||This article needs additional citations for verification. (June 2010)|
The rough diamond; below it (not to same scale) the nine largest pieces after the split
|Weight||3106.75 carats (603.35 g)|
|Color||white (exact colour grade unknown; Gems & Gemology's examination results stated probably D or at least E)|
|Cut||Assorted (cushions, pears, marquises)|
|Country of origin||South Africa|
|Mine of origin||Premier Mine|
|Cut by||Asscher Brothers|
|Original owner||Premier Diamond Mining Co.|
|Current owner||British Crown|
|Estimated value||over £200 million, US$400 million|
The Cullinan diamond is the largest gem-quality diamond ever found, at 3106.75 carat (621.35 g, 1.37 lb) rough weight. About 10.5 cm (4.1 inches) long in its largest dimension, it was found 26 January 1905, in the Premier No. 2 mine, near Pretoria, South Africa.
The largest polished gem from the stone is named Cullinan I or the Great Star of Africa, and at 530.4 carats (106.1 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 (63.5 g), is the fourth largest polished diamond in the world. Both gems are in the Crown Jewels of the United Kingdom.
The Cullinan diamond was found by Thomas Evan Powell, a miner who brought it to the surface and gave it to Frederick Wells, surface manager of the Premier Diamond Mining Company in Cullinan, South Africa on 26 January 1905. The stone was named after Sir Thomas Cullinan, the owner of the diamond mine.
Sir William Crookes performed an analysis of the Cullinan diamond before it was cut and mentioned its remarkable clarity, but also a black spot in the middle. The colours around the black spot were very vivid and changed as the analyser was turned. According to Crookes, this pointed to internal strain. Such strain is not uncommon in diamonds.
The stone was bought by the Transvaal government and presented to King Edward VII on his birthday. It was cut into three large parts by Asscher Brothers of Amsterdam, and eventually into 9 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. 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.
In 1905, transport from South Africa to England posed a security problem. Detectives from London were placed on a steamboat 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, albeit registered.
The story goes that when the diamond was split, the knife broke during the first attempt. "The tale is told of Joseph Asscher, the greatest cleaver of the day," wrote Matthew 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 3,106 carats (621 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." Lord Ian Balfour, in his book "Famous Diamonds" (2000), dispels the fainting story, stating it was more likely Joseph Asscher would have celebrated, opening a bottle of champagne.
Rumours abound of a "second half" of the Cullinan diamond. According to Sir William Crookes the original, uncut diamond was itself "a fragment, probably less than half, of a distorted octahedral crystal; the other portions still await discovery by some fortunate miner." Crookes thus indirectly indicates that the original, larger crystal broke in a natural way and not by a man-made cut. Others[who?] have speculated that before Frederick Wells sold the diamond to Sir Thomas Cullinan he broke off a piece which sized in at about 1,500 carats (300 g) to 2,000 carats (400 g).
Principal diamonds cut from the Cullinan 
The Cullinan was split and cut into 7 major stones and 96 smaller stones. Edward VII had the Cullinan I and Cullinan II set respectively into the Sceptre with the Cross and the Imperial State Crown, while the remainder of the seven larger stones and the 96 smaller brilliants remained in the possession of the Dutch diamond cutting firm of Messers I. J. Asscher of Amsterdam who had split and cut the Cullinan, until the South African Government bought these stones and the High Commissioner of the Union of South Africa presented them to Queen Mary on 28 June 1910.
|Name||Number of Carats||Shape||Use|
|Cullinan I||530.2 carats||pear||Set in the head of the Sceptre with the Cross. It may also be hung as the pendant from the Cullinan II in a brooch.|
|Cullinan II||317.4 carats||rectangular cushion||Set in the front of the circlet of the Imperial State Crown. It may also be used together with the Cullinan I as a brooch.|
|Cullinan III||94.4 carats||pear||Originally set in the on the orb at the top of the Crown of Queen Mary. It now hangs from the Cullinan IV in a brooch.|
|Cullinan IV||63.6 carats||square cushion||Originally set in the front of the circlet of the Crown of Queen Mary. It now forms part of a brooch together with the Cullinan III.|
|Cullinan V||18.8 carats||heart||Set in the center of a brooch forming a part of the stomacher of the diamond and emerald Delhi Durbar Parure.|
|Cullinan VI||11.5 carats||marquise||Originally given by Edward VII to Queen Alexandra. After his death she gave this stone to Queen Mary who had it set as a pendant hanging from the diamond and emerald necklace in the Delhi Durbar Parure.|
|Cullinan VII||8.8 carats||marquise||It hangs from the brooch containing the Cullinan VIII and forming as part of the stomacher of the Delhi Durbar Parure.|
|Cullinan VIII||6.8 carats||cushion||Set in the center of a brooch forming part of the stomacher of the Delhi Durbar Parure.|
|Cullinan IX||4.4 carats||pear||Set as the bezel in a ring.|
See also 
- A carbonado found in Brazil weighed more than 3,600 carats (720 g), but no gem-quality material could be extracted from it.
- Overview of the different Cullinan diamonds
- Crookes: Diamonds (1909) Page 78
- Goodchild: Precious Stones (1908) Page 140
- Crookes: Diamonds (1909) Page 77 (A photo of the rough Cullinan, marked as number 17, is facing page 80.)
- Crookes: Diamonds (1909) Page 79
- Dickinson, Joan Y. (1965). The Book of Diamonds. New York City: Crown Publishers, Inc. p. 110. ISBN 978-0-486-41816-2.
- With the exception of the Cullinan VI which Edward VII bought and gave to Queen Alexandra in1907 and who on his death gave it to Queen Mary
- ’’The Queen's Jewels. The Personal Collection of Elizabeth II.’’ Leslie Field. Harry N. Abrams, Incorporated, @ 1987. Times Mirror Books. INBN 0-8109-1525-1. p. 72.
- Also known as the Great Star of Africa.
- First of the Lesser Stars of Africa
- First of the Lesser Stars of Africa.
- Second of the Lesser Stars of Africa.
- Based on the information in ‘’The Queen's Jewels. The Personal Collection of Elizabeth II’’, pp. 72–77.
- The Cullinan – a detailed account with pictures
- The Monarchy Today: The Crown Jewels
- Daily Mail article with many photographs
- "Jewellery from world's largest diamond to go on display". BBC News Online. 15 May 2012. Retrieved 2012-05-18. "So incredible was its discovery that the moment it was found at the Premier Mine it was thrown out of the window of the mine manager's office because it was thought to be a worthless crystal."