa) and the Cullinan II, which were cut from the Cullinan crystal before modern symmetrical cuts were fully developed in the 1920's, making the Centenary the largest modern fancy cut diamond in the world and the only one to combine the oldest methods - such as kerfing - with the most sophisticated modern technology in cutting. The Cullinan diamonds are actually near-colorless, but qualify as white diamonds. The GIA color grading letters D, E and F qualify as colorless, and the Centenary is the best of the three - a 'D'. This spectacular gem, which has become the ultimate example of those qualities was shown to the world for the first time in May, 1991. Mr. Nicholas Oppenheimer, then Deputy Chairman of De Beers rightly declared "Who can put a price on such a stone?" confirming that it was insured for around $100 million. Whether the Centenary Diamond has since been sold is a mystery. The De Beers Group's policy is not to disclose such information so that the anonymity of its clients is protected. Some day the Centenary will probably resurface, perhaps at auction, or in a museum display housing some country's crown jewels. Gabi Tolkowsky has since cut another large gem of note, the Pink Sun Rise, a 29-carat pink diamond with a facet pattern similar to the Centenary's. Also cut the largest faceted diamond in the world - the Golden Jubilee. Sources: Famous Diamonds by Ian Balfour, The Nature of Diamonds by George E. Harlow, and the De Beers website. In the autumn of 2001, I found Gabi Tolkowsky's mailing address on the internet, and decided to write to him. He lives in Antwerp, Belgium, which comes as no surprise as as this is the diamond cutting capitol of the world. Among the questions I asked him was whether he had heard about the Centenary Diamond selling or not. In his reply he told me he had heard the rumor, but no one had confirmed it to him.

The Amsterdam Diamond


Msterdam Diamond

-This rare black diamond of African origin is reported to be completely black. It weighs 33.74 carats, has 145 facets and was cut from a 55.85-carat rough. The stone was first shown in February, 1973, at D. Drukker & Zn., Amsterdam. It was auctioned off at
--in November, 2001, for $352,000, setting a world record for the highest price fetched by black diamond at auction. The stone is cut in a pear shape, with horizontally split main facets on the crown.

Sunday, July 19, 2009

Nassak Diamond

Nassak Diamond

The Nassak Diamond (also known as the Nassac Diamond[2] and the Eye of the Idol[3]) is a large, 43.38 carats (8.68 g) diamond that originated as a larger diamond in the 15th century in India.[4] Found in the Amaragiri mine located in Mahbubnagar, Andhra Pradesh, India,[5] and originally cut in India, the diamond adorned the statue of Shiva in the Trimbakeshwar Shiva Temple, near Nashik, in the state of Maharashtra, India from at least 1500 to 1817.[4] The British East India Company acquired the diamond through the Third Anglo-Maratha War and sold it to British jewelers Rundell and Bridge in 1818.[4] Rundell and Bridge recut the diamond in 1818,[6] after which it made its way into the handle of the 1st Marquess of Westminster's dress sword.[4]
The Nassak Diamond was imported into the United States in 1927, and was considered one of the first 24 great diamonds of the world by 1930.[4] American jeweler Harry Winston acquired the Nassak Diamond in 1940 in Paris, France and recut it to its present flawless 43.38 carats (8.68 g) emerald cut shape.[7] Winston sold the diamond to a New York jewelry firm in 1942. Mrs. William B. Leeds of New York received the gem in 1944 as a sixth anniversary present and wore it in a ring.[7] The Nassak Diamond was last sold at an auction in New York in 1970 to Edward J. Hand, a 48-year old trucking firm executive from Greenwich, Connecticut.[8]


hitory

The Nassak Diamond originated in the 15th century in India.[4] Although the date of the original cutting is unknown, the original cutting was performed in India and had sacrificed everything to size while giving the diamond a form and appearance similar to that of the Koh-i-Noor diamond.[4][9] From at least 1500 to 1817, the Nassak Diamond adorned the statue of Shiva in the Trimbakeshwar Shiva Temple, near Nassak, India, on the upper Godavari River.[4] As priests worshiped Shiva through the statue, the diamond eventually acquired its name from its long term proximity to Nassak, India.[4]
In 1817, the British East India Company and the Maratha Empire in India began the Third Anglo-Maratha War. During the Mahratta war, the Nassak Diamond disappeared from the Shiva statue.[4] The war ended in 1818 and the British East India Company was left decisively in control of most of India.

