The Cullinan mine is renowned for its large diamonds, with many stones discovered there now set within the Crown Jewels. These include the Great Star of Africa which was discovered at the mine in 1905.
“Blue diamonds are the rarest of all diamond and Cullinan is one of the largest producers of the stones,” Jeremy Dibb, an analyst at broker Canaccord said. “Cullinan produced an important blue stone following the acquisition by Petra Diamonds.”
This previously discovered 26.6 carat fancy vivid blue stone was cut into an internally flawless 7.03 carat polished stone.
This blue diamond was sold at auction at Southeby’s in May 2009 and achieving a record price per carat for any gemstone sold at auction, hitting $9.49m or $1.35m per carat.
Petra Diamonds, a member of the FTSE 250 index, saw its shares rise 0.6p to 108p following the discovery.
The most famous blue diamond is the Hope Diamond housed in the Hall of Geology, Gems and Minerals at the National Museum of Natural History.