Rarity: Unique

Variety Equivalents: Pollock 3 

Significant examples:
In the February 2005 issue of NUMISMATIST (page 63), William Anton offered a 1792 "George Washington President" Birch Cent for an undisclosed price, describing it as follows: "Unique Birch Cent.  Gem Proof Condition.  The National Collection in Washington, D.C. has every American coin in its cabinet except this coin = A candidate for the world's most valuable numismatic item.  Considered Martha Washington on obverse and very first of the 1792 Mint Patterns struck."

Sources and recommended reading:
"United States Pattern, Experimental and Trial Pieces" by J. Hewitt Judd, M.D.

"United States Patterns and Related Issues" by Andrew Pollock