One of the most important skills in error coin collecting is distinguishing genuine mint errors from coins that were damaged after they left the mint. Many coins that look "wrong" are actually damaged — and paying error prices for damaged coins is an expensive mistake. This guide teaches you the key differences.
Mint errors are manufacturing defects that occurred during the coin production process at the mint. Post-mint damage (PMD) is any alteration that happened after the coin left the mint — from circulation wear to intentional alteration. The distinction is critical because mint errors carry premiums while damage reduces value.
Accurate error vs. damage determination directly affects the coin's value. A genuine mint error can be worth many times face value, while the same coin identified as post-mint damage may be worth only face value or less.
Upload a photo of your coin and let ErrorHunt's AI scanner check for mint errors in seconds.
Scan Your Coin NowGenuine clips show the Blakesley effect (weak rim opposite the clip), metal flow distortion near the clip, and a smooth edge. Cut or filed coins lack these features and show tool marks.
Coins damaged in a clothes dryer become flattened, expanded, and scratched. They can superficially resemble broadstrikes but show uneven expansion, scratch marks, and rim damage that genuine broadstrikes lack.
Post-mint damage generally reduces a coin's value. However, certain types of intentional alterations (like Hobo nickels) have their own collector following, though these are not mint errors.
When in doubt, get a professional opinion. Professional grading services will determine if a coin has a genuine mint error or post-mint damage. You can also scan with ErrorHunt for AI-assisted analysis.