Art collector Rachel Lambert “Bunny” Mellon’s blue diamond pendant, known as the Mellon Blue, has sold for $25.5 million on Tuesday at Christie’s Magnificent Jewels auction, held at the Four Seasons Hotel des Bergues in Geneva.
The price achieved today is 22 percent less than what the diamond sold for 11 years ago. Adjusted for inflation, it’s a drop of nearly 50 percent in value.
The 9.51-carat fancy vivid blue, internally flawless pear-shaped diamond, which Christie’s had given a pre-sale estimate of $20–30 million, last sold at auction in 2014 as part of Sotheby’s sale of Mellon’s collection, where it made $32.6 million, more than double its high estimate of $15 million. (Adjusted for inflation that $32.6 million would be around $44.7 million in 2025.)
According to a report in the New York Times at the time of the sale, the pendant sold to an “unidentified Hong Kong collector,” setting the world auction record for a blue diamond as well as a price-per-carat for any diamond.
The world auction record for a blue diamond has since been surpassed. In 2016, Christie’s sold the 14.62-carat Oppenheimer Blue for $57.5 million. In 2022, Sotheby’s sold the 15.10-carat De Beers Cullinan Blue, which also made $57.5 million.
Mellon, who died in 2014 at age 103, was heir to the Listerine fortune; her second husband, Paul Mellon, was an heir to the Mellon banking and oil fortune. At the 2014 Sotheby’s sale of her art collection, two Rothko paintings—Untitled (Yellow, Orange, Yellow, Light Orange), from 1955, and Untitled, from 1970—sold for a total of $76 million.
This past September, when the new sale was announced, Rahul Kadakia, Christie’s international head of jewelry, told Town & Country, “Bunny Mellon’s legacy as a tastemaker known for designing the White House Rose Garden and curating exceptional art and jewelry elevates the Mellon Blue’s allure by tying it to her sophisticated aesthetic and cultural prominence.”
A little primer on just how rare this type of diamond is, from Julie Brener Davich in an issue of Puck’s “Wall Power” newsletter back in September: “Blue diamonds are exceedingly rare, comprising less than 0.1 percent of all diamonds. And less than 1 percent of those can be categorized as fancy vivid.” (For the perhaps very small cross section of readers reading this article and also reading, or having read, the new Thomas Pynchon novel, Shadow Ticket, you might recognize Fancy Vivid as the name of a minor character with a “blindingly platinum cocktail bob.”)
Today’s was a hot sale—literally. Early in the auction, the auctioneer asked a Christie’s colleague to open the window to cool the air in the salesroom.
Correction, November 11, 2025: An earlier version of this article misreported the sale price for “Mellon Blue” diamond. It sold for $25. million, not $27.7 million.
