Editor’s Note
This article details the record-breaking $21.5 million sale of the ‘Mediterranean Blue’ diamond at Sotheby’s Geneva, highlighting the intense bidding and extraordinary value of this rare gem.
The Mediterranean Blue, an extremely rare and exceptional 10.03-carat Fancy Vivid Blue diamond, was sold for $21.5 million at a high jewelry auction at Sotheby’s in Geneva. With each carat weighing approximately 2 grams, the diamond sold for $10.75 million per gram. The sale concluded after a fierce bidding battle lasting nearly three minutes between two bidders. The winning bidder was a telephone bid, represented by Frank Everett, Vice President of Jewelry Americas, who bid on behalf of a private American collector wishing to add the blue diamond to her collection.
Quig Bruning, Head of Jewelry at Sotheby’s for the Americas and EMEA region, and auctioneer for the Geneva sale.
The Mediterranean Blue was mined last year from the legendary Cullinan mines in South Africa and has generated significant interest in the diamond industry and worldwide since its announcement in March. Before its final exhibition in Geneva, the diamond was showcased at Sotheby’s in Abu Dhabi, alongside seven other diamonds and gemstones, with a total value exceeding $100 million. Its subsequent tour of the Middle East, Asia, and the United States only heightened the anticipation among collectors and connoisseurs. In addition to receiving the highest possible color grade for a blue diamond from the Gemological Institute of America (GIA), the Mediterranean Blue was classified as a Type IIb diamond, a category representing less than 0.5% of all diamonds. The stone’s cushion shape accentuates its exceptional saturation, placing it in an exclusive category, even among the world’s finest diamonds.
Creating a colored diamond is a complex task, requiring numerous decisions to find the right balance between the largest possible size, the best clarity, and the most vivid color. The 31.94-carat rough diamond from which the Mediterranean Blue was created was studied for over a year after its discovery in South Africa in 2023. After a meticulous six-month planning and cutting process, the diamond was cut into a modified cushion brilliant shape. This shape creates a soft and refined appearance, while the carefully placed triangular and kite-shaped facets, characteristic of the brilliant cut, reflect light to create sparkle.
Finding a blue diamond is extremely rare. The primary mine producing them recently, albeit with decreasing regularity, is Cullinan in South Africa, where the Mediterranean Blue was discovered. Less than 0.1% of mined diamonds show traces of blue, and a tiny percentage of those are graded Fancy Vivid Blue. Cullinan has produced several of the world’s most famous diamonds, including the 530-carat Great Star of Africa, the world’s largest faceted colorless diamond. Among other exceptional blue diamonds from the Cullinan mine are the Blue Moon of Josephine, a 12.03-carat, internally flawless, cushion-cut vivid blue diamond sold for $48.5 million ($4,028,941 per carat) at Sotheby’s Geneva in 2015, and more recently the De Beers Blue, a 15.10-carat step-cut vivid blue diamond sold for HK$451 million ($57.5 million) in 2022 at Sotheby’s Hong Kong.