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.
Uncle Sam (diamond)
Uncle Sam is the nickname for the largest diamond ever discovered in the United States. It was found in 1924 in Murfreesboro, Arkansas at the Prairie Creek pipe mine, which later became known as the Crater of Diamonds State Park. The diamond was named "Uncle Sam" after the nickname of its finder, Wesley Oley Basham, a worker at the Arkansas Diamond Corporation.