rare mellon blue diamond 2025 sale christies 1234760992

A rare blue diamond pendant known as the Mellon Blue, owned by art collector Rachel Lambert “Bunny” Mellon, sold for $25.5 million at Christie’s Magnificent Jewels auction in Geneva on Tuesday. The 9.51-carat fancy vivid blue, internally flawless pear-shaped diamond had a pre-sale estimate of $20–30 million. This price is 22 percent less than the $32.6 million it achieved at Sotheby’s in 2014 as part of Mellon’s collection sale, and nearly 60 percent less when adjusted for inflation. The buyer was not disclosed.