So is this correct---this coin moved into the die with another 1/2 coin still in it? then was struck..so would this be a die cap? or brockage? Never ran across one..
Very interesting. Not something I would have guessed as I had never heard of it - LOL. Always something new to learn with error coins. BTW nice find!
They're not particularly rare. They are much more common than conventional in-collar uniface strikes (two normal planchets struck within the same collar).
It does have a finned rim as well. This is a side-effect of the increased effective striking pressure generated by the abnormally great aggregate thickness of the two planchets.
Struck through split planchet I agree with Mike's diagnosis. I like this error type personally. In case you're wondering, I would say the coin is worth $40-$70. Jon