Editor’s Note
This article reports on the record-breaking auction of the “Mellon Blue” diamond for 22 million euros. The text has been edited for clarity and conciseness.
On Tuesday, November 11, 2025, an exceptional diamond known as the “Mellon Blue” was sold at auction for the staggering sum of 22 million euros. The diamond had long belonged to a figure in New York high society.
The famous auction house Christie’s, headquartered in London, recently had the opportunity to conduct such a sale. The “Mellon Blue,” a vivid blue 9.51-carat diamond set on a ring and of “exceptional purity,” is among the “most beautiful colored diamonds ever offered at auction,” according to Rahul Kadakia, International Head of Christie’s Jewelry Department, as reported by *Le Parisien* on Wednesday, November 12, 2025.
The stone was auctioned in Geneva on Tuesday, November 11, for a dizzying amount: 17.4 million Swiss francs, or 18.7 million euros, with a final price of just over 22.1 million euros including taxes. This is not the first time this stone, also known as the “Zoe Diamond,” has been sold, as a person purchased it for $32.6 million (28 million euros) at Sotheby’s in New York in 2014. The stone, having “exceptional purity” according to Christie’s, was sold within the auction house’s estimates.
The “Mellon Blue” belonged to a figure of New York high society who possessed the pear-cut precious stone for decades. She had it mounted as a pendant. Rachel Lambert Mellon, known as “Bunny,” was a renowned American horticulturist, philanthropist, and art collector, notably known for redesigning the White House Rose Garden in 1961 at President Kennedy’s request. The diamond was sold after her death. The first buyer had even reworked it to enhance its clarity before parting with it.
Source: *Le Parisien*, 11/12/2025: A stone “of exceptional purity”: the “Mellon Blue” diamond and its 9.51 carats sold at auction for 22 million euros.
