10-Carat Fancy Vivid Blue Diamond Expected to Sell for $20M
Dubbed the “Mediterranean Blue,” this “remarkably rare” diamond will be part of Sotheby’s May jewelry auction in Geneva.

“The Mediterranean Blue” will make its auction debut at Sotheby’s High Jewelry sale in Geneva on May 13, estimated to sell for about CHF 18 million ($20 million).
The diamond is classified as Type IIb and its color grade, fancy vivid blue, is the Gemological Institute of America’s highest possible color grading for a blue diamond.
According to GIA, only 0.3 percent of all diamonds submitted to the lab annually display a color that would be described as predominately blue, and of those, only a small number are fancy vivid weighing 10 carats or more.
“Like its namesake, the Mediterranean Blue is a symbol of nature’s eternal wonders. Its physical beauty, enhanced by the skill of a master cutter, is mesmerizing as is its blue color, so rarely seen,” GIA said.
“The attributes of the Mediterranean Blue, weighing 10.03 carats in the most coveted fancy-color range, are absolutely exemplary for a diamond.”
As for the shape, colored diamonds require careful planning to balance the largest possible size, the best clarity, and the most vibrant face-up color, Sotheby’s said.
The Mediterranean Blue is a cushion modified brilliant-cut diamond, the result of a six-month long planning and cutting process.
Sotheby’s said the diamond’s shape accentuates its saturation and places it in a “rarefied category,” even among the world’s most beautiful diamonds.
The 31.94-carat rough diamond that yielded The Mediterranean Blue was studied for more than a year after Petra Diamonds recovered it from the Cullinan mine in South Africa.
The mine has been the principal deposit to produce blues in more recent times, though with decreasing regularity, and it has yielded a number of famous diamonds.
Among them are the rough that yielded the 530-carat Great Star of Africa, the largest faceted colorless diamond in the world; The Blue Moon of Josephine, a 12.03-carat cushion-shaped internally flawless fancy vivid blue diamond that sold for $48.5 million at Sotheby’s Geneva in 2015; and the De Beers Blue, a 15.10-carat step-cut fancy vivid blue diamond, which sold for HK$451 million ($57.5 million) in 2022 at Sotheby’s Hong Kong.
The Mediterranean Blue will be unveiled April 8 at a special exhibition in Abu Dhabi, Sotheby’s first public exhibition in the United Arab Emirates’ capital city since 2009.
The event will take place at the Bassam Freiha Art Foundation, a nonprofit institution located on Saadiyat Island’s Cultural District.
Following the event, the diamond will be showcased in Taipei, Taiwan; Hong Kong; and New York before its exhibition and sale in Geneva in May.
“The Mediterranean Blue represents one of nature’s rarest gems. Any vivid blue diamond is a discovery worth celebrating, but one as entrancing as this, particularly being over 10 carats, is a newsworthy event,” said Quig Bruning, head of Sotheby’s Jewels, Americas, & EMEA.
“The Mediterranean Blue’s remarkable size, charming cushion-cut, and ocean-blue color places it in the rarefied company of some of the most important blue diamonds to come to market in recent years.”
The Latest

Dallow will lead the International Colored Gemstone Association, effective July 6.

Senior Editor Lenore Fedow headed to Savannah to learn more about the 10-year, $10 million partnership between JM and the art school.

Its new capsule jewelry collection features gold-finished stainless steel pieces designed for a maximalist look without a luxury price tag.

Colored gemstones, artisan finishes, mixed metals, and meaningful details are shaping demand in bridal jewelry.

The week-long event in Geneva is slated for April 2027.


The three industry leaders bring financial, communications, and legal expertise to the nonprofit’s board of directors.

Jewelers are missing out by not offering this one key add-on at the online point of sale, Emmanuel Raheb writes.

DCA is preparing the next generation of professionals by supporting workforce development, leadership growth, and career advancement.

The fourth collaborative collection from the retailer and jewelry content creator focuses on gemstone charms and strands of colorful beads.

This year’s AGTA Spectrum & Cutting Edge Awards will feature two new categories.

The collection features traceable alexandrite from Brazil in calibrated sizes that is sorted by grade.

Dhaval Raja has been appointed to the role.

The capsule collection looks to vintage trunk pins that echo the spirit of speed, freedom, and the mythology of the American road trip.

SSEF issued a notice about the potential new source of the sought-after gemstone, citing “credible reports” from trade sources.

As Amazon Prime Day kicks off, Etsy is encouraging shoppers to support small businesses.

Cole Winward is the recipient of 2026 AGA Gemological Scholarship.

Whether they evoked nostalgia, wonder, or laughter, these jewels put a smile on our faces.

Scheduled for April 2027, Basilia will be the first watch and jewelry trade show held in Basel since the collapse of Baselworld in 2020.

Submissions for the milestone 25th annual Gem Awards will be accepted across three categories from now through July 31.

The beloved beagle dons his aviator outfit for the new Engineer Master II Snoopy Flying Ace timepiece.

She wore the “Le Cauri Endiamanté” earrings, our Piece of the Week, in the Obamas’ first dual portrait for the Obama Presidential Center.

Couture’s Michelle Orman joins Amanda Gizzi and Michelle Graff for this special post-Market Week episode of My Next Question.

The lab is seeing emeralds with filler added post-testing enter the market, accompanied by reports that indicate little to no treatment.

The third generation of the Stern family to head Patek Philippe, he navigated the “quartz crisis” and preserved the brand’s independence.

The Texas-based jeweler is gradually rolling out a new experience-forward layout in its stores.

The Super Bowl LX champions were honored with diamond and blue sapphire rings by Jason of Beverly Hills.

Marianna Smirnova previously spent a decade working with the Responsible Minerals Initiative, in addition to other relevant roles.


























