Sotheby’s to Auction Exceptionally Rare 10.3-Carat Fancy Vivid Blue Diamond
Fancy vivid blue diamonds exceeding 10 carats are among the rarest gemstones in the world, and Sotheby’s is set to present one at its High Jewellery sale in Geneva on 13 May.
Known as “The Mediterranean Blue,” this extraordinary 10.3-carat fancy vivid blue diamond – the highest grading for a blue diamond – has been assessed by the Gemological Institute of America (GIA) with a VS2 clarity rating. It is also classified as a Type IIb diamond, a category that accounts for less than 0.5% of all diamonds, according to the auction house.
This cushion-shaped modified brilliant diamond is expected to be a highlight of the auction, with an estimated value of around $20 million.
“Any vivid blue diamond is a significant discovery, but one as mesmerising as this, especially over 10 carats, is truly newsworthy,” said Quig Bruning, Sotheby’s Head of Jewellery, Americas & EMEA. “The Mediterranean Blue’s remarkable size, elegant cushion cut, and striking ocean-blue hue place it among the most important blue diamonds to appear on the market in recent years.”
Before the auction, The Mediterranean Blue will be unveiled on 8 April at the Bassam Freiha Art Foundation in Abu Dhabi, a remarkable dune-shaped architectural structure. This non-profit institution, founded by philanthropist and art collector HE Bassam Said Freiha, houses an extensive collection of Orientalist art. The foundation is located on Saadiyat Island, home to renowned cultural landmarks such as the Louvre Abu Dhabi and the upcoming Guggenheim Museum. This marks Sotheby’s first public exhibition in Abu Dhabi since 2009, with further details on the unveiling to be announced in the coming weeks.
A Diamond of Remarkable Origin
Sotheby’s revealed that The Mediterranean Blue was cut from a 31.94-carat rough diamond, discovered in 2023 at the Cullinan mine in South Africa. The transformation into a finished gem involved a year of meticulous study, followed by six months of precise planning and cutting.
Blue diamonds of substantial size and exceptional quality rank among the most valuable gemstones ever sold at auction. In fact, two of the three most expensive diamonds ever auctioned were blue diamonds. Most of these rare gems originate from the Cullinan mine, which has produced some of the world’s most famous diamonds, including the 530-carat Great Star of Africa, the largest faceted colourless diamond ever discovered.
Historic Blue Diamonds from the Cullinan Mine
Other legendary blue diamonds sourced from the Cullinan mine include:
The Blue Moon of Josephine – A 12.03-carat, cushion-cut, internally flawless fancy vivid blue diamond, which sold for $48.5 million (over $4 million per carat) at Sotheby’s Geneva in 2015.
The De Beers Blue – A 15.10-carat, step-cut fancy vivid blue diamond, which fetched $57.5 million at Sotheby’s Hong Kong in 2022.
The De Beers Millennium Blue – A 10.10-carat, oval-shaped, internally flawless diamond, which sold for $31.8 million at Sotheby’s Hong Kong in April 2016.
The Oppenheimer Blue – A 14.62-carat fancy vivid blue diamond that holds the world auction record for a blue diamond at $57.5 million, sold by Christie’s in Hong Kong in May 2016.
According to the GIA, only 0.3% of all diamonds submitted for grading annually exhibit a predominantly blue colour, and of these, very few are classified as fancy vivid blue weighing over 10 carats.
“The attributes of The Mediterranean Blue, weighing 10.3 carats and sitting within the most sought-after fancy colour range, make it a truly exceptional diamond,” the GIA stated in Sotheby’s announcement.
This extraordinary gem is expected to draw significant attention from collectors and investors when it goes under the hammer in Geneva this May.