In fact, blank coins are not uncommon due to errors during the minting process. If you see one, hold on to it — it could be worth hundreds of dollars on the collectible coins market. Discover ...

This particular "quarter" is among the rarest of its kind. One, it's a double-denomination, and what's more, it's a proof ...

Planchet errors: Planchets are the round, blank pieces of metal used to make coins. Planchet errors mean they might have the wrong shape, wrong thickness and have no engraving at all Strike errors ...