A piece of costume jewelry purchased for $15 contained a 26 carat diamond worth $454,000

Sotheby's LONDON (AP) -- Some people have all the luck. Consider the person who dropped about 10 pounds (about $15) around 30 years ago on what was thought to be a piece of costume jewelry -- it turned out to be a 26.27 carat white diamond. The gem bought at a flea market is expected to fetch about 350,000 pounds ($454,000) when it is auctioned by Sotheby's next month. The buyer had no idea of the ring's value because 19th-century diamonds were not cut to show off their brilliance and clarity. T...