The Nassak Diamond quickly resurfaced in the possession of Bajirao,[10] the last independent Indian Prince of Peshwa, who handed over the diamond to an English colonel named J. Briggs.[4] In turn, Briggs delivered the diamond to the Francis Rawdon-Hastings, the 1st Marquess of Hastings who had conducted the military operations against the Peshwa.[4] Rawdon-Hastings delivered the diamond to the East India Company as part of the spoils of the Mahratta war.[4] The East India Company then sent the Nassak Diamond to England, to be sold on the London diamond market in 1818.[4]
At the London diamond market, the Nassak Diamond was presented as an approximately 89 carats (18 g) diamond of great purity "but of bad form," having a somewhat pear-shape.[4] The diamond further was characterized as a "rudely-faceted, lustreless mass." Despite its appearance, the diamond was sold for about 3,000 pounds (modernly £173 thousand) to Rundell and Bridge, a British jewelry firm based in London.[4]

Rundell and Bridge held onto the diamond for the next 13 years.[4] During that time, the jewelry firm instructed its diamond cutter "to keep as closely as possible to the traces of the Hindu cutter, 'amending his defects, and accommodating the pattern to the exigencies of the subject matter.'" The recut by Rundell and Bridge from 89 3/4 carats (800 mg) to 78 5/8 carats (1,600 mg) resulted of a loss of no more than 10 percent of the original weight of the diamond.[4][11]
In 1831, Rundell and Bridge sold the diamond to the Emanuel Brothers for about 7,200 pounds (modernly £519 thousand).[4] Six years later in 1837, the Emanuel Brothers sold the Nassak Diamond at a public sale to Robert Grosvenor, the 1st Marquess of Westminster.[4] At one point, the Marquess mounted the diamond in the handle of his dress sword.[4] In 1886, the diamond was valued at between 30,000 and 40,000 pounds (modernly between £2.34 million and £3.12 million), due in part to its vast gain in brilliancy from the recut by Rundell and Bridge.[4]

The Koh-I-Noor diamond



The Koh-I-Noor diamond

It has been said that whoever owned the Koh-I-Noor ruled the world, a suitable statement for this, the most famous of all diamonds and a veritable household name in many parts of the world. Legend has suggested that the stone may date from before the time of Christ; theory indicates the possibility of its appearance in the early years of the 1300s; history proves its existence for the past two and a half centuries. The first writer has stated:


Reguarding its traditional history, which extends 5000 years further back, nothing need be said here; though it has afforded sundry imaginative writers with a subject for highly characteristic paragraphs we have no record of its having been at any time a cut stone."


The earliest authentic reference to a diamond which may have been the Koh-I-Noor is found in the Baburnama, the memoirs of Babur, the first Mogul ruler of India. Born in 1483, Babur (meaning 'lion' -- the name was not given to him at birth but appears to be a nickname, deriving from an Arabic or Persian word meaning 'lion' or 'tiger') was descended in the fifth generation from Tamerlane on the male side and in th fifteenth degree from Genghis Khan on the female side. With the blood in his veins of two of the greatest conquerors Asia has ever seen, it is not all that surprising that Babur himself should have become a great conqueror in his own right.
As a young man Babur owed his survival and success on the political and military battlefields to a combination of winning personal qualities and swift opportunism; these were to insure his conquest of the plains of northern India. But in addition to being a warrior, Babur was a cultured and civilized man - a writer and poet.


The Cullinan diamonds

The Cullinan diamonds

The Cullinan I - aka the Star of Africa. 530.20 carats.

(The stone can be removed from the Royal Scepter and worn as a pin or pendant.)
Star of Africa, a pear shaped diamond weighing 530.20 carats, aka the Cullinan I. It measures 58.9 × 45.4 × 27.7 mm, and has 76 facets (counting the culet and the table). It is called the Cullinan I because it's the largest of the 9 large stones cut from the Cullinan Diamond, and the Cullinan II is the massive 317.40-carat cushion shaped diamond in the center-front of the Imperial State Crown of Great Britain. The Crown also features the Black Prince's Ruby, as well as St. Edward's Sapphire, and the Stuart Sapphire. All the stones in the crown seem to have a history. The Star of Africa holds the place of 2nd largest cut diamond in the world and is on display with the other Crown Jewels in the Tower of London.



The nine largest pieces of the Cullinan Diamond. The largest piece would of course be cut into the Cullinan I (530.20 carats)and the the next largest into the Cullinan II (317.40 carats), and so on. This photo was probably taken in 1908, the yearafter the Cullinan rough was presented to King Edward VII for his 66th birthday.



