Super stones: The most expensive diamonds in the world (12)

The 31.06 carat Wittelsbach-Graff blue diamond is on display at the American Museum of Natural History in New York, the United States, Oct. 28, 2010. The diamond was bought by Laurence Graff at a Christie's auction in December 2008 in London for a record USD 24.3 million. (Xinhua/Shen Hong)