You don’t usually see errors with proof coins, but there are exceptions. One involved 1975 dime proof sets, which that lacked an “S” mintmark (from the San Francisco Mint). So far ...

Buyers interested in the final Proof set of copper-nickel clad American Women quarter dollars in that four-year program can ...

You never know when you might come across a valuable error coin, so it helps to know what to look for. Error coins can be divided into the following general ...