Rare 9.51-carat blue diamond auctions in Geneva

The auction house Christie's will be offering up a magnificent 9.51-carat vivid blue diamond on 12th November, known as "The Mellon Blue". The diamond is expected to fetch up to $30 million next week in Geneva. 

Fawcett, Christie's Global Head of Jewellery said  "It was first sold as part of the Mellon collection in 2014 for 32.6 million US dollars. It was bought by an Asian collector and today we have it back for sale with a pre-sale estimate of 20 to 30 million dollars."

The stone, set on a pendant, once belonged to Rachel Lambert Mellon, better known as Bunny Mellon, an American horticulturalist, philanthropist and art collector. The diamond was last seen publicly in 2014, when it was offered at auction in New York after her death, for more than $32 million.