Hello everyone, my friend found this coin in his change. The pics are terrible, sorry. The nickel has a normal color on front but at the rim it turns a copper color which continues to the back. Could this be some sort of chemical reaction? I don't believe that these coins are clad in layers, please correct me if I am wrong. So I really just want to see what the experts think. Thank you all in advance.
I've had nickels turn that color after exposure to a weak acid -- it can leach some of the nickel out of the copper/nickel alloy. That alloy that's left is high enough in copper to turn this color.
