Possibly. With zinc again? I'm pretty knowledgeable about my metals I'm a welder by trade that's allied work with. That's zinc notice the blue grayish tint from being exposed to oxygen. Its almost like the coin was struck normal because outside of rim show copper. Make me wonder if plated or dipped in something why copper around rim should be first to go. That's why I posted this there's slight traces of copper like it just faded away.