The gem, set in a ring by Cartier that is estimated at $15 million–$25 million, will be auctioned in Geneva on Nov. 16

Sotheby’s will auction the Sky Blue Diamond, a 8.01 ct. fancy vivid blue diamond mounted in a ring by Cartier, at its Magnificent Jewels and Noble Jewels sale Nov. 16 in Geneva.

The ring is estimated to sell for $15 million–$25 million. It has received a rating of fancy vivid blue by the Gemological Institute of America—the highest possible color grading for a blue diamond.

“The Sky Blue Diamond is of a wonderfully clear celestial blue, presented in an extremely elegant square emerald cut—in my view, the most flattering of all the cuts for a colored diamond,” David Bennett, worldwide chairman of Sotheby’s international jewelry division, said in a statement  “This important gem will, I am sure, captivate all collectors of exceptional gemstones.”

The gem will be on display in London at the Sotheby’s Bond Street Galleries Oct. 13–17.

In November 2015, Sotheby’s set the record for the most expensive diamond ever sold at auction with a 12.03 ct. blue diamond that sold for $48.5 million.

(Photo courtesy of Sotheby’s) 

JCK