A mysterious necklace laden with some 500 diamonds and with possible links to a scandal that contributed to the downfall of Marie Antoinette, sold for $4.8 million at an auction in Geneva Wednesday. Sotheby's said it was likely that some of the diamonds featured in the piece came from the famous necklace from the scandal that engulfed Marie Antoinette just a few years before she was guillotined.

A rare square 37-carat emerald owned by the Aga Khan fetched nearly nine million dollars at auction in Geneva on Tuesday, making it the world's most expensive green stone.

The Aga Khan emerald has sold for $AU13.4 million at an auction in Geneva. The 37-carat gem was a gift from the Aga Khan Prince to his wife, Nina Dyer, in 1960, just five years before her death at age 30.