What can cause something like that to happen? I am thinking it was during the minting process... But then I don't know S*^t from Shine-o-la, so what do you guys think?
I was thinking that too Mountain Man until I put it under the microscope then I could see that it was elevated.
If the substrate zinc had a weird anomaly that was plated and coined, it might have eventually succumbed to conditions and rotted from the inside...out.