Rare ‘Mellon Blue’ diamond is expected to fetch up to $30 mn at Christie’s Geneva auction on Nov 11, 2025

A rare 9.51-carat Fancy Vivid Blue diamond known as “The Mellon Blue” is set to headline Christie’s Geneva auction on November 11, with an estimated sale price of $20–30 million.

Once owned by American heiress and style icon Bunny Mellon, the pear-shaped gem is considered one of the finest blue diamonds ever graded.

Sotheby’s will follow with the sale of the 10-carat “Glowing Rose” pink diamond and royal jewels linked to Napoleon, marking one of Europe’s most prestigious luxury auctions of the year.