A rare square 37-carat emerald owned by the Aga Khan fetched nearly $9 million at auction in Geneva on Tuesday, making it the world's most expensive green stone. Sold by Christie's, the Cartier ...
A rare square 37-carat emerald owned by the Aga Khan has fetched nearly $9million (£7million) at auction in Geneva, making it the world's most expensive green stone. The Cartier diamond and ...