Sotheby's Expects $3M/ct. for Cartier Blue Diamond

[Rapaport News]  A blue diamond ring will go under the hammer in Geneva next month with an estimated price tag of $15 million to $25 million, or up to $3.1 million per carat.

The square emerald-cut, 8.01-carat, fancy vivid blue diamond, named the ‘Sky Blue Diamond,’ will headline Sotheby’s Magnificent Jewels and Noble Jewels auction on November 16. 

Fancy vivid blue, the highest color grade possible for a blue diamond, is awarded to no more than 1 percent of blue diamonds submitted to the Gemological Institute of America, Sotheby’s said. Mounted by Cartier, the diamond also has “excellent” polish and is a type-IIb stone. 

The Sky Blue Diamond is the latest in a string of blue diamonds sold by leading auctioneers. The 14.62-carat Oppenheimer Blue fetched a world-record $57.5 million at a Christie’s sale in Geneva in May, while Sotheby’s brought in $48.5 million for the Blue Moon of Josephine in the Swiss city last November.