I bought this online from a person who had no idea of what he had. I have looked at it carefully, and I think it is something that happened at the mint, but exactly what I cannot say. It may have been something like grease clogging the dies, or? canadian cents should weigh 5.67 grams, and this cent weighs 5.3 grams. The edges are fine, and all beads and dentils are present and strong. Please check the pictures and let me know what you think.
Thanks for your help so far. If you check the pictures, you'll see that the centers of the coin are somewhat raised, especially the obverse. And, I doubt you could manage an acid strong enough to literally melt the copper carefully enough to keep it so nicely away from the edges of the coin without leaving an edge mark of its own. Same with a blowtorch. A capped die had not occurred to me......maybe this is a lead. To me it actually looked as though something, maybe cloth(?) had clogged the dies. But thanks for all your help. Bill.