GENEVA, 13 MAY 2025 – “The Mediterranean Blue”, a supremely rare and exceptional Fancy Vivid Blue diamond weighing 10.03 carats, sold for CHF 17.9 million/ US $21.5 million during Sotheby’'S sale of High Jewelry in Geneva. The diamond attracted enormous interest and was pursued by two determined bidders, taking it – over the course of a nearly three-minute bidding battle – from an opening bid of CHF 9 million to its final price, finally selling to a client on the phone represented by Frank Everett, Vice Chairman of Jewelry, Americas, on behalf of an American private collector keen to add the blue diamond to her collection.
The Mediterranean Blue, a brand-new blue diamond only mined last year from the legendary Cullinan mines of South Africa, has generated huge excitement within the diamond industry and around the world since its announcement in March. Ahead of its final showing in Geneva, the diamond was spectacularly unveiled as part of Sotheby’s debut exhibition in Abu Dhabi, where it was showcased alongside seven extraordinary diamonds and gemstones, collectively worth well over $100 million. Its subsequent tour across the Middle East, Asia, and the United States only heightened anticipation among collectors and connoisseurs, leading to today’s sensational sale.
Commenting on the sale of The Mediterranean Blue, Quig Bruning, Sotheby’s Head of Jewelry, Americas & EMEA, and auctioneer of tonight’s sale, said:
“It has been an extraordinary honour to have been entrusted with the early destiny of the only fancy vivid blue diamond of this size and calibre to be offered on the market in some time. It is undoubtedly the defining stone of the season and ranks among the top blue diamonds we have sold. To witness the excitement it has generated throughout its global exhibition tour, culminating in today’s result, clearly reflects the growing global appetite for rare and impeccable diamonds, and a marked flight to quality among collectors who continue to seek the very best in the world.”
The Mediterranean Blue Diamond Sale Topped An Electrifying Auction
The Mediterranean Blue diamond was the highlight of Sotheby’s High Jewelry auction in Geneva, concluding an extraordinarily healthy CHF 42 million sale total with a 99% sell-through by value and 97% by number of lots sold. The auction was marked by extremely strong results for colored diamonds and gemstones and high participation of bidders and buyers from the USA, who were the majority group in both categories. Blue proved to be the standout hue of the day, with two additional blue diamonds finding eager buyers. Among them was a 5.83-carat fancy light blue diamond ring, which achieved an above-estimate price of CHF 1.2 million (Lot 596), and a 4.05-carat Fancy Blue diamond pendant necklace that sold for CHF 952,500 (Lot 573). The second most valuable lot of the sale was a magnificent pair of unmounted cushion-shaped diamonds, weighing 23.88 and 23.76 carats respectively (Lot 597), which realized CHF 3,222,000. Rounding out the top five lots was a superb diamond necklace/brooch combination by Van Cleef & Arpels (Lot 601) sold for CHF 1,079,500, achieving more than three times its low estimate.
About the Mediterranean Blue
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Colour Grade: Fancy Vivid Blue
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Weight: 10.03 carats
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Clarity Grade: VS2
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Shape and Cutting Style: Cushion Modified Brilliant
In addition to receiving the highest possible colour grading for a blue diamond from the Gemological Institute of America (GIA), The Mediterranean Blue has been found to be Type IIb, a classification which represents less than 0.5% of all diamonds.
Fashioning any coloured diamond is a challenging task, requiring numerous decisions to balance the largest possible size, the best clarity, and the most vibrant face-up color. The 31.94 carat rough diamond, which yielded The Mediterranean Blue, was studied for over a year after its discovery in South Africa in 2023. After a meticulous planning and cutting process lasting six months, the Mediterranean Blue was shaped into a cushion modified brilliantly, honoring the gem’s status as both a timeless relic and a contemporary masterpiece. Such a shape lends a soft, refined look, while the carefully positioned triangular and kite-shaped facets – characteristic of the brilliant cut – reflect light to create the captivating sparkle that makes this diamond come to life.
Although admiration of the colour blue is widespread among the general public, encountering a blue diamond is an incredibly uncommon occurrence. The principal mine to produce blues in more recent times, but with decreasing regularity, has been the Cullinan mine in South Africa, where The Mediterranean Blue was discovered. Less than 0.1% of any diamonds sourced show any evidence of blue colour, and an infinitesimally small percentage of those are graded Fancy Vivid Blue. Cullinan has yielded many of the world’s most famous diamonds, including the 530-carat Great Star of Africa, the largest faceted colourless diamond in the world. Other extraordinary blues from the Cullinan mine include The Blue Moon of Josephine – a 12.03 carat cushion-shaped Internally Flawless Fancy Vivid Blue diamond that sold for US$48.5 million (US$4,028,941 per carat) at Sotheby’s Geneva in 2015, and more recently The De Beers Blue, a 15.10 step-cut Fancy Vivid Blue diamond, which sold for HK$451 million / US$57.5 million in 2022 at Sotheby’s Hong Kong.
Sotheby’s Communication Team
Geneva – BRUNO BARBA
New York – AMANDA BASS
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