A rare blue seven carat diamond from Petra Diamonds’ Cullinan mine recently sold for US$9.49 million, or US$1.35 million per carat. This represents a new record price per carat for any gemstone sold at auction and the highest price for a fancy vivid blue diamond sold at auction.
The fancy vivid blue, internally flawless, cushion-shaped diamond weighing 7.03 carats sold as the centre piece of Sotheby’s Magnificent Jewels auction in Geneva. Its sale price surpassed the world record price per carat achieved for any gemstone at auction, which was formerly held by a 3.73 carat, fancy vivid blue pear-shaped diamond which sold for US$1.33 million per carat at a Sotheby’s auction in May 2008. It also surpassed the world record for a fancy vivid blue diamond sold at auction, which was formerly held by a 6.04 carat, fancy vivid blue diamond ring which sold for US$8.0 million at a Sotheby’s auction in October 2007.
Blue diamonds are among the rarest of all gems and this stone, which has the highest possible grading, was cut from a 26.58 carat rough discovered in 2008 at Petra Diamonds’ Cullinan diamond mine. This mine in South Africa is the world’s most consistently reliable source of blue diamonds.
The Cullinan mine was the source of two of the largest stones in the British Crown Jewels, the Great Star of Africa and the Lesser Star of Africa, both of which were cut from the largest gem diamond ever recovered, the Cullinan diamond, at 3,106 carats rough.
In 1969 Sotheby’s sold another famous diamond from Cullinan, the 69.42 carat polished diamond that Richard Burton gave to Elizabeth Taylor and came to be known as the Taylor Burton diamond.