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.
Excelsior Diamond
The Excelsior Diamond is a gem-quality diamond, and was the largest known diamond in the world from the time of its discovery in 1893 until 1905, when the larger Cullinan Diamond was found. It was found on June 30, 1893 at the Jagersfontein Mine in South Africa, south east of Kimberley whose fame as a diamond mining center always overshadowed that of Jagersfontein. It had a blue-white tint and weighed 971 old carats or 995.2 metric carats (or 194 g). The Excelsior rates as the third largest rough diamond of gem quality ever found. It was ultimately cut into ten stones weighing from 13 to 68 carats. (2.6 to 13.6 g).