We need to at least know what metal it's made of as copper reacts differently than silver , pics are best though .
sorry had to work, have to make money to search money...here is a pic of the crap, Tar? Glue??I just don't like not being able to see the entire coin..
Preferaly the xylene first (it takes forever to evaporate). It almost looks like a plastic in the first one so xylene might work best. Then again, could be glue. It's too bad you can't buy diethyl ether at a store >.>