How to Restore Polished Surface of Old Coin

Evaluate whether your coin should be restored. If you have a coin that you think might hold some value, it is typically best not to restore it at all. Collectors value the patina coins acquire with age. However, if it's a coin with sentimental value that you just want to polish until it shines, then it may be worth restoring its surface.

Using your cotton swabs, rub the surface of the coin with olive oil. You want to coat the coin's surface with oil, but you also want to be sure not to cause any further abrasions. Don't rub as if you are scraping the surface clean, but instead as if you are applying a coat of paint.

Dab dirty spots with a cotton swab. Once again, rub gently.

Rinse with distilled water. Do not to touch the face of the coin with your fingers after rinsing, as it could impart the oils from your fingers on to the surface.

If dirt remains, repeat cleaning process with petroleum jelly. Petroleum jelly will adhere better to particles of dirt on the coin's surface and should lift away whatever grime the olive oil left behind.