[Lee Stewart]

A watch by Swiss luxury brand Patek Philippe has sold for over $31 million, the highest price ever paid for a timepiece at auction.

The Grandmaster Chime 6300A-010 has never been worn -- it was created specially for Saturday's auction in Geneva to raise money for research into Duchenne muscular dystrophy, according to Christie's.

It is the only version of the timepiece ever produced in stainless steel and the alarm sub-dial is marked with a special inscription, "the only one."

The watch has a reversible case in black and rose gold, 18-karat solid gold dial plates and is fixed with a band made of black, hand-stitched alligator leather.