Cullinan Diamond : The largest gem diamond ever found

This 3,106.75 carat diamond is the largest gem diamond ever found. It was discovered on January 26, 1905 at the Premier Diamond Mining Company in Cullinan, Gauteng, South Africa, by Frederick Wells, a mine superintendent. Although a carbonado found in Brazil weighed more than 3,600 carats (720 g), no gem-quality material could be extracted from it. The stone was named after Sir Thomas Cullinan, the owner of the diamond mine.

The stone was bought by the Transvaal government for $800,000 and presented to King Edward VII. It was cut into three large parts by Asscher Brothers of Amsterdam, and eventually into some 11 large gem-quality stones, 96 smaller brilliants, and 9.5 carats of unpolished pieces. At the time, technology had not yet evolved to guarantee quality of the modern standard, and cutting the diamond was considered difficult and risky. In order to enable Asscher to cut the diamond in one blow an incision was made, half an inch deep. Then a specifically designed knife was placed in the incision and the diamond was split in one heavy blow. The diamond split through a defective spot which was shared in both halves of the diamond.

The Cullinan I was the largest gem produced from the rough stone. It is a pear shaped stone of 530.2 carats and is the world's largest cut diamond. The Cullinan I is now in the head of the royal scepter in the British crown jewels. The second largest cut diamond, the Cullinan II, is a cushion-shaped stone weighing 317.4 carats, and is set in the British imperial state crown.

Excelsior Diamond : named after the Jubilee in honor of Queen Victoria

On the evening of June 30, 1893, an African mine worker picked up an immense diamond in a shovelful of gravel which he was loading into a truck; he hid it from his overseer and delivered it directly into the hands of the mine manager. The diamond was discovered in the Jagersfontein mine in the Orange River Colony. The lucky Kaffir was rewarded he received $2500 and a horse equipped with saddle and bridle. The diamond had a blue-white tint and weighed 971 3/4 carats (194.2 g) or equivalent to 995.2 metric carats

The shape the diamond stone was flat on one side and rose to a peak on the other, rather like a loaf of rye bread. Apparently it was this fact which caused the diamond to be given the name of Excelsior, meaning higher. The stone was ultimately named the Jubilee in honour of the celebration of the sixtieth anniversary of the accession of the late Queen Victoria.

Until 1905, when the larger Cullinan diamond was found, the Excelsior was the largest known diamond in the world. The rough stone weighed 971 3/4 carats, measured two and one-half inches in length, two inches in breadth, and one inch in thickness.

Like the Cullinan Diamond, its predecessor had a fault that prevented its becoming a single gem; this was a black spot in the centre which made it necessary to cleave it, as the Cullinan was cleaved. After prolonged study it was decided to first cleave the diamond into ten pieces: this operation which was performed by Mr. A. Asscher, resulting in the three largest pieces weighing 158, 147 and 130 carats. The larger portion was cut into an absolutely perfect brilliant, weighing 239 international carats of 205 milligrams and measuring one and five-eighths inches in length, one and three-eighths in breadth, and one inch in depth.

The polishing was supervised by Henry Koe and yielded 21 gems, ranging from 70 carats to less than 1 carat. They totalled 373.75 carats which represented a loss in weight of almost 63 percent. The final result, however, was considered to have been better than anyone had expected. The specifications of the larger gems cut from the Excelsior are as follows:

(metric carats)
Excelsior I ... 69.68 carats ... pear shape
Excelsior II ... 47.03 carats ... pear shape
Excelsior III ... 46.90 carats ... pear shape
Excelsior IV ... 40.23 carats ... marquise
Excelsior V ... 34.91 carats ... pear shape
Excelsior VI ... 28.61 carats ... marquise
Excelsior VII ... 26.30 carats ... marquise
Excelsior VIII ... 24.31 carats ... pear shape
Excelsior IX ... 16.78 carats ... pear shape
Excelsior X ... 13.86 carats ... pear shape
Excelsior XI ... 9.82 carats ... pear shape

The Excelsior gems were sold seperately, three of them were bought by Tiffany & Co., in their old store in Union Square in New York City. The names of the other buyers have not been disclosed but it is known that De Beers displayed one of the marquise-shaped fragments at the 1939 World's Fair in New York.

Is It Or Isn’t It? The World’s Largest Diamond

Unconfirmed reports are in from South Africa regarding the discovery of what may be the world’s largest diamond.

According to Brett Jolly, a shareholder in the small South African mining company that found the diamond, the stone is around 7,000 carats, twice the size of the world’s largest diamond - the Cullinan Diamond.

