not sure why you decided to do anything to the coin but that should never ever happen. As stated above I am not sure how it effects the coin as I have never heard of this treatment but I can tell you that I wish you would have asked in here before doing anything to the coin because it needed nothing. The only reason to ever do anything to a coin is if there are verdigris that can harm the coin if left on there, but this one had no problems at all and can decrease the value by a HUGE amount and in some cases make a valuable find worth nothing but face value. I don't know where you read that this was acceptable but I sure hope it wasn't a coin site, because a coin should never be cleaned unless there is no other way to save it from future damage. The chances of it ever lightning up is never going to happen, no matter how long you wait. Your son could be 130 and it would still be dark if not darker from the treatment you applied to the coin