There was a $13.6m raid on a Graff store in the UAE back in April:
http://www.ameinfo.com/116950.html
"All branded diamonds like Graff are certified diamonds and they also have lazor inscriptions in the girdle of every piece. But besides these trademarks Graff diamonds are exquisite solitaries and coloured diamonds, therefore, they can be easily distinguished, making it impossible to sell them in the UAE market.” He added that even if they are moved out of UAE, it will be a difficult task to sell them.
Experts also say that in the UAE, all diamonds can only be sold if there is an invoice, a law that is very important to protect the diamond trade."