This Is the Most Expensive Diamond of All Time 10.79K Max Read 11/17/10 02:07AM Filed to: the rich the rich Diamonds Jewels Pink diamond Auctions Money Appic Tweetg Fb This 24.78-carat "fancy intense pink" diamond just sold for $46 million at a Swiss auction, making it the most expensive jewel ever sold. It's okay, though! The birthstone necklace you bought at a truck stop is very pretty, too.