Late one afternoon in 1905, Mr. Frederick Wells, the superintendent of the prolific Premier Mine in South Africa, was making a routine inspection trip through the mine when his attention was attracted by something reflecting the last slanting rays of the setting sun. Curious, he stopped for a closer look. He was eighteen feet below the surface of the earth, and the shiny object was on the steep wall of the mine a few feet above him. Mr. Wells quickly scaled the wall and extracted from the blueground what appeared to be a large diamond crystal. At first, he thought he was being fooled by a large piece of glass, but tests proved it to be the largest gem-quality diamond ever discovered. It weighed 3106 carats, or about 1⅓ pounds. It was named after Sir Thomas Cullinan, who opened the mine and was visiting on that eventful day. Many diamond experts believe that the huge stone was only a fragment, and that another piece, (possibly as large or even larger) either still exists and awaits discovery, or was crushed in the mining process. The latter is very unlikely. The prospect of finding the portion of the Cullinan has added zest to the activities of numerous miners and prospectors. The Cullinan was sold to the Transvaal government, which presented it to King Edward VII on his 66th birthday on November 9th, 1907. It was insured for $1,250,000 when it was sent to England. The King entrusted the cutting of the stone to the famous Asscher's Diamond Co. in Amsterdam, which had cut the Excelsior and other large gems. The huge diamond was studied for months. On February 10th, 1908, Mr. Asscher placed the steel cleaver's blade in a previously prepared V-shaped groove and tapped it once with a heavy steel rod. The blade broke, but the diamond remained intact! The second time, it fell apart exactly as planned, and an employee at the factory reported that Mr. Asscher had fainted. A second cleavage in the same direction produced three principal sections; these in turn would produce nine major gems, 96 smaller brilliants, and 9.50 carats of unpolished pieces. The nine larger stones remain either in the British Crown Jewels or in the personal possession of the Royal Family. These historically celebrated gems and their present mountings are as follows: The Cullinan I, also known as the Star of Africa, weighs 530.20 carats. King Edward placed it in the Sovereign's Royal Sceptre as part of the Crown Jewels, and it is now on display in the tower of London. The Cullinan II is a 317.40 carat cushion cut stone mounted in the band of the Imperial State Crown, it is also in the Tower of London as part of the Crown Jewels. The Cullinan III is a pear-shaped diamond weighing 94.40 carats, and is in the finial of Queen Mary's Crown and can be worn with the IV as a pendant-brooch. Many of Queen Mary's portraits show her wearing these two stones, and Elizabeth II makes use of them the same way. The Cullinan IV, a 63.60-carat cushion shape, was originally set in the band of Queen Mary's crown, but can also be worn as jewelry, as described above. The Cullinan V is a triangular-pear cut weighing 18.80 carats, was originally mounted in a brooch for Queen Mary, to be worn alternately in the circlet of her crown as a replacement for the Koh-i-Noor. This was after the Koh-i-Noor was removed to the new crown that was made for Elizabeth (now the Queen Mother) in 1937.





The Cullinan VI, an 11.50 carat marquise-cut stone, was originally presented by King Edward to his wife, Queen Alexandra, and is now worn by Elizabeth II as a drop on a diamond and emerald necklace. It was worn more frequently by the young Queen than any other section of the Cullinan. The Cullinan VII is an 8.80 carat marquise-cut stone mounted in a pendant on a small all-diamond brooch, in the center of which is the 6.80-carat cushion cut Cullinan VIII, and lastly, the Cullinan IX, a 4.39 carat pear shape, is mounted in a ring with a prong setting that was made for Queen Mary; it too is sometimes worn by Queen Elizabeth.


Elizabeth II's Imperial State Crown of Great Britain

Imperial State Crown: originally made for Queen Victoria's coronation in 1838, it was remade for George VI in 1937. It contains the 317.40 carat Cullinan II. The large stone above the Cullinan II is the Black Prince's Ruby, which is actually a red spinel. The stone was at one time a giant bead. Note the red dot on the upper part of the stone - that is a ruby that was used to plug a small hole that went right through the stone. The Stuart Sapphire is a very fine 104-carat oval shaped sapphire that appears on the backside of the crown. It was amoung the Crown Jewels of Charles II. The sapphire in the center of the cross on the top of the crown is St. Edward's Sapphire, (believed to have belonged to Edward the Confessor), and the four large drop-shaped pearls are said to have been Elizabeth I's earrings.



The Cullinan II Diamond. Note the two tiny platinum loops on the edges.This is so the stone can be worn as a brooch, alone or with the Cullinan I attached. However, it usually resides in the front of the Imperial State Crown.





