Tag Archives: Petra Diamonds

A Possible Record-Breaking Diamond


A 12.03-carat Internally Flawless Fancy Vivid Blue diamond could become a record-breaking stone come this November as it goes to auction by Sotheby’s.

The “Blue Moon Diamond”, named for its once-in-a-blue-moon kind of rarity is expected to sell for between $35 and $55 million at their Magnificent Jewels and Noble Jewels auction in Geneva.

The original stone was recovered by Petra Diamonds at the Cullinan mine in South Africa in January 2014.

blue rough

In it’s original state, it weighed in at 29.62-carats and was quickly sold for $25.6 million to Cora International.   The New York-based firm then spent the next 6 months cutting and polishing the fabulous blue stone to its current form.

If the Blue Moon Diamond does end up selling for more than $32.6 million, it will break the record currently held by the 9.75-carat Zoe Diamond as the most expensive blue diamond ever sold.  If it sells for more than $46.2 million, it will set the record for the most expensive diamond of any kind sold at auction.


A Happy Valentine’s Day For Cora International

blue diamond - Cullinan

Cora International, a New York-based diamond company, celebrated Valentine’s Day with the purchase of a diamond.    At $25.6 million, the diamond wasn’t your average Valentine’s Day trinket.   Considering the diamond was blue and weighed in at 29.6 carats in the rough….there was nothing average about the purchase.

Cora, through the South African company Golden Yellow Diamonds, purchased the diamond at Petra Diamonds’ tender last week.

Petra Diamonds originally recovered the rare blue stone in January from their Cullinan Mine in Pretoria, South Africa.  At the time of the find, Petra’s Chief Executive Johan Dippenaar referred to the blue diamond as “the most significant stone we’ve ever, in terms of blue stones, recovered.”

Petra last recovered a sizeable blue diamond from the Cullinan mine in April 2013.   The 25.5 carat stone sold at auction a month later for $16.9 million.   Based on that sale, industry analysts said that the most recent stone should sell for between $15 and $20 million.    The fact that the newer stone sold for over $200,000 more per carat in less than a year says a lot about the increasing rarity and value for colour diamonds.

Cora International also made headlines in the colour diamond world in November 2011 when they bought the Sun-Drop Diamond at auction for 10.9 million.   The pear-shaped yellow stone weighed in at 110.3 carats and the final auction price still stands as a record for that colour of diamond.

A Rare Blue Diamond Find

blue diamond - Cullinan

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.