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.
Mmadikola
On 9February 2016, Thembani Moitlhobogi from Mmadikola, won the competition of naming the second-largest gem-quality diamond ever found. He named the stone Lesedi La Rona which means "Our Light". He stated that his reason for the name was that "the diamond is a pride, light and hope of Batswana". During the competition Lucara Diamond Corporation received 11,000 emails and 1,000 SMSs with name suggestions. In addition to naming the diamond, Moitlhobogi also received P25,000 (about $2,170).