British Royal Jewels: Cullinan I Diamond (The Star of Africa)

Cullinan I or the Star of Africa is the largest of the Cullinan Diamonds cut from the original Cullinan stone, which had been discovered in South Africa in 1905.

The Cullinan I Diamond on its own (left) and mounted in the Sceptre (right)

The Star of Africa is colourless, pear-shaped, and weights 530.2 carats (106.1 g). For many years, it had been the largest polished diamond in the world until the 1985 discovery of the Golden Jubilee Diamond, which weights 545.67 carats (109.13 g). Cullinan I still remains the largest colourless diamond in the world though: the Golden Jubilee one has a yellow-brown colour. Incidentally, both diamonds were discovered at the same mine – the Premier Mine in South Africa.