In 2000 police foiled a plan to steal the 203-ct. flawless pear-shaped Millennium Star diamond and 11 other rare blue diamonds, including the 27.64-ct. blue Heart of Eternity diamond from London’s Millennium Diamond. In a scene right out of the James Bond movie "The World is Not Enough," the robbers planned to make their getaway via a speedboat on the nearby Thames River. But police, acting on a tip given several weeks ago, had prepared for the theft and had officers stationed around the Millennium Dome dressed as members of the cleaning staff carrying weapons in their refuse bags. Some 100 officers lay in wait as a gang attempted to use a mechanical digger to steal the gems valued at £350 million. The robbers only managed to damage the glass display case, however, the police, had swapped the jewels for worthless copies

The Cullinan, the centerpiece of the British crown jewels, was discovered near Pretoria in 1905 and weighs about 3,000 carats. The unpolished Cullinan, also known as the Star of Africa, was 3,107 carats when De Beers found it in 1905. The cut stone now resides in the Tower of London, set in the sceptre of King Edward VII.

But industry experts are skeptical about the unconfirmed claim. In a photograph emailed to the BBC, the 'stone' appears to be about the size of a coconut, and has a greenish tinge.

But a spokesman for De Beers, the world's biggest diamond mining company, said the north-west province was not known for producing gems and greenish stones were even rarer.

Ernie Blom, chairman of the South African Diamond Council and president of the World Federation of Diamond Bourses, said from what he could see in the photograph the gem did have the characteristics of a diamond in terms of shape and color.

'It would be an extremely rare find. It would almost be like finding another Rembrandt,' he said. He said the stone would have to be certified by an expert.

Source : Jewelry.com.

Cullinan Diamond

The Cullinan Diamond, found by Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, Gauteng, South Africa, on January 26, 1905, is the largest rough gem-quality diamond ever found, at 3,106.75 carats (621.35 g). Although a carbonado found in Brazil weighed more than 3,600 carats (720 g), no gem-quality material could be extracted from it. The stone was named after Sir Thomas Cullinan, the owner of the diamond mine.

Sir William Crookes performed an analysis of the Cullinan diamond and mentioned among others its remarkable clarity but also a black spot in the middle. The colours around the black spot were very vivid and changed as the analyzer was turned. According to Crookes this pointed to severe internal strain. Such strains are not uncommon for diamonds, and have actually resulted in causing diamonds to explode when reaching the surface, or even in the pockets of the miners due to the exposure to the miner's body warmth.

The stone was bought by the Transvaal government and presented to King Edward VII. It was cut into three large parts by Asscher Brothers of Amsterdam, and eventually into some 11 large gem-quality stones and a number of smaller fragments. At the time, technology had not yet evolved to guarantee quality of the modern standard, and cutting the diamond was considered difficult and risky. In order to enable Asscher to cut the diamond in one blow an incision was made, half an inch deep. Then a specifically designed knife was placed in the incision and the diamond was split in one heavy blow. The diamond split through a defective spot which was shared in both halves of the diamond.

"The tale is told of Joseph Asscher, the greatest cleaver of the day," wrote Michael Hart in his book Diamond: A Journey to the Heart of an Obsession, "that when he prepared to cleave the largest diamond ever known, the 3,160 carat (632 g) Cullinan, he had a doctor and nurse standing by and when he finally struck the diamond and it broke perfectly in two, he fainted dead away."

The largest polished gem from the stone is named Cullinan I or the Great Star of Africa (Picture), and at 530.2 carats (106.04 g) was the largest polished diamond in the world until the 1985 discovery of the Golden Jubilee diamond, 545.67 carats (109.13 g), also from the Premier Mine. Cullinan I is now mounted in the head of the Sceptre with the Cross. The second largest gem from the Cullinan stone, Cullinan II or the Lesser Star of Africa, at 317.4 carats (63.48 g), is the third largest polished diamond in the world and is also part of the British crown jewels, as it forms a part of the Imperial State Crown. Both gems are on display at the Tower of London, as parts of the Crown Jewels of the United Kingdom.

In 1905, transport from South Africa to England posed a bit of a problem with regard to security. Detectives from London were placed upon a steamer ship that was rumoured to carry the stone, but this was a diversionary tactic. The stone on that ship was a fake, meant to attract those who would be interested in stealing it. The actual diamond was sent to England in a plain box via parcel post.

Rumours abound of a second half of the Cullinan diamond, as there are certain indications that the diamond was part of a larger crystal. It is suggested that before Frederick Wells sold the diamond to Sir Thomas Cullinan he broke off a piece which sized in at about 1,500 to 2,000 carats (300 to 400 g). If this were true, the original Cullinan diamond would have weighed approximately 5,000 carats (1 kg).