Will this be the most expensive diamond ever?

On the 11th November this year, Sotheby’s will be hoping to set a record for the auction of what is potentially the world’s most valuable diamond. Found in South Africa’s Cullinan Diamond mine in January 2014, a remarkable 29.6ct rough blue diamond has been carefully cut, polished and facted into a 12.03ct, internally flawless, vivid blue diamond, known as the “Blue Moon”.

Purchased by Cora International in February 2014 for $25.5million, a 6 month cutting a polishing process has yielded a perfect blue diamond that may sell for anywhere from $35 – $55million, if pre-sale estimates are to be believed.

“Weighing in at 12.03 carats, the Blue Moon diamond is a simply sensational stone of perfect color and purity,” said David Bennett, worldwide chairman of Sotheby’s international jewelry division, in a statement. “Blue, for me, is the most mysterious and magical of all the colors of diamond, and the Blue Moon will now take its place among the most famous gems in the world.”

The Cullinan Diamond Mine, previously owned by De Beers, but now owned by Petra Diamonds, is one of the few diamond mines world-wide known to produce natural blue diamonds. Naturally occurring blue diamonds are exceptionally rare and are formed when Boron-impurities are incorporated into the diamond during it’s growth process. To find a blue diamond combining such an intense depth of colour and such a  significant size, makes the Blue Moon diamond a truly significant diamond.

The Blue Moon will be on display in Hong Kong, London and New York ahead of it’s scheduled Geneva auction on the 11th November. Should the pre-sale estimates of the Blue Moon be reached during the Sotheby’s auction, the diamond could shatter the records for both the most expensive diamond ever (currently a record of $46million) and the highest per carat price of any diamond (currently $3.3million per carat).

Videos of the Blue Moon can be viewed on both the Cora International and Sotheby’s websites.

[Photographs courtesy of Petra Diamonds (left) and Cora International (right), Blue Moon photographed by Tino Hammid]