St. Edward's Sapphire, from the top of the Imperial State Crown. Photo © HMSO, London
The Black Prince's Ruby on the front of the Imperial State Crown, a name which is misleading because the stone is actually a red spinel weighing about 170 carats. The gem is a large bead - the lighter-colored dot on the front of the stone is actually a ruby plugging up the hole that goes through the stone.

The Dresden Green diamonds

The Dresden Green diamonds

In the rough, greenish diamonds tend to occur as one of three types: a stone, often a crystal shape, possessing a light tinge rather like the color of water in a swimming pool; a stone with a dark green skin; a yellowish-green stone characterized by a degree if lubricity. After being cut and polished, diamonds of the first and second types usually lose their greenish color to become white gems or, alternatively, light yellow stones known as "silvery capes". The few truly green faceted diamonds therefore originate from the third type. The famous collection of De Beers Fancy Colored Diamonds, which has been displayed throughtout the world includes some beautiful examples of green diamonds



Since this is the story of a truly rare gem, a scientific explanation for the phenomenom of green diamonds is needed. The green color is usually caused by the crystal's coming into contact with a radioactive source at some point during its lifetime, and in geological terms, this is measured in millions of years. The most common form of irradiation diamonds chance into is through bombardment by alpha particles which are present in uranium compounds or percolating groundwater. Long exposure to these particles forms a green spot on the surface of the diamond, or sometimes produces a thin green coating which is only skin deep and can easily be removed during the faceting process. But bombardment by beta and gamma rays well as neutrons will color the stone to a greater depth and in some cases turn the whole stone's interior green.


Heating the stone might sometimes improve the color but care must be taken to keep the temperature below 600°C, because at this temperature the green color is likely to turn to a light yellow or brown. The change in color is caused by the change in the crystal's lattice structure. Before bombardment by radioactive particles the crystal's lattice was stable but the initial radioactive shock was sufficient to disturb the equilibrium and produce a green coloration. Tempering will distort the lattice further abd produce another change of color. This phenomena is analogous to a piece of elastic that has been overstretched; it will stretch back so far, but never returns to its original length. Similarly, after a treatment the diamond's lattice remains permanently distorted.




The Dresden Green out of its setting.
Research has disclosed that green or irradiated diamonds are more common from alluvial deposits, although they are found in primary sources, usually in the upper part of the diamond-bearing volanic pipe, but green diamonds of any size are rare. The Dresden Green, which probably weighed over 100 (old) carats in its rough form, is unique amoung world famous diamonds. It was originally probably an elongated unbroken stone since greenish diamonds rarely occur as cleavages.


The Dresden Green gets its name from the capitol of Saxony where it has been on display for more than 200 years. The earliest known reference to its existence occurs in The Post Boy, a London new-sheet of the 1700's. The issue dated October 25th - 27th, 1722 included this article:



"On Tuesday last, in the afternoon, one Mr. Marcus Moses, lately arrived from India, had the honor to wait on his Majesty [King George I (ruled 1714-27)] with his large diamond, which is of a fine emerald green colour, and was with his Majesty near an hour. His Majesty was very much pleased with the sight thereof. It is said there never was seen the like in Europe before, being free from any defect in the world; and he has shown his Majesty several other fine large diamonds, the like of which 'tis said were never brought from India before. He was also, the 25th, to wait on their Royal Highnesses with his large diamond; and they were surprised to see one of such largeness, and of such a fine emerald color without the help of a foil under it. We hear the gentlemen values it at £10,000."


Marcus Moses was an important diamond merchant in London during the first part of the 18th century - he had once been involved with the regent diamonds

Another early reference to the Dresden Green is found in a letter dated from 1726, from Baron Gautier, the "assessor" at the Geheimes Rath's Collegium in Dresden, to the Polish ambassador in London, which speaks of the green diamond being being offered to Frederick Augustus I (1694-1753) by a London merchant for £30,000. This ruler, known as Augustus the Strong, was responsible for the construction of some great buildings in Dresden, which he duly filled with great collections of rare and expensive treasures - sculptures, paintings, and objets d'art. He accumulated a collection of crown jewelsas the ruler of Saxony, and when he was elected to the throne of Poland in 1697 he commanded new regalia be made for his coronation. Frederick Augustus set aside a group of rooms in Dresden Castle to house his collection of jewels and other treasures, and named them the Green Vault, their interior decoration being trusted to Persian designers. The final result was considered to be one of the finest examples of Baroque. Nowadays, the contents of the Green Vault is housed in a contemporary Albertinium Museum, built on the site of the original castle that was destroyed during World War II.

