Editor’s Note
The upcoming auction of the “Mellon Blue” diamond highlights the enduring allure and staggering valuations within the world of ultra-rare gemstones. While its anticipated price is extraordinary, it serves as a point of comparison to even more legendary sales, reminding us of the unique stories and extreme rarity that drive this rarefied market.
“Mellon Blue” Diamond Expected to Fetch $30 Million at Auction
One of the purest and most expensive diamonds will be auctioned at the November sale in Geneva. However, it is far from being the most expensive diamond ever sold at auction. An overview:
The “Mellon Blue” diamond is to be auctioned in Geneva with an estimated value of $20 to $30 million.
The 9.51-carat, flawless diamond in the “Fancy Vivid Blue” color is one of the rarest and most expensive pieces of jewelry.
The diamond once belonged to American philanthropist Bunny Mellon and has a long, mysterious history.
Blue diamonds are extremely rare, accounting for less than 0.2 percent of all diamonds, which increases their demand.
The “Mellon Blue” is not the most expensive diamond; the “Pink Star” holds the record with a sale price of 71.2 million euros.
© AFP/Peter Parks
The “Mellon Blue” Diamond
© AFP/Peter Parks
Tina Furtner-Hanisch
Editor News & Social Media
Editor News & Social Media
November 9, 2025, 16:25
