'Mellon Blue' diamond ring sells for $25 million in Geneva auction

A vivid blue diamond weighing 9.51 carats and previously belonging to Rachel "Bunny" Mellon, the aristocratic philanthropist and a close friend of Jacqueline Kennedy, sold in Geneva for $25 million, Christie's auction house said on Tuesday.

The internally flawless pear-shaped diamond mounted at the tip of a swirling ring design is named the "Mellon Blue," after its former owner who had it set as a pendant. It sold for $32.6 million in 2014, the year Mellon died at the age of 103.

That was the highest price at the time ever paid for a coloured diamond at auction, Christie's said. But the world record for a blue diamond is the "Oppenheimer Blue," which sold for over $57 million in Geneva in 2016.

Mellon, an avid, self-taught horticulturalist, came from a wealthy background and married into the Mellon banking family.

One of her legacies was a redesign of the White House Rose Garden during the Kennedy administration, which U.S. President Donald Trump again renovated this year.