A model of the green diamond was owned by the eminent physicist Sir Hans Sloane (1660-1753), whose collection of books, manuscripts and curiosities formed the basis of the British Museum. When Sloane retired from active work in 1741 his library and cabinet of curiosities had grown to be of unique value and on his death he bequeathed his collection to the nation, on the condition that Parliament pay his executors £20,000. The bequest was accepted and went to help form the British Museum, opened to the public in 1759.


Neither George I nor Frederick Augustus I purchased the green diamond; instead it was the latter's son, Frederick Augustus II (1733-1763) who became its first royal owner. He bought the Dresden Green from a Dutch merchant named Delles, at the Leipzig Fair in 1741. Various figures are given for the purchase price but the most interesting was found in a letter to Frederick the Great, King of Prussia (1712-1786), which states that "For the seige of Brünn the King of Poland was asked for heavy artillery. He refused due to the scarcity of money; he had just spent 400,000 thaler for a large green diamond." On orders of Frederick Augustus II, the court jeweller, Dinglinger, set the diamond in the Decoration of the Golden Fleece, but this setting lasted for only four years and was broken up in 1746. The king then commissioned the goldsmith Pallard in Vienna, to design another Golden Fleece incorporating both the Dresden Green and the Dresden White, a cushion-shaped diamond weighing 49.71 carats.

The Golden Fleece ornament with the Dresden White (top). The center third of the ornament which encompasses the Dresden Green was saved from disassembly and remains part of the present ornament. The top part of the ornament encompassing the Dresden White was saved and is now part of the Dresden White's ornament (see photo below).

From 1756 to 1763 during the continued hostilities of the Seven Years War, the contents of the Green Vault were removed for safety to the fortress of Königstein, located in southeast Dresden by the Elba River. Several years after the war, which saw the defeat of Saxony, Pallard's Golden Fleece ornament was also broken up. In 1768 another jeweller, Diessbach, worked the green diamond into a hat clasp along with two other white brilliants, weighing almost 40 carats total, and a number of smaller diamonds. The Dresden Green survives in Diessbach's ornament today.
The Dresden Green ornament on display in the Green Vault among other pieces of regalia.The white diamond ornament to the left of it contains the Dresden White Diamond at its top.
In 1806 Saxony became a kingdom and the royal line continued until 1918 when the last king abdicated. The contents of the Green Vault remained on display to the public until the beginning of World War II. In 1942 they were removed again to Königstein, thus escaping the shattering air raid by the Allied Forces on the night of February 13th, 1945 which devasted Dresden. Later that same year the Soviet Trophies Commission, which had made its headquarters in Pillnitz Castle near the center of the ruined city, took the contents of the Green Vault to Moscow, the Crown jewels being among the first items to travel there. They were returned in 1958.


The Dresden Green's facet layout, captured from its Gemcad file. This design originally appeared in the winter, 1990 issue of Gems & Gemology, and was converted into Gemcad by Robert Strickland in 1998.

The Gemmological Institute of America examined the stone in 1988. The Dresden Green Diamond was proved to be not only of extraordinary quality, but also a rare type IIa diamond. The clarity grade determined by GIA was VS1 and the gem has the potential of being internally flawless. (This means that the stone's flaws are near the outer surface, probably the pavilion of the stone, where a slight re-cutting could remove them and improve the clarity of the stone.) The gem measures 29.75 × 19.88 × 10.29mm. Unbelievably, the GIA graded the symmetry good and the polish very good. This is amazing for a diamond cut prior to 1741. Also, the Dresden Green has a natural green body color. This is extremely rare. Diamonds with green skins or scattered green patches are more common.

Another photo of the Dresden Green, photographedfrom the underside with the culet facing outward.


In the summer of 2000, Ronald Winston completed arrangements for the Dresden Green to be exhibited in October, 2000, in the Harry Winston Gallery at the Smithsonian Institution, alongside the world's most famous diamond – the Hope. The 40.70-carat Dresden Green – the largest and finest natural green diamond ever found, has long been considered a "sister" to the Hope Diamond, which it closely matches in size, intensity of color, and historical importance. Friday, October 14th, marked the official public opening of this remarkable exhibition.
It was the twelve-year quest of Ronald Winston to bring these two diamonds together. "There is only one other diamond, the Dresden Green, which comes close to the Hope Diamond in rarity and uniqueness," said Ronald Winston. "I always hoped that in my lifetime I would be able to witness the Hope Diamond and the Dresden Green on exhibit together. This would have been the crown in my father's 'Court of Jewels,' an unparalleled collection which toured the country in the 1950's and included some of the most famous diamonds in history."


The Dresden Green remained at the Smithsonian until January of 2001, when it returned the Albertinium Museum in Dresden, where it remains to this day. Sources: The Harry Winston website, Famous Diamonds by Ian Balfour, The Nature of Diamonds by George E. Harlow, the Gemstone Forecaster.

