To Clean Or Not To Clean!

It is possilbe to correctly clean or conserve an ancient coin, many have done it but learn about it before trying. It's good to experiment on cheap ancient coins before trying it on a valuable one. There's posts here on CCF about it and Youtube videos you can watch. Do not use anything abrasive. Many soak ancient coins in solutions like distilled water, olive oil for weeks or months. Many ancient and modern coins found in the ground need to be carefully cleand besause of the encrustation. A bried soak in acetone may help.

The green areas on the reverse look hard and stable, they likely won't come off and you could make it worse trying to remove it. It's called vertigris. In that case I'd try Verdi-Care which I've used to improve the appearance. When green stuff on ancient coins is powdery it could be active bronze disease which needs to be treated to stop the corrosion.

Your coin might clean up okay...but it might look worse. It helps to know what you are doing before trying to clean a coin. You should practice on some culls to better understand what will happen. I used to clean lots of ancients; but now only clean occasionally. Here are a few that I have cleaned --