Which is the largest diamond ever found?

The largest gem-quality rough diamond ever found is the Cullinan Diamond, which weighed about 3,106 carats, or roughly 621 grams. It was discovered on 26 January 1905 at the Premier Mine near Pretoria, South Africa, and named after the mine’s owner, Thomas Cullinan. The stone was presented to King Edward VII and later cut into nine major stones and around 100 smaller ones. The biggest, the 530-carat Great Star of Africa, is set in the Sovereign’s Sceptre, while the 317-carat Cullinan II sits in the Imperial State Crown. In 2024 a 2,492-carat diamond found at the Karowe mine in Botswana became the second-largest ever discovered.