At 530.20 carats the Cullinan I, or Great Star Africa diamond, is the largest cut diamond in the world. Pear-shaped, with 74 facets, it is set in the Royal Scepter (kept with the other Crown Jewels in the Tower of London).

The Cullinan I diamond was cut from the 3,106-carat Cullian diamond, the largest diamond ever found. The original Cullinan diamond was discovered in Transvaal, South Africa in l095.

The second-largest diamond cut from the Cullinan is the Cullinan II diamond, also known as the Lesser Star of Africa diamond.