'Bleu Royal', a 17.61 carats vivid blue diamond, set to dazzle in Geneva auction

"Bleu Royal", a rare 17,61 carats internally flawless fancy vivid blue pear shaped diamond. Photo: AFP

The exceptionally rare Bleu Royal gem is set to become one of the most expensive diamonds ever sold by auctioneers Christie's when it goes under the hammer on Tuesday (Nov 7).

The Bleu Royal is the star lot in a series of sales in Geneva this month which feature items from movie history including pearls worn by Audrey Hepburn and Marlon Brando's self-engraved watch.