Deep Blue Diamond Fetches $1 Million a Carat at Auction

On Nov. 14 at Sotheby’s Geneva, a 10.48 ct. fancy deep blue briolette diamond fetched $1.036 million a carat—a world record per-carat price for a deep blue stone.

The buyer was noted diamond collector Laurence Graff, who paid $10.8 million (a world record for a briolette diamond). The piece sparked a bidding war, and the final price more than doubled the piece’s presale estimate of $3.5 million–$4.5 million.


10.48 ct. fancy deep blue briolette diamond (Photos courtesy of Sotheby’s)

Another milestone was set by a Cartier conch pearl bracelet designed for Queen Victoria Eugenia of Spain. The $3.4 million sale price established a world record for a conch pearl piece, and more than quadrupled its $800,000–$1.4 million estimate.


Cartier conch pearl bracelet

In a statement, David Bennett, chairman of Sotheby’s Jewelry Department in Europe and the Middle East, called the bracelet “not only one of the greatest of Cartier’s creations, but also, I believe, one of the most important jewels of the last century.”

Overall, the Magnificent Jewels auction took in $81 million.

The auction was held a day after the Archduke Joseph Diamond fetched a world record price at an auction at Christie’s.