Why is the British Guiana stamp valuable?

It was issued by the British colony of British Guiana (now Guyana) in 1856, and only one copy of the one-cent stamp is known to exist. The stamp is also known as the "B.G. Magenta" or the "Magentas."

The British Guiana One-Cent Magenta became famous for its rarity and its distinctive colour. The stamp was printed on magenta paper instead of the usual white paper, which was an error. The error was discovered after only a few copies of the stamp had been printed and issued, and the remaining stamps were destroyed.

The British Guiana One-Cent Magenta was rediscovered in 1873 by a Scottish boy named Vernon Vaughan, who found it in an old album of stamps that belonged to his uncle. Vaughan sold the stamp to a local dealer for six shillings, and the dealer sold it to another dealer for £1. The stamp eventually found its way into the hands of a French stamp dealer named Alfred Caspary, who purchased it for £5,000 in 1878.

Caspary sold the British Guiana One-Cent Magenta to a British stamp dealer named Thomas Allen in 1911 for £10,000. Allen sold the stamp to a consortium of investors, which included King George V, for £17,000 in 1914. The consortium sold the stamp to a private collector, Frederick John Melville, for £35,000 in 1922. Melville died in 1935 and left the stamp to his son, Phillip Melville.

Phillip Melville sold the British Guiana One-Cent Magenta to a group of investors, including the American industrialist John du Pont, for £850,000 in 1970. The investors then sold the stamp to a private collector, John E. du Pont, for £1.2 million in 1980. John E. du Pont was convicted of murder in 1997, and the stamp was confiscated by the US Marshals Service. The government sold the stamp to Sotheby's, who sold it to an anonymous buyer for $9.5 million in 2014.

The British Guiana One-Cent Magenta is considered to be one of the most valuable stamps in the world because of its rarity and its historical importance.**