On January 26, 1905 the Cullinan diamond was discovered by Frederick Wells, the surface manager of the Premier Diamond Mining Company in Cullinan, South Africa. The Transvaal government bought the stone for £150,000 and presented it to King Edward VII on his 66th birthday in 1907.
As a rough diamond crystal, the Cullinan weighed more than 3,000 carats. It was eventually cut into nine large gem-quality stones and several smaller fragments by Abraham and Joseph Asscher, who owned the Royal Asscher Diamond Copany in Amsterdam. The Asscher brothers studied the stone for three months before deciding where it should be cut.
The largest stone, the Cullinan I (also known as the Great Star of Africa) was cut into a 530-carat pear shape and set into the Royal Sceptre. The Cullinan II, a cushion-cut that weighs 317 carats, was mounted in the center front of the Imperial State Crown of Great Britain. Cullinan III was cut into a pear shape weighing 94.4 carats and mounted in the finial of Queen Mary’s crown (it can also be worn as a pendant-brooch). Cullinan IV was set in the band of Queen Mary’s crown after being cut into a 63.6 carat cushion. The heart-shaped Cullinan V started out as a brooch but is now used as a replacement for the Koh-i-Noor diamond, which was used in the crown made for Queen Elizabeth (the Queen Mother) in 1937. Cullinan VII, weighing in at 8.8 carats, is a pendant drop on a diamond brooch that also includes the 6.8 carat cushion-cut Cullinan VIII. Finally, Cullinan IX was cut into a 4.4-carat pear shape and set on a ring.
As Crown Jewels, many of these pieces make appearances at coronations and other state occasions. If you want to see them up close, they’re on permanent display in the Tower of London.