Thursday, July 16, 2009

THE AUSTRALIAN DIAMOND INDUSTRY



THE AUSTRALIAN DIAMOND INDUSTRY
Australian Argyle Diamonds are internationally reowned for their unique brilliance and stunning array of colours. Unearthed in the rugged Kimberley region in the far north of Western Australia, Argyle Diamonds thrill in shades of exotic pink, sparkling champagne, rich cognac and dazzling white.




From the rare pink diamond to the classic white and natural champagnes, Argyle Diamonds are firing the world's imagination. And why shouldn't they? The Argyle Diamond Mine is the world's biggest producer of natural diamonds and contributes approximately one-third of the world's natural supply.

Discovery Of The Argyle Diamond Mine


The Argyle diamond story has its origins in the early 1970s, when one of the world's most significant find of diamonds was made at Smoke Creek in the remote north of Western Australia, over 2000 kilometres from Perth, the state capital.

Although significant, it is certainly not the first discovery of diamonds in Western Australia. Diamonds had been recovered in the Pilbara region as far back as the 1890s but the primary source of any of these diamond finds had never been located.


The key was time and patience. For decades, geologists had known that a major source of diamonds existed in Australia, but is wasn't until 1972 that their work had identified the Kimberley region as being the most likely location. A joint venture was formed. Geologists spend the next seven years patiently searching the region to discover the Argyle diamond deposit, tantalised by new clues and frustrated by dead ends.

The geologists received their biggest encouragement yet with the Ellendale Prospect in 1977. A number of diamond-bearing kimberlite pipes were discovered in Ellendale, located near Derby. However, the evaluation of the Ellendale Prospect showed it to be uneconomical.


It wasn't until October 2 1979, that geologists were literally standing on top of the richest diamond deposit in the world. They had pinpointed the Argyle Diamond pipe.


The discovery was made while working in Smoke Creek near the awesome Lake Argyle, a man-made dam covering some 720 square kilometres. Geologists found several stones in the creek bed and back tracked along the course finding more diamonds as they went until they climbed high into the range and before long were standing on the Argyle diamond pipe.

What followed was an exclusive programme of drilling, sampling and evaluation. In 1982 the joint venture partners decided to develop a mining operation.

The Argyle Diamond Mine




In 1983, construction work began on the main open-cut mine and process plant. In the meantime, diamonds began to be recovered by an alluvial plant at Smoke Creek and Limestone Creek. Some 15 million carats of alluvial diamonds had been recovered by the time the main Argyle plant was commissioned in 1985.

Argyle Diamond Production




The Argyle diamond mine has firmly placed Australia on the top as the world's biggest producer of diamonds in terms of volume. As well as being Australia's only major diamond producer, the Argyle diamond mine is also one of the most technologically advanced mines in the world.

Since its inception, annual production has steadily increased from 29 million carats in 1986, the mine's first full year of production, to 40.9 million carats in 1993. The average annual production since 1994 has been over 35 million carats.




Every year the Argyle diamond mine is responsible for producing more than a third of the world's total annual supply of diamonds. The average annual production now totals over 35 million carats.
The Argyle diamond mine yields approximately 45 per cent near gem quality, and 50 per cent industrial quality diamonds. The remaining 5 per cent is made up of gem quality diamonds and yields the rare and highly valued pink diamonds, as well as the range of sparkling champagne and rich cognac diamonds.


Argyle Diamond Mining


The Argyle diamond mine covers an area of 45 hectares. The diamonds are recovered from the main pipe as well as from, to a lesser extent, alluvial deposits in nearby Smoke and Limestone Creeks.

The Argyle diamond pipe is a linear body, 1600 metres along and varying in width from 150 to 600 metres. In addition to being the world's biggest diamond producer and only reliable supply of intense pink diamonds, the Argyle diamond mine is unique in a third way: the diamonds are recovered from a host rock call lamproite, not kimberlite which is the traditional host
Argyle's pipe mining operation involves the removal of the diamond-bearing lamproite ore by open-cut mining techniques. The ore is dislodged by blasting and then loaded by excavators into 120-tonne dump trucks. The ore is then transported to the processing plant where the diamonds are extracted. The processing techniques are purely physical and involve crushing, scrubbing, screening and gravity separation of the diamond-bearing ore. Final diamond recovery is achieved by the use of x-ray sorting machines. The machines can detect and remove diamond material because the diamonds fluoresce under x-ray.

No chemical treatment is included in the process with the exception of a final acid cleaning of the diamonds.

