Sometimes planchets for one coin denomination are fed into a coin-stamping press equipped with dies of another denomination. This results in a coin that has been stamped with a design intended for a ...

Minting coins isn't exactly an exact science. Even though most coins are perfect and uniform, small mistakes can result in error coins that are super valuable and ...

Some of the rarest and most valuable coins in U.S. history owe their worth to minting errors that slipped through unnoticed. Coins like the 1943 Copper Penny, struck in copper instead of wartime steel ...