<P> Cullinan produced stones of various cuts and sizes , 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 . 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 , weighing 317.4 carats ( 63.48 g ) , mounted in the Imperial State Crown . Both diamonds are part of the Crown Jewels of the United Kingdom . </P>
where is the star of africa diamond kept
part of the Crown Jewels of the United Kingdom