GENEVA.- A Christies employee presents an unmounted heart-shaped diamond, D colour, internally flawless, type IIa diamond, weighing 56.15 carats, polished and symmetrical, during a press preview in Geneva, Switzerland, 01 April 2011. The gemstone is estimated to fetch between 9.000.000 and 12.000.000 Swiss Francs (6.920.000 and 9.230.000 Euro) at the Christies jewels sale on 18 May 2011 in Geneva. EPA/CHRISTIAN BRUN.

GENEVA.- A Christies member of staff displays an unmounted heart-shaped D colour, Internally Flawless, Type IIa diamond weighing 56.15 carats during an auction preview in Geneva April 1, 2011. The item is expected to sell between CHF 9,000,000 and 12,000,000 (US$ 9,000,000 and 12,000,000) when it goes into auction May 18, 2011 in Geneva. REUTERS/Denis Balibouse.