Alluvial mining was discontinued in late 1985, then resumed in 1989. The diamonds recovered are included in the mine's overall annual production.


The rough diamonds are transported to Perth for sorting and sale.




Argyle Diamonds

Argyle Diamonds fall into three main categories: pink, champagne, and white diamonds. The 4C's guide to quality and value applies to coloured diamonds just as it does to white diamonds. However, coloured diamonds are graded for their intensity of colour, not lack of it.
Argyle diamonds have two very unique and outstanding features: they are harder than other diamonds and may fluoresce blue under ultra-violet light.

The hardness factor of Argyle diamonds results from its unusual atomic structure. Although all diamonds share the same atomic structure, the atoms of Argyle diamonds are bonded together in more complex arrangements. This complex structure is also one of more the major reasons for the deep colours of the Argyle product mix, especially the champagne and pink diamonds.

Around 70 per cent of the Argyle yield fluoresces blue under ultra-violet light; a day with high U.V levels will make an Argyle diamond dance and dazzle with lovely blue flashes!





The huge diamond shipments from the Argyle Mine are sorted at the Western Australian capital of Perth, the headquarters of Argyle Diamonds. The modern cutting and polishing facility is also located here however, only top quality gems from the mine are polished at this facility.


Diamond Sorting Upon reaching Perth, the rough diamonds are sorted. In order to deal with the huge volume of diamonds, Argyle Diamonds has developed new technology. Sorting begins mechanically: the first size sorting of rough diamonds takes place through a series of mechanical sieves.



However, final valuation of the diamonds can only be made by the human eye despite these advances in technology. Each individual stone is examined by diamond sorters who base their decision on clarity, size, shape and colour. Argyle retains its best quality gems for cutting and polishing.







Diamond Polishing


Argyle Diamonds carefully selects the best quality diamonds for polishing within Australia or by overseas cutting centres.



Australian Production


Argyle Diamonds began polishing diamonds in 1984. Its Perth processing centre is the first of its kind in Australia.



Australian production is staffed by highly-trained crafts-people who employ a combination of traditional methods and modern equipment to unlock the brilliance of rough stones. Argyle uses advanced technology in the form of laser devices, automatic bruting and computerised polishing equipment.



The polished stones are then sold in Australia, through a network of exclusive Australian jewellers, as well as overseas through Argyle's representative offices in Antwerp, Belgium and Bombay, India.

Overseas Production


Argyle Diamonds also sends a proportion of its rough diamonds, especially those in smaller sizes, overseas for polishing.




DIAMONDS AS AN INVESTMENT

DIAMONDS AS AN INVESTMENT


Customers when deciding to purchase diamond jewellery will often ask whether it is a good investment. In actual fact, jewellery should never be purchased for investment reasons, only for its beauty. The appeal of diamonds lies in their dazzling beauty and endurance, and their ability to provide a lasting memento of a special occasion.


Although diamond jewellery is usually bought for emotional reasons, the value of the diamond content will appreciate in time. Unlike some other commodities, the prices of diamonds have remained stable over the years. As the cost of living rises, so does the average price of diamonds. Diamonds will purchase the same now as they did last year, five years ago, or twenty years ago. Diamonds have lasting value.

Caring for your Diamonds

CARING FOR YOUR DIAMONDS

Diamonds need caring to keep them looking at their brilliant best. They should be cleaned at least once a month to keep away the "dullness" that can be caused by skin oils, soap, cosmetics and even cooking grease. The only substance that does not stick to a diamond is water. A clean diamond will reflect better light.

There are several ways of keeping diamond jewellery clean.

The detergent bath is performed with a small bowl of warm suds using any mild liquid detergent. Immerse jewellery pieces in the suds and brush gently with a tooth brush. Rinse under warm running water and pat dry with a soft, lint-free cloth.

The quick dip method uses one of the liquid jewellery care products available. Follow the instructions on the kit.

The latest jewellery-cleaning device is the sonic jewellery cleaner. It is electronically operated and comes with its own solution and directions.

Some extra helpful hints to keep diamond jewellery looking at its best.

It is better not to wear diamond jewellery when doing rough work or the dishes. Despite the durability of a diamond, it can be chipped by a hard blow along its grain.
Take care when doing the housework, not to let diamond jewellery come into contact with chlorine bleach, as it won't harm the diamond but can pit or discolour the mounting.

