An extremely rare, acorn-sized, blue diamond has been recovered in the Cullinan mine of South Africa, announced this week by Petra Diamonds.
According to the company’s press release, the 29.6 carat diamond is “a vivid blue with extraordinary saturation, tone and clarity”. Still in its rough form, experts believe that the stone could sell in the $15-$20 million range. The company will announce what it plans to do with the diamond within the next week or so.
Since opening in 1903, the Cullinan mine has been the main source of blue diamonds in the world. However, the output of the rare blue stones represent less than 0.1% of the diamonds found in the mine. The blue shading in a diamond is due to the presence of the chemical element boron when the stone was formed.
The location first became famous in 1905 with the discovery of the Cullinan Diamond. At 3,106 carats, it still is the largest rough diamond ever found. Once it was cut, the stone was formed into two diamonds that are now part of Britain’s Crown Jewels located in the Tower of London.
The larger of the two diamonds is the 530-carat First Star of Africa. It is still the largest flawless cut diamond in the world and is mounted at the top of the Sovereign’s Sceptre. The second diamond, called the Second Star of Africa, is a 317-carat polished stone which forms the centrepiece of the Imperial State Crown.
World renowned diamond company De Beers originally owned Cullinan mine, they sold it to Petra Diamonds in 2008. Petra made the news in April 2013 when they recovered a blue diamond that weighed in at 25.5 carats. It was sold for $16.9 million less than a month later.