Editor’s Note
This article reports on the record-breaking $21.5 million sale of the rare “Mediterranean Blue” diamond at a Sotheby’s auction in Geneva.
On the evening of Tuesday, May 13, an exceptionally rare blue diamond was sold for a staggering $21.5 million at a Sotheby’s Magnificent Jewels auction in Geneva.
Named “The Mediterranean Blue,” the 10.3-carat “Fancy Vivid” blue diamond was the undisputed highlight of the auction, positioned as the final lot of the evening. Its pre-sale estimate was approximately $20 million.
The bidding lasted about two and a half minutes, starting at 9 million Swiss francs (about $10.8 million). After several intense rounds, the diamond was finally won by an anonymous American private collector via telephone for 17.9 million Swiss francs (about $21.5 million, including buyer’s premium and fees).
Sotheby’s stated that this magnificent gem was cut from a 31.93-carat rough diamond mined in 2023 from the Cullinan mine in South Africa. After a year of careful planning and six months of cutting, shaping, and polishing, the rough stone was transformed into a 10.3-carat cushion brilliant-cut diamond with VS2 clarity (no visible flaws or inclusions to the naked eye). It has been graded by the Gemological Institute of America (GIA) as a Type IIb diamond.
Since its debut in March, this rare blue diamond has caused a sensation in the diamond industry. It was first exhibited alongside seven other exceptional diamonds and gemstones at a Sotheby’s preview in Abu Dhabi, UAE, on April 8. It subsequently toured cities including Taipei, Hong Kong, and New York.
Among colored diamonds, only 0.3% exhibit a blue hue. Within that tiny fraction, only 1% achieve the “Fancy Vivid” color grade, making them exceptionally rare. “The Mediterranean Blue” is one such diamond.
The current world auction record for a blue diamond is still held by the 14.62-carat “Oppenheimer Blue,” which sold for $57.54 million in 2016.