Planchet planchet is struck. After striking, it becomes a coin and is no longer a planchet. Occasionally, a planchet will escape the mint without having been struck. This is a blank planchet error, and is usually worth a few dollars for modern coins. Occasionally, blank planchets can be rare and valuable, such is the case for Morgan Dollar blank planchets, although authentication is highly recommended for such pieces as they would be fairly easy to counterfeit. Planchet A planchet \ˈplan-chət\ is a round metal disk that is ready to be struck as a coin. An older word for planchet is flan.
Eisenhower dollar proof planchets were to be used for uncirculated "blue Ikes", but these were placed in the bin for rejected copper-nickel proof planchets, intended to be shipped to be coined for circulation at Denver. The 1977 pieces resulted from pieces rejected for Bicentennial silver proof use, which were again placed in the wrong bin (they should have been melted, as the Mint was no longer striking silver uncirculated Eisenhower dollars). Between 10 and 20 of each date are known. Wexler, Crawford, and Flynn report an even rarer 1776–1976-D dollar in silver, but state that none have been offered at auction or