The Cullinan Diamond

The Cullinan Diamond

$400 million

The Cullinan Diamond is the largest gem-quality rough diamond ever found, weighing 3,106.75 carats, discovered in 1905 in South Africa and cut into multiple gems now owned by the British Crown Jewels.

Estimated value as of 2026 · Source: Multiple sources including 1stdibs, masinadiamonds, and nazarsandco