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.”
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