A "die error" coin means the coin is effectively a misprint, and though it made it into circulation it's a rare find and ...

Coin collection is big business for those ... Francisco facility and a single Denver mint specimen. These rare wrong planchet errors began to surface in circulation in the late 1940s, confounding ...

blank pieces of metal used to make coins. Planchet errors mean they might have the wrong shape or thickness, or no engraving at all Strike errors: A coin’s “strike” refers to the step in the ...