Re: cleaning river find's?
I don't know what the metal composition is of this type of thing but if it's bronze then the green might be a problem.
There's such a thing as ?bronze disease.??
Does the green rub off as a sort of powdery light green dust? If it does, it?s most likely bronze disease.
If you suspect? bronze disease, check with ancient coin collectors, they can tell you how to get rid of it.
Bronze disease left unattended can destroy many old relics.