The Cullinan I

Weight - 530.2 carats (106.0 g)
Measurement - 53mm x 44mm x 29mm
Currently at - Crown Jewels in the Tower of London
Features - Pear shaped, with 74 facets
Source - South Africa

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 1 1/3 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 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.