A rare 603 carat white diamond sold for $12.36 million is displayed during a news conference in Antwerp, October 9, 2006. The diamond, the ‘Lesotho Promise’, will be  resold for an expected $20 million. (Francois Lenoir/Reuters)

A model displays a rare 603 carat white diamond sold for $12.36 million during a news conference in Antwerp, October 9, 2006. The diamond, the ‘Lesotho Promise’, will be  resold for an expected $20 million. (Francois Lenoir/Reuters)

A model displays a rare 603 carat white diamond sold for $12.36 million during a news conference in Antwerp, October 9, 2006. The diamond, the ‘Lesotho Promise’, will be resold for an expected $20 million. (Francois Lenoir/Reuters)