At his coronation Saturday, King Charles III will hold a royal scepter featuring the Star of Africa—the biggest diamond in the world—but some critics say the British royal family should hand the jewel over to South Africa, where it was found. The 530 carat stone was discovered in 1905 and given to the British monarchy by the colonial government in South Africa which was controlled by the British at the time. “The diamond needs to come to South Africa. It needs to be a sign of our pride, our heritage and our culture,” said Mothusi Kamanga, a lawyer and activist who has helped to promote a petition calling for the diamond’s return. “I think generally the African people are starting to realize that to decolonize is not just to let people have certain freedoms, but it’s also to take back what has been expropriated from us.” Officially known as Cullinan I, the jewel was cut from a massive 3,100 carat stone mined close to Pretoria, while another smaller cut, Cullinan II, was set into the Imperial State Crown used by the British monarch at ceremonial events. The crown and scepter are kept along with other crown jewels in the Tower of London.