The Cullinan Diamond, weighing 3,106 carats, is the world’s largest. It was discovered on January 25, 1905, at the Premier Diamond Mine, Transvaal, South Africa. Named for Sir Thomas M. Cullinan (1862–1936), chairman of the Premier Diamond Company, it was cut into nine major stones and 96 smaller brilliants. The total weight of the cut stones was 1,063 carats, only 35 percent of the original weight.

Cullinan I, also known as the “Great Star of Africa” or the “First Star of Africa,” is a pear-shaped diamond weighing 530.2 carats. It is 2.12 inches (5.4 centimeters) long, 1.75 inches (4.4 centimeters) wide, and 1 inch (2.5 centimeters) thick at its deepest point. It was presented to Britain’s King Edward VII (1841–1910) in 1907, and was set in the British monarch’s sceptre with the cross. It is still the largest cut diamond in the world.

Cullinan II, also known as the “Second Star of Africa,” is an oblong stone that weighs 317.4 carats. It is set in the British Imperial State Crown.