The 10.3-Carat ‘Mediterranean Blue’ Diamond Could Fetch $20 Million

The Mediterranean Blue: A Rare Gem Poised to Make Auction History

Sotheby’s is set to unveil one of the most extraordinary gemstones ever to grace the auction stage—The Mediterranean Blue. Weighing an awe-inspiring 10.03 carats, this Fancy Vivid Blue diamond stands as a testament to nature’s unmatched artistry and human craftsmanship. With its first-ever appearance on the market, this breathtaking gem is expected to fetch an estimated $20 million (CHF 18 million) at Sotheby’s High Jewelry Sale in Geneva on May 13, 2025.

A Rarity Beyond Compare

Certified by the Gemological Institute of America (GIA), The Mediterranean Blue has achieved the highest possible color grading for a blue diamond. Moreover, it belongs to the exceptionally rare Type IIb category, a classification that accounts for less than 0.5% of all diamonds worldwide. The cushion-cut shape further enhances its vibrant saturation, elevating it into an elite league among the world’s most exceptional diamonds.

An Exclusive Global Showcase

Before captivating bidders in Geneva, The Mediterranean Blue will embark on an exclusive world tour, commencing with a grand unveiling on April 8, 2025, at the Bassam Freiha Art Foundation on Abu Dhabi’s Saadiyat Island, a prestigious cultural hub. From there, the diamond will travel to Taipei, Hong Kong, and New York, offering collectors and connoisseurs an up-close look at this masterpiece before its highly anticipated auction.

A Legacy of Excellence

Quig Bruning, Sotheby’s Head of Jewelry, Americas & EMEA, underscored the diamond’s immense significance: “Any vivid blue diamond is a discovery worth celebrating, but one as entrancing as this—particularly over 10 carats—is a newsworthy event. Its remarkable size, charming cushion cut, and ocean-blue hue place it among the most important blue diamonds to appear on the market in recent years.”

Blue diamonds have long captivated collectors, connoisseurs, and historians. While the color blue symbolizes serenity, depth, and timeless beauty, its presence in diamonds is exceptionally rare. Only 0.3% of all diamonds analyzed by the GIA annually exhibit a predominantly blue hue, and of those, only a select few attain the coveted Fancy Vivid classification—making The Mediterranean Blue an indisputable marvel.

A Masterpiece Forged by Time and Expertise

The journey of The Mediterranean Blue began as a 31.94-carat rough diamond, discovered in 2023 at South Africa’s renowned Cullinan Mine—a legendary source of some of history’s most remarkable diamonds. The mine has yielded iconic gems such as The Great Star of Africa (530 carats), The Blue Moon of Josephine (12.03 carats, sold for $48.5 million in 2015), and The De Beers Blue (15.10 carats, sold for $57.5 million in 2022).

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 $48.5 million (more than $4 million 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 $57.5 million in 2022 at Sotheby’s Hong Kong.

“The De Beers Millennium Blue” diamond, a 10.10-carat oval-shaped, internally flawless gem, was sold at Sotheby’s Hong Kong in April 2016 for $31.8 million.

The 14.62-carat “Oppenheimer Blue,” holds the world auction record for a fancy vivid blue diamond of $57.5 million. It was sold by Christie’s in the May 2016 auction in Hong Kong.

A Diamond Destined for History

With its peerless color, exceptional size, and breathtaking brilliance, The Mediterranean Blue is poised to become one of the most significant diamonds ever auctioned. Collectors, investors, and jewelry aficionados worldwide will turn their attention to Geneva on May 13, as this unparalleled treasure finds its new custodian.

Following a year-long study, master artisans embarked on a six-month cutting and polishing process, ensuring the diamond’s optimal brilliance. The result: a cushion-modified brilliant cut, featuring kite-shaped and triangular facets that amplify its mesmerizing fire and sparkle. This precision cutting not only enhances its radiance but also preserves its extraordinary color intensity, solidifying The Mediterranean Blue as both an eternal relic and a modern masterpiece.

Will The Mediterranean Blue shatter auction records? Only time will tell—but one thing is certain: this masterpiece is already an icon.

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