I got this in my register a little while ago, and it has me wondering what happened to it. Any ideas? It looks most likely like pmd, but im not sure how it could've happened. It's missing a portion of the clad layer, but in the shape of a clipped planchet area. Both sides are that area have a kind of 'clipped' look. Also the letters within that area seem fine. Here are the best pictures I could get. Hope they help. Any thoughts are appreciated.
Maybe a lamination where the piece fell off? it looks like there is almost an indentation in the coin. I would say either lamination or someone spilled some acid on it
Looks like part of the cladding is missing. Looks like it was there when the coin was struck. The copper colored devices are ghost like. (after the cladding came off , they look that way. If they were strong, then it would have been struck without the cladding.)
Ill try to get some better pictures. All I have is my phone, I'll try and borrow a camera. Thanks for all the input, its very interesting looking either way. Id love to know what it is though, so ill work on good pictures.