Blue diamond expected to dominate November auction

A blue fancy colour diamond is headed to auction in Geneva in November with an eye-popping price tag.

The headline of the 11 November Magnificent Jewels sale, hosted by Christie’s in Geneva, will be the Mellon Blue.

Set in a ring, the stone is a 9.51-carat fancy vivid blue diamond that is internally flawless. It will enter the auction with an estimated return of around $USD30 million ($AUD45.7 million).

The diamond was once set in a pendant and belonged to Rachel Lambert Mellon, a horticulturist, philanthropist and art collector.

Mellon’s grandfather, Jordan Lambert, was the inventor of Listerine. Highly regarded, Mellon’s garden designs can be seen at the White House.

The diamond was sold for $USD32.6 million at Sotheby’s in 2014, setting a world record price for a blue diamond. Christie’s will preview the Mellon Blue in Saudi Arabia, Shanghai, Hong Kong, Bangkok, and New York before the auction in November.