OPERA singer Pretty Yende and foreign minister Naledi Pandor were not the only South African presence at the coronation of King Charles III. Also, there were the stones cut from the Cullinan diamond, the largest gem-quality rough diamond ever found. The Cullinan, named after Thomas Cullinan, the chairman of the mining company that found it in South Africa, was mined in 1905 and was bought by the Transvaal colony’s government for presentation to King Edward VII in 1907. It was cut into nine stones and another 97 fragments. Author ROGER SOUTHALL, Professor of Sociology, University of the Witwatersrand The largest…