There is a new world record for the sale of a postage stamp. It is for the one-of-a-kind, 1856 British Guiana One-Cent Magenta. The auction house Sotheby's sold it in New York for $9.48 million. It is the fourth time the stamp has broken the record. Sotheby's said the record would not be broken again, unless the same stamp came up for auction. A spokesman said: "That price will be hard to beat, and likely won't be exceeded unless the British Guiana itself comes up for sale again in the future." A former curator of stamps at the British Library said the sale was like buying the 'Mona Lisa'.

An anonymous buyer bought the stamp. It was last owned by an heir to the du Pont chemical fortune. He is currently in prison for killing an Olympic champion wrestler. A 12-year-old stamp collector first found the stamp in 1873. He sold it a few years later for about $50 in today's money – a lot back then. It has since had a dozen owners, including the French government. The Sotheby's spokesman was amazed at the stamp's popularity. He said: "This is the most valuable item in the world by weight. It's just a tiny piece of paper." He was happy a collector bought it and not an investor.