MintPricedShould you clean coins? Usually not
The most common mistake new collectors make is cleaning coins. It feels like it should help, but for collectible coins it almost always lowers the value, sometimes dramatically.
Why cleaning hurts
A coin’s original surface — its luster and natural toning — is part of what collectors pay for. Polishing, rubbing, chemical dips and abrasive cleaners leave fine hairline scratches or strip away the surface, and that cannot be undone. Older coins with deep, even age coloration are more desirable than coins whose surfaces have been stripped. Many grading services describe cleaned coins with a “details” grade instead of a numeric one.
What counts as cleaning
- Rubbing with a cloth, eraser or toothbrush.
- Metal polish, baking soda, vinegar, ketchup or lemon juice.
- Silver dips and electrolysis kits.
- Ultrasonic or tumbler cleaning.
What you can safely do
- Leave it as it is — for anything that might be valuable, this is the right answer.
- Loose dirt on common coins: the U.S. Mint suggests that if you do wash a coin, use mild soap and water and pat it dry with a soft towel — never brush or rub.
- Valuable or problem coins: professional conservation services exist; ask a grading service or a reputable dealer before doing anything yourself.
Prevent the need to clean
Most damage happens through handling and storage: fingerprints, moisture and PVC holders. Hold coins by the edge over a soft surface and keep them in suitable holders. See how to store a coin collection for the details.
Buying tip
An unnaturally bright old coin, or one with a uniform pattern of fine parallel lines, has often been cleaned. Compare with photos of graded examples before buying. See condition and grading basics.
Sources and further reading
Related question in the coin FAQ: Should I clean my old coins?
General information, not financial or appraisal advice. Values depend on condition and the buyer; ask a qualified dealer or grading service before buying or selling.