Editor’s Note
A rare blue diamond named “The Mediterranean Blue” has set a new benchmark at auction, fetching $21.5 million from a private collector. This sale underscores the enduring allure and significant value of exceptional gemstones in the high jewelry market.
A rare 10.03-carat cushion-cut fancy vivid blue diamond named “The Mediterranean Blue” was sold for $21.5 million at Sotheby’s High Jewelry auction in Geneva on Tuesday. The diamond, with VS2 clarity, was purchased by a private American collector through a phone bid.
The final price slightly exceeded the pre-sale estimate of approximately CHF 18 million ($20 million). Sotheby’s described the diamond as “one of the most important blue diamonds to come to market in recent years” and the most valuable diamond or jewel sold by the auction house so far this year. The bidding opened at CHF 9 million ($10.7 million) and sparked a nearly three-minute battle between two bidders.
“The Mediterranean Blue” is a Type IIb diamond, a category representing less than 0.5 percent of all diamonds. Its fancy vivid blue color grade is the highest possible rating from the Gemological Institute of America for a blue diamond. Less than 0.1 percent of diamonds exhibit any blue color, with an even smaller fraction achieving the fancy vivid blue grade.
The 31.94-carat rough diamond was mined in 2023 from the Cullinan mine in South Africa. After over a year of study and a six-month cutting process, it was fashioned into a cushion modified brilliant cut to maximize its size, clarity, and vibrant face-up color. Sotheby’s stated this cut honors the stone as “a timeless relic and a contemporary masterpiece.”
Prior to the auction, the diamond was unveiled at Sotheby’s debut exhibition in Abu Dhabi and toured the Middle East, Asia, and the United States. In the U.S., jewelry designer Lauren Harwell Godfrey created a brooch design inspired by the Met Gala theme, though the diamond was ultimately presented and sold set in a ring.
The Geneva High Jewelry auction achieved a total of CHF 42 million ($49.8 million), with a 99% sell-through rate by value. Sotheby’s reported “extremely strong” results for colored diamonds and gemstones, with strong participation from U.S. bidders and buyers. Other notable sales included a pair of unmounted cushion-shaped diamonds (23.88 and 23.76 carats) for CHF 3.2 million ($3.8 million), a 5.83-carat fancy light blue diamond ring for CHF 1.2 million ($1.4 million), and a 4.05-carat fancy blue diamond pendant necklace for CHF 952,500 ($1.1 million).
