Pear-shaped pink diamond sells for $31.6m

A rare pear-shaped vivid pink diamond fetched $31.6 million at auction on Tuesday, Sotheby's said, but several other large stones failed to reach the reserve prices set by the sellers.

The "Unique Pink", weighing 15.38 carats and mounted on a ring, sold to an unnamed Asian private collector bidding by telephone, the auction house said.

It was the star lot at the saleroom's semiannual auction in Geneva, with a pre-sale estimate of $28 million-$38 million.