What would the experienced members advise? I've a hammered medieval silver coin with an unsightly (to me), patchy black tarnish, I don't think the surface of the coin under it is damaged. Can and should I remove this tarnish, which I believe would definitely make the coin look more attractive or not? If the answer is 'remove it', what would be the best way? Thanks in advance for any knowledgeable opinions. John.
Agreed. But, it should be noted that how to do it is the easy part. The hard part is determining if it should even be attempted as well as which method to use.
The general rule is don't clean coins because it's so easy to destroy their numismatic value. If the coin is valuable have it conserved professionally. If the coin isn't valuable leave it be.
The answer to your question will vary greatly based on what kind of coin it is, what metal, what type of corrosion, how bad it is, how widespread it is, how tightly adhered it is, what type of damage may result underneath, and the value of the coin. Please post clear pictures, because you won't get any meaningful answers without more data.
With ancient silver coins, lemon juice is often used. With more modern coins eZest is a dip that can be used usually with uncirculated and proof coins. With more worn coins, eZest should be used with extreme care if at all. Let's see the coin.
It is just normal surface grime. Don't remove it. It actually makes the lettering stand out. Removing it will decrease the value of the coin.
Agree with @TheFinn it looks fine as is. I think there's a high probability of making it look worse if you mess with it
