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.
DeYoung Red Diamond
The DeYoung Red Diamond is a 5.03-carat unmounted rare red diamond. It is the third-largest red diamond in the world, and the only one on public display. Sydney DeYoung (for whom the diamond is named) obtained the diamond, which was mistaken for a garnet, at a flea market. The diamond was given to the Smithsonian Institution after DeYoung's death in 1986.