Three broad error families
- Planchet errors: problems with the blank, such as a clip or wrong planchet.
- Die errors and varieties: features tied to the dies, including some doubled dies, breaks, and cuds.
- Striking errors: problems as the dies strike the blank, such as off-center, multiple, or broad strikes.
The U.S. Mint notes that most errors are caught and recycled, while some escape into circulation.
Common damage that looks exciting
Flattened rims, tool marks, glue, heat, corrosion, plating, vise jobs, dryer coins, and impacts can imitate errors. Damage often pushes or removes metal irregularly and may cut across the design without matching the minting process.
Explain the mechanism.A credible attribution should describe how the blank, die, or strike created every unusual feature. “It looks different” is not enough.
Document it before asking
- Photograph both sides, the edge, and the unusual area.
- Record weight and diameter with non-damaging tools.
- Compare with a normal example of the same date and mint.
- Search for documented errors, not marketplace titles.
- Seek a specialist opinion before paying authentication fees.
Do not cut, bend, scrape, or clean the coin to “test” it. Those actions can destroy the evidence needed for attribution.
Sources and examples
- U.S. Mint: Get Started Collecting Coins
- Off-Center Strike Guide
- Clipped Planchet Guide
- Doubled Die Guide