The British Guiana One-Cent Magenta postage stamp sold for USD 9.5 million, making it both the world's most expensive stamp and the most valuable object by weight and size - measuring just one-inch by one-and-a-quarter-inch.
No stamp is rarer than the sole-surviving example of the British Guiana, a unique yet unassuming penny issue from 1856, which has been heralded as the pinnacle of stamp collecting for more than a century, according to the auctioneer Sotheby's New York.
The stamp was sold to an anonymous telephone bidder.
David Redden, Sotheby's vice chairman, called the sale "a truly great moment for the world of stamp collecting."
More From This Section
"That price will be hard to beat, and likely won't be exceeded unless the British Guiana comes up for sale again in the future," Redden said in a statement.
The One-Cent Magenta was sold by the estate of John du Pont, heir to the du Pont chemical family, who died in prison in 2010, 13 years after being convicted of third degree murder for shooting to death his friend David Schultz, an Olympic gold medal-winning wrestler, 'The Telegraph' reported.