to this wonderful coin I would like to remove the earth in the joints without ruining the patinaa and without causing micro scratches. In order not to affect the value and the grade of the coin in question, can I pass it with cotton swab immersed in demineralized water? Do you also know what mint it is? thank you again for the super support.
I wouldn't do that, it could lead to scratches (so I've heard). Try the lemon juice first. I usually start with part lemon juice and water. If needed, I will increase the concentration of lemon juice for stubborn deposits. I've also had great results with vinegar as well.