The vivid blue diamond, known as "Bleu Royal" and set in a ring, is among the rarest ever to be unearthed. Max Fawcett, head of Christie's jewellery department in Geneva, said the diamond was unique because of its a deep rich blue colour and its unmodified pear brilliant shape. At its auction on Tuesday, Christie's sold dozens of rare jewellery pieces worth a combined total of more than $77 million. In a separate sale on Monday, Christie's sold a Rolex wristwatch worn by Marlon Brando in the 1979 movie "Apocalypse Now" for more than 4.5 million Swiss francs ($4.99 million). Two years ago, that same watch sold at auction for 2 million Swiss francs.

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Persons: Carola Chiadini, Denis, Rahul Kadakia, Max Fawcett, Christie's, Fawcett, There's, Marlon Brando, Cécile Mantovani, Gabrielle Tétrault, Farber, Jonathan Oatis Organizations: REUTERS, Thomson Locations: Geneva, Switzerland, GENEVA, America