A giant 709-carat diamond unearthed in Sierra Leone has sold at auction in New York for $6.5m (£4.8m). Laurence Graff, chairman of Graff Diamonds, won the precious stone - nicknamed the "peace ...

Graff Diamonds A team of cutters will work out ... state-of-the-art 3D equipment that searches for inclusions - small imperfections in the heart of the stone - to decide how the diamond will ...