Cleaning an old coin can reduce its collector interest and remove information from the surface. Polishing, abrasive products and chemical treatments can leave marks that are more damaging than the original dirt or tarnish.
Handle the coin carefully
Wash and dry your hands, hold the coin by its edges and work over a clean, soft surface. Photograph both sides and the edge before moving it. Do not scrape, polish or apply household chemicals.
Store coins carefully
- Use inert holders or envelopes designed for coins.
- Avoid PVC soft plastic that can damage surfaces over time.
- Keep coins away from damp, heat and direct sunlight.
- Store different metals separately where practical.
- Record the date, source and any known history.
When to get specialist help
Ancient, precious-metal, historically important or unusual coins may need specialist handling. Ask a qualified conservator or numismatist before cleaning. Research the safe coin-value method and errors versus damage guide first.