Found this what do you think?Has o's all over the coin. I cant seem to use my computer will try to upload better photos.
It’s blisters in the copper plating. Environmental damage. The copper plating is broken exposing the zinc core. The zinc reacts with elements and corrodes. Hydrozincite.
http://www.error-ref.com/?s=plating+blisters This is a great site to look up the different kinds of errors.