The oldest diamond ever to be sold at auction, fetched $9.7million yesterday at Sotherby's auction house in Geneva.

The 35 carat Beau Sancy diamond had been passed among the royal families in France, England, Prussia and the Netherlands. David Bennett, one of the sellers at Sotheby’s, said: “The Beau Sancy is one of the most fascinating and romantic gems ever to appear at auction. One client I showed it to was moved to tears by it.”

The pear-shaped diamond’s royal connections date back to 1604, when it was bought for Henri IV of France at the insistence of his wife Marie de Medici who wore it atop her crown at her coronation. Later that century it was acquired by the Dutch and used to seal the wedding of Willem II of Orange Nassau to Mary Stuart, daughter of Charles I of England. Stuart pawned the rose-cut gem to finance her brother Charles II’s fight for the throne.

It historic jewel was sold by the Royal House of Prussia, the line of descendants that once ruled Prussia. Five bidders fuelled the price of the jewel, said to be the oldest diamond sold at auction, before it was purchased by an anonymous bidder.