What credit crunch? At Christie's in Central London, the Wittelsbach diamond became the most expensive stone or piece of jewelry ever sold at an auction. Back in 1664, this sky-blue gem was given as the wedding dowry of a Spanish princess “Infanta..

While the largest D-color flawless diamond went for nearly £8 million at Sotheby’s last year, Christie’s might see a diamond being sold out for as much as £10 million when it goes on sale in London on December 10. This extraordinary blue-gray...