I don't know if this specimen is worth very much, but it's a definite curiosity. It might be a mule. The one I'm asking about is on the left; the other is a normal 2010 penny. To my eyes, the one on the left has a rim that's noticeably thicker than the one of the right. Did it come from a proof set? Is it a mule? Or have my eyes gotten whacked out from too much roll-searching ? Thanks for your help.
