The rarest of items in philately have the following characteristics:
- Unique or extremely rare - e.g. British Guyana One Cent Magenta.
- Be genuinely used either on cover or extracted from cover. This is especially important as printers waste somehow enters into the philatelic market - e.g. Sweden's 3-skilling-banco "Error of Color".
- It should be of the first/early issue of a country. Clearly the early issues of a country have the most historical significance and ‘cache’ in comparison to the later issues. Also as for many countries, stamps of some of the later issues were printed to order for philatelists – e.g. Mauritius Post Office
- Last, but not the least it should have philatelic significance – e.g. The Dawson Hawaiian missionary cover .
Given the strict criteria above, there should be no doubt in anybody’s mind about the rarity of items satisfying the above conditions, not just in context of India but of the world of philately in general. Any item that satisfies all the above must be exceptionally rare/unique. A more detailed description is as follows,
The Dawson Hawaiian Missionary Cover of 1852 is the only known cover bearing a copy of the 2¢ Hawaiian Missionary issue. Also on the cover are a 5¢ Missionary and a pair of 3¢ stamps from the US 1851 issue. Seen on letters sent by missionaries in Hawaii, the stamps were printed at a newspaper plant in Hawaii. Last sold November 7, 1995 for $2,090,000 (inc. buyer’s premium) by Robert A. Siegel Auction Galleries
The "Treskilling" Yellow, or 3 skilling banco error of color, is a postage stamp of Sweden. In 1855, Sweden issued its first postage stamps, a set of five depicting the Swedish coat of arms, with denominations ranging from 3 to 24 skillings banco. The stamp was extracted from a cover found by a young collector in his grand mothers attic. In 1984 the stamp made headlines when it was sold by David Feldman for 977,500 Swiss francs. A 1990 sale realized over one million US$, then in 1996 it sold again for 2,500,000 Swiss francs
The British Guiana 1¢ magenta is among the rarest of all postage stamps. Issued in limited numbers in British Guiana (now Guyana) in 1856, only one specimen is now known to exist. It belonged to the Ferarry collection that was willed to a Berlin museum following Ferrary's death in 1917, but was taken by France as war reparations following the end of World War I. Arthur Hind bought it during the series of fourteen auctions in 1922 for over US$36,000 (reportedly outbidding three kings, including King George V), and it was sold by his widow for US$40,000 to a Florida engineer. In 1970, a syndicate of Pennsylvanian investors, headed by Irwin Weinberg, purchased the stamp for $280,000 and spent much of the decade exhibiting the stamp in a worldwide tour. John E. du Pont bought it for $935,000 in 1980, and it is believed to be locked away in a bank vault, while its owner is serving a 30-year sentence for murder.
The Mauritius Post Office postage stamps are amongst the rarest and most valuable stamps in the world. They are also known as the Blue Penny and the Red Penny. Their value is due to two factors — they were the first stamps of the British Empire to be produced outside the United Kingdom and in their initial issue were printed with the wrong wording. These first issues of Mauritius catalogue at over ₤500,000 (the Mints are rarer and un-catalogued and have recently sold in excess of a million pounds) with around 10-12 individual stamps in total known and mostly exhibited in museums.
The United States 1¢ Z grill is the rarest of all US stamps, with only two known to exist (of a thousand printed ). Last sold to Don Sundman of Mystic Stamp Company in October, 1998 as part of the Robert Zoellner collection for $935,000 (inc. buyer’s premium) by Robert A. Siegel Auction Galleries. Exchanged by Sundman on November 2, 2005 for the unique inverted Jenny plate block auctioned two weeks earlier for $2.97 million to Bill Gross.