The Graff Imperial Blue diamond is a rare type IIb 39.81 carat pear-shaped IF fancy blue diamond.
It is believed to be the largest flawless fancy blue diamond in the world. It was discovered in recent years, from alluvial deposits.
The rough stone weighed 101.50 carat and was bought by Laurence Graff, who had it cut into its final state.
It was sold to an anonymous buyer after having been set in a platinum ring.