A stunning 9.51-carat blue diamond, known as the ‘Mellon Blue,’ was sold for 20.5 million Swiss francs ($26.6 million) at a Christie’s auction in Geneva, Switzerland. The gem, named after the late American arts patron Rachel ‘Bunny’ Mellon, had been anticipated to fetch between $20 million and $30 million. The final price included the buyer’s premium and additional fees. Previously, the diamond was sold in 2014 for $32.6 million, marking one of the highest prices ever paid for a colored diamond at auction. The ‘Mellon Blue’ had been a prized possession in Mellon’s private collection for decades. Max Fawcett, Christie’s global head of jewelry, highlighted the diamond’s exceptional quality, describing it as a ‘gem of gems’ due to its Fancy Vivid Blue color and Internally Flawless grade, as certified by the Gemological Institute of America. The auction marked the beginning of a two-day jewelry event in Geneva, with Sotheby’s set to auction the ‘Glowing Rose’ pink diamond, expected to attract bids around $20 million.