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.

The Government of Transvaal presented the diamond, along with Cullinan II (the Lesser Star of Africa) to King Edward VII on November 9, 1907 at Sandringham House. The King then announced to the Secretary of State for the Colonies, Lord Elgin, that he accepted the magnificent gift ‘for myself and successors’, thus effectively designating the stones as Crown Jewellery.

Queen Alexandra (left) and Queen Mary (right) wearing Cullinans I and II in a brooch setting

The first setting of the stones was a temporary one; together with Cullinan II, it was mounted as a brooch for Queen Alexandra. The Queen didn't wear it very often and only one photograph of Alexandra wearing the brooch exists. 

After Edward VII’s death in 1910, the new King commissioned Garrard to incorporate the diamond into the existing Crown Regalia, thus fulfilling King Edward’s wish to include the stone in the Crown Jewels. To that end, the Sovereign’s Sceptre with Cross was modified to hold Cullinan I. The structure which holds the diamond is hinged so that the stone may be removed and worn separately. 

Queen Mary has worn Cullinan I and Cullinan II separately several times. She also wore them in a brooch setting, with Cullinan III and IV (also in a brooch setting) handing from her diamond necklaces. The stone has very rarely been removed from its sceptre setting since 1930s.

The Sovereign's Sceptre with Cross

The Sceptre with Cross was originally made for Charles II but has undergone a number of alterations, particularly in 1820 for the coronation of George IV; back then, an enamelled rose, thistle and shamrock were all added to the monde. The most significant alteration was undoubtedly the 1910 one though, when the sceptre was altered to receive the great Cullinan diamond. The sceptre also had to be reinforced as the weight of the diamond is so large.

To read more about the fascinating story of the uncut diamond, have a look at this article: Day in History - The world’s largest diamond ever, the Cullinan, is found.

Sources and photo credits: Royal Collection, “Diamond: A Journey to the Heart of an Obsession” by Matthew Hart, “The Queen’s Diamonds” by Hugh Roberts, "The Queen's Jewels" by Leslie Field