A mule is a coin with mismatching stamps on either side. On this specimen, one side was stamped with the 50 cent reverse and the other with the 20 cent reverse. Next, there was a French 20 cent ...

This 50 cent coin might look normal, but there's a tiny error that makes it worth up to $40. (Source: TikTok) Coin collector Michael McCauley called out the 1979 50 ...