<Tr> <Th> Original owner </Th> <Td> Premier Diamond Mining Company Ltd </Td> </Tr> <Tr> <Th> Owner </Th> <Td> Queen Elizabeth II in right of the Crown (I and II) and as a private individual (III--IX) </Td> </Tr> <P> The Cullinan Diamond is the largest gem - quality rough diamond ever found, weighing 3,106.75 carats (621.35 g), discovered at the Premier No. 2 mine in Cullinan, modern - day South Africa, on 26 January 1905 . It was named after the chairman of the mine, Thomas Cullinan . </P> <P> It was presented to King Edward VII of the United Kingdom for his 66th birthday and cut into several polished gems, the largest of which is named Cullinan I or the Great Star of Africa, and at 530.4 carats (106.08 g) it is the largest clear cut diamond in the world . It was the largest polished diamond of any colour until the discovery in 1985 of the Golden Jubilee Diamond (545.67 carats (109.13 g)), also from the Premier Mine . Cullinan I is mounted in the head of the Sovereign's Sceptre with Cross . The second - largest is Cullinan II or the Second Star of Africa; at 317.4 carats (63.48 g) it is the fourth - largest cut diamond in the world, and is mounted in the Imperial State Crown . Both diamonds are part of the Crown Jewels which belong to the monarch in right of the Crown . </P>

Where was the world's largest diamond found