La Grande Stella d’Africa è un diamante tagliato a forma di pera e del peso di 530.20 carati. E’ anche conosciuto come Cullinan I, in quanto è il diamante più grande che si è ricavato dalla lavorazione dell’enorme diamante grezzo Cullinan (3.106,75 carati!). Il Cullinan I attualmente è incastonato sullo Scettro di sant'Edoardo e fa parte dei gioielli della corona britannica assieme agli altri otto Cullinan. E’ possibile vederli presso il Museo della Torre di Londra.
The Stewart Sapphire, which had been owned by the Royal House of Scotland for centuries, was also given to George III. The original owner of the sapphire was reputed to have been King Alexander II of Scotland, who had it set into his crown for his coronation in 1214. Edward I of England took the sapphire along with the Stone of Scone in 1296, during his invasion of Scotland. His grandson, King Edward III, later returned the jewel to his brother-in-law David II of Scotland.
The Imperial State Crown (1937) is worn by the Queen at each State Opening of Parliament. One of the youngest crowns in the collection, it holds a number of much older gems. The crown was remade in 1937 after the previous frame weakened under the weight of the gemstones.