Cullinan Diamond
The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing , discovered at the Premier No. 2 mine in Cullinan, South Africa, on 26 January 1905. It was named after Thomas Cullinan, the mine's chairman.
Oppenheimer Blue
The diamond was named for its previous owner Philip Oppenheimer. It is cut into a rectangle (emerald cut). The Oppenheimer Blue is the largest fancy vivid blue diamond classified by the Gemological Institute of America ever sold at auction; it sold at Christie's in Geneva in May 2016 for US$50.6 million (GBP 34.7m; 56.83m SFr). Two telephone bidders had competed for the diamond; the identity of the purchaser is not publicly known.