When placing diamond jewellery in a jewellery case, be sure to wrap them individually as they can easily scratch each other as well as other gem jewellery. Be sure to take all types of precious mounted jewellery to a jeweller at least once a year to check for loose settings and signs of wear

VALUING DIAMONDS

VALUING DIAMONDS

The quality and value of diamonds are measured by four characteristics known as the 4C's. The 4C's relate to a diamond's cut, colour, clarity and carat weight. The quality of a diamond is measured by its cut, colour and clarity. The carat weight measures the size of the diamond. Of all the 4C's, cut is the characteristic directly influenced by man; colour, clarity and carat weight are all dictated by nature.

Cut
A diamond in its natural, uncut state is described as a "rough diamond". Its natural appearance so resembles a glass pebble that most people would pass it by without a second glance. It is the skill of the diamond cutter that unlocks the brilliance for which diamonds are renowned.

If two identical diamonds are placed side by side and one is less brilliant and fiery than the other, the fault lies in the cutting. Such a stone cannot demand as high a price as a well-cut diamond.


It is important to distinguish between cut and shape. Some of the more popular shapes of diamonds include Round Brilliant, Oval, Marquise, Pear, Heart and Emerald. Within each of these shapes, however, it is the cut that determines the quality of the stone. For example, most diamonds are cut with 58 facets, regardless of their shape.

Colour

A diamond's colour is one of the most important factors in determining its value. The nearer a white diamond is to being absolutely colourless, the more rare and valuable it is. The graduations in colour are so subtle that intricate international grading scales have been devised.


Diamonds are graded into categories defined by letters. The colour range from exceptional whites (categories D, E and F) to tinted colours (categories M to Z). The best way to pinpoint a diamond's true colour is to place it next to another diamond that has previously been graded.


There are also fancy coloured diamonds and these are graded according to their intensity of colour, not lack of it. There are a variety of reasons for diamonds to be coloured. The most common causes, or suggested causes, for the colours yellow, green, blue, brown and pink are described below.


Yellow:

When nitrogen combines with the diamond crystals during the formation stage it causes a surplus electron in the bonding. This surplus electron absorbs blue light, thus giving off a yellow colour. Yellow diamonds also occur when aggregates of three nitrogens combine and cause surplus bond.

Blue:

The elements of boron may also be substituted within a diamond during its formation. Boron absorbs red light, hence in the absence of nitrogen, diamonds containing boron are blue in colour. An example of a diamond containing boron is the famous Blue Hope diamond. Diamonds containing boron also exhibit unusual electrical properties and are semi-conductive in nature. Hydrogen is another impurity that, in high quantities, can cause grey or blue colouring in diamonds. However, these diamonds are not semi-conducting.


Green:
A vacancy in the regular lattice of atoms within a diamond results in a green colouring. Carbon atoms being knocked out of their regular position by other particles cause vacancies. The depth of colour usually extends about 2mm below the diamond's surface. At extremely high temperatures the vacancies can become mobile and can combine with nitrogen to form other colours such as mauve, orange, blue or gold.

Brwon:

It has been suggested that dislocations in the regular lattice of atoms, caused by severe forces deep in the earth, may be responsible for the brown colouring of champagne and cognac diamonds. The dislocated bonds may affect the light wavelength, thus producing a diamond which is coloured, but which contains no impurities.


Pink:

It has also been suggested that combinations of dislocations, vacancies, and non-nitrogen impurities cause the much sought-after colouration in pink diamonds. However these theories are still being developed.

Clarity


During the formation of a diamond it is possible for minute particles of non-crystallised carbon or non-diamond crystals to be caught within the diamond. These imperfections are called inclusions and provide each individual diamond with unique characteristics.


Inclusions may not always be visible to the naked eye, however they do interfere with the passage of light through the diamond. Therefore the fewer inclusions a diamond has, the more valuable it is.

Like colour, clarity is also categorised using international grading scales. The categories of clarity are based upon the number, size and position of the inclusions within the diamond. Gradings range from flawless, and internally flawless, through very small and small inclusions, to imperfect. The clarity gradings are described as follows:


Carat

A carat is the unit of measure used to determine the weight of a diamond. The term "carat" is derived from the original method of using carob tree seeds to weigh diamonds. One seed from this tree was equivalent to one carat.
The actual weight of one carat is now established at 0.2 grams. To assist in accurately describing the weight of diamonds each carat is divided into 100 points. Diamonds of less than one carat in weight are known as "pointers". For example, a 0.15 carat diamond would be called a "15 pointer".
Diamonds are usually weighed prior to setting for more accurate measurements. Diamonds are priced per carat, according to their size and quality. Although the carat weight of a diamond is indicative of its size, it is not necessarily indicative of a diamond's quality. Therefore, where two diamonds have the same carat weight, the one of better quality will command a higher price per carat