The pieces referred to by the catch-all title of "patterns" are among the rarest coins ever struck in the United States Mint.  There have been many attempts to define the U.S. pattern coin family as a whole.  While there are still a few exceptions, we believe that the definition included in the preface to the ninth edition of the book United States Pattern Coins: Complete Source for History Rarity, and Values by Dr. J. Hewitt Judd is the among the most comprehensive ever offered.  According to this definition, "A pattern coin is one that was struck at the Philadelphia Mint (with a few exceptions) for purposes of testing a design or concept, or perhaps from unusual die pairs, or in unusual metals, or to create delicacies for collectors, but which differs from normal circulation coins of standard design, date, and metal."  As a rule, patterns are exceedingly rare coins.  Their original mintages are unknown, although the number of pieces extant, as well as the reasons for their striking, suggest that very few specimens were prepared.  Indeed, most patterns were produced to the extent of only a handful of coins.  Patterns also offer considerable opportunity for continued study, as the circumstances surrounding the striking of many types and issues remain shrouded in mystery.