Cullinan Diamond
The Cullinan diamond was found below the surface at Premier Mine in Cullinan, Transvaal Colony, by Frederick Wells, surface manager at the mine, on 26 January 1905. It was approximately long, wide, deep, and weighed . Newspapers called it the "Cullinan Diamond", a reference to Sir Thomas Cullinan, who opened the mine in 1902. It was three times the size of the Excelsior Diamond, found in 1893 at Jagersfontein Mine, weighing . Four of its eight surfaces were smooth, indicating that it once had been part of a much larger stone broken up by natural forces. It had a blue-white hue and contained a small pocket of air, which at certain angles produced a rainbow, or Newton's rings.
Lesotho Promise
The Lesotho Promise, a 603 carat (121 g) diamond stone of exceptional colour was unearthed on 22 August 2006 at the Letseng diamond mine in the mountain kingdom of Lesotho. Announced on 4 October 2006, it was the largest reported find this century and the 15th largest diamond ever found. The stone is rated 'D', the top colour band for diamonds.