“Is my coin an error?” Common false alarms
Damage, wear, chemistry and plating – why most “errors” are not errors and how to tell for yourself
BulgarianCoins editorial team 3 min read
Every week someone finds an “error coin” in their change and lists it online for hundreds of euros. It is almost always damage done after striking. Here are the most common false alarms and how to recognise them.
The basic rule
A minting error arises at the mint. The metal is pressed by the die. Damage happens afterwards – in a pocket, in the ground, in fire, in a chemical. So:
- With an error, the metal is displaced, but not missing.
- With damage, the metal is often worn away, cut or melted.
The common false alarms
“The coin is a different colour”
The cause is usually chemical – oxidation, contact with acid, fire, a cleaning product. Copper coins darken or turn green. Silver coins turn black. This is not an error. See Patina or tarnish.
“The coin is thinner or lighter”
Wear, acid or filing. A genuine wrong planchet has a complete, clear design. A worn coin has rubbed-away details.
“A letter or detail is missing”
Most often – wear or a knock. Sometimes it is a filled die – a genuine but very minor error of little value.
“A double image”
It is almost always machine doubling – the die bounces slightly after the strike and leaves a flat shadow. It is common and has little value. A genuine double strike is much clearer – the whole design is visible twice.
“A dent” or “a bulge”
Knocks and pressure after striking leave dents. A genuine error – for example a cud from a cracked die – is raised and has a smooth surface.
“The coin is gold-plated”
Gold-plated circulation coins have usually been treated by private individuals, as souvenirs. They have nothing to do with the mint.
“The coin is bent”
A bent coin has almost always been bent after striking – in a machine, by a wheel, by a person.
Checklist
| Question | If the answer is “yes” |
|---|---|
| Is the design complete and clear? | possible planchet error |
| Is metal missing and the edge uneven? | probably damage |
| Are there tool marks? | damage |
| Is the colour the same over the whole coin? | if not – chemistry or plating |
| Is the weight different from the catalogue? | possible wrong planchet or damage |
| Are there many like it? | probably a variety, not an error |
What a damaged coin is worth
A damaged coin is worth less than a normal one – not more. If someone is selling damage as a “rare error”, they either do not know, or know all too well.
The genuine errors
Genuine errors exist and are valuable. But they are much rarer than false alarms. See Error coins, Mules and wrong-planchet coins and Die varieties.
If you are still in doubt
- Compare the coin with the photos in the catalogue.
- Weigh and measure it.
- Examine it with a loupe.
- Show it to an experienced collector.
- If it is valuable, consider grading.
And above all – do not clean it. See Should you clean coins.
