An extraordinarily rare Type I Alexandria Va. Postmaster's Provisional is to auction during a forthcoming four-day specialist sale scheduled for December 10-14 in New York.

One of only three Alexandria Postmaster's Provisional stamps known to be on complete covers, the stamp is a true star of world philately.

One of only six known examples in existence

The very fine example will lead the provisional section of the sale, being one of just six recorded examples of the stamp on buff paper. A Type II example of the stamp sold in March 2012 for $550,000 - a 450% increase on its $100,000 estimate - suggesting that this Type I example may also exceed its $500,000 valuation.

Provisional stamps are highly coveted by collectors as they predate the US' first official postage stamp, which was introduced in 1847. The issue was a method of prepayment for envelopes and stamps orchestrated by postmasters between 1845 and 1847 - this revered Alexandria Va. example has been dated August 25, 1846.

The offered cover was discovered in 1926 by Edward S Leadbeater of Alexandria, before being sold into the great Lapham Collection of Postmaster's Provisionals. Last sold in 1986, the sought after stamp achieved $77,000 - a 156.6% increase on its catalogue value of $30,000.

Here at Paul Fraser Collectibles we also have a fine array of stamps in stock, including rare examples from Great Britain and Hong Kong.