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.
Tereshchenko diamond
The Tereshchenko Diamond, sometimes known as the Tereshchenko Blue, is a 42.92 carat diamond of blue colour that is cut in the pear shape. The diamond is rare, belonging to the Type IIb diamond, and believed to originate from India. The Tereshchenko diamond is the second biggest blue diamond in the world. Shaped by Cartier for a private order by the Tereshchenko family, the diamond is in the rare Type IIb diamond.