Diamonds fit for a queen's jubilee

18.05.12

Weighing 3106 carats in its rough state and measuring 10cm x 6.2cm x 5.2cm, the Cullinan - named after the mining company's chairman Thomas Cullinan - was also exceptional for its blue-white colour and purity.

The prime minister of the Transvaal, a British colony, suggested his government should acquire the Cullinan and present it to Edward VII on his 66th birthday.

Cutting the stone was entrusted to the celebrated firm of IJ Asscher of Amsterdam. It was too large to be cut into a single gem, so cleaving or sawing was necessary. 

The first blow broke the knife but left the diamond intact. A second attempt split it in two. Eight months of grinding and polishing followed, with the result of nine principal numbered stones, 96 small brilliants and nine carats of unpolished fragments.

The total weight of the gems cut from the Cullinan was 1055.9 carats.

In 1909, the two largest gems, the biggest colourless and flawless cut diamonds in the world, were formally presented to King Edward VII at Windsor Castle and were eventually set at the head of the Sovereign's Sceptre and in the Imperial State Crown.

Source: Adelaide Now