A model wears a 50.05-carat heart-shaped D-Colour internally flawless diamond pendant at Sotheby's auction house in central London September 29, 2014. The diamond is expected to fetch between $7.7 million and $9 million at the auction house's Autumn Sale in Hong Kong on October 7, 2014. REUTERS/Stefan Wermuth (BRITAIN - Tags: SOCIETY ENTERTAINMENT)