1109-carat diamond 'Lesedi La Rona', at Sotheby's auction house in London

A model posing with an uncut 1109-carat diamond named 'Lesedi La Rona', at Sotheby's auction house in London, on June 14, 2016. The world's largest uncut diamond failed to sell at auction in London on Wednesday as bids failed to reach its reserve price of over $70 million.