Largest gem diamond ever discovered.
It weighed about 3,106 carats in rough form when it was found in 1905 at the Premier mine in Transvaal, S.Af. Named for Sir Thomas Cullinan, who had discovered the mine, the colourless stone was purchased by the Transvaal government and presented to Britain's King Edward VII. It was cut into 9 large stones and about 100 smaller ones, all flawless; they are now part of the British crown jewels .