Rare British Guiana stamp set for New York auction (BBC) {world's most valuable stamp?}

An exceedingly rare 19th Century postage stamp from a British colony in South America is expected to fetch a record sum at auction.

The 1856 British Guiana One-Cent Magenta could sell for $20m (£11.8m) at Sotheby's in New York on Tuesday.

The stamp has been sold three time before, each time setting the auction record for a single stamp.

It measures just 1in by 1in (2.5cm by 3.2 cm), and has not been publicly exhibited since 1986.

"Every collecting area has its Holy Grail. For stamps it is The British Guiana," Sotheby's wrote on its website, adding the stamp is often described as the "most famous" and "most valuable" in the world.



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more: http://www.bbc.com/news/world-us-canada-27890106