Editor’s Note
This article reports on the record-breaking sale of the “Mellon Blue” diamond in Geneva, highlighting its provenance and the significant price achieved at Christie’s auction.
A 9.51-carat intense blue diamond, named the “Mellon Blue” and owned by American philanthropist and art collector Rachel “Bunny” Mellon, was sold in Geneva on Tuesday for USD 26.6 million, according to auction house Christie’s.
The sale took place during the traditional “Magnificent Jewels” auction at the Hotel des Bergues in the Swiss city, where the stone achieved a selling price of 20.5 million Swiss francs (USD 26.6 million) including commissions. This figure fell within the auction house’s own estimated range of USD 20 to 30 million.
The pear-shaped jewel, graded “Fancy Vivid Blue” and “Internally Flawless” by the Gemological Institute of America (GIA), was set in a serpentine-designed ring. For decades, it remained part of Mellon’s private collection, known for her closeness to Jacqueline Kennedy and her extensive philanthropy in American art circles.
In 2014, the same year Mellon passed away at 103, the diamond was publicly auctioned in New York for USD 32.6 million, which was then the highest price ever paid for a colored diamond at auction, according to Christie’s.
The world record for a blue diamond still belongs to the 14.62-carat “Oppenheimer Blue,” which was sold for over USD 57 million in Geneva in 2016.
Tuesday’s sale, while significant due to the gem’s pedigree, did not meet the expectations of some industry specialists. Tobias Kormind, Managing Director of online jeweler 77 Diamonds, noted in statements collected by Christie’s:
The executive attributed the result to a negative market environment, marked by “geopolitical tensions — from the war in Ukraine to Trump’s tariffs — and a weakened Chinese economy that kept many regular buyers away.” Kormind concluded:
In contrast, auctioneer Rahul Kadakia, Head of Christie’s Luxury Auctions Department, celebrated what he considered “a remarkable moment” for his team, stating it represents the “appetite of the elite among collectors for extraordinary and historic gems.”
Max Fawcett, Global Head of Jewelry at the auction house, stated last Friday prior to the event that the “Mellon Blue” stood out for not having been modified with additional facets, unlike many modern gems, and that its large shape and color made it “the gem of gems.”
Fawcett highlighted that, in addition to its exceptional technical characteristics, the diamond had functioned as a symbol of a lifestyle “characteristic of a golden age, only possible with a Gilded Age fortune.”
The bidding for the “Mellon Blue” took place during the first of two days of high jewelry auctions being held in Geneva this week.
Christie’s rival, Sotheby’s, will present tomorrow the 10.08-carat pink diamond “Glowing Rose,” graded “Fancy Vivid Pink.” The stone, named for its rarity and chromatic purity, will go on sale with an estimated price of around USD 20 million.
Concurrently, at Sotheby’s event, a brooch seized from Napoleon Bonaparte after his flight from the Battle of Waterloo in 1815 will be auctioned. The piece, set with old mine-cut diamonds, is estimated between USD 150,000 and USD 250,000.
Regarding the “Mellon Blue,” specialists like Kormind wonder if the “moderation” observed among sellers and buyers this week will be replicated during the rest of the season in Geneva, where the influence of international conditions seems to weigh significantly on the prices achieved by exceptional jewels.
