The blue diamond, described as “a truly significant find” due to both its rarity and size, was recovered by diamond mining group Petra Diamonds from its Cullinan mine, located northeast of Pretoria.
The stone required further analysis before its potential value could be assessed, but analysts have reportedly estimated that it could be a record-breaker.
“So far, the highest price on record paid for a rough diamond was US$35.3 million [AU$37.7 m], paid in February 2010 for a 507-carat white stone, also recovered from Cullinan,” financial analyst Martin Potts told Reuters. “We think that this stone may break that record.”
According to a company media release, Petra would not be selling the new find before the end of the financial year as it still needed to evaluate the diamond’s “optimal route to market”.
A fruitful history
The Cullinan mine is no stranger to large diamonds, having been the source for the discovery of the largest piece of diamond rough ever found. The 3,106-carat Cullinan diamond was discovered in 1905, with major cuts currently adorning the Crown Jewels of the United Kingdom in the form of the 530-carat First Star of Africa and the 317-carat Second Star of Africa.
According to the media statement, the Cullinan is also renowned as “the world’s most important source of blue diamonds”. The mine has yielded a number of large blue diamonds since it was acquired by Petra in 2008, including: a 39.9-carat diamond which sold for US$8.8 million (AU$9.4 m) in 2008; a 25.5-carat diamond which sold for US$16.9 million (AU$18 m) in 2013; and a 29.6-carat diamond which sold in February this year for US$25.6 million (AU$27.2 m).
It was also the source of the Star of Josephine blue diamond, a fancy vivid blue and internally flawless 7-carat polished stone that was produced from a 26.6-carat piece of blue diamond rough.
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