I think your first reaction was the accurate one, somebody mounted it as jewelry or for some other reason. You can verify if metal was added, it should weigh 3.1 grams on its own.
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I have a 1957 D Wheat Penny that just isn't right. There's a huge collar around it, as if excess copper wasn't stamped fully out of it. Not sure how the minting process works, but it almost appears to be two blanks stamped at the same time, as there is a noticeable seem or crevasse through the collar. At first, I thought it might be something that was added on after the minting process, as it looks too uniform to be a mistake, but upon closer inspection, the bottom left quadrant of the
M
Marc's Expert Appraisal
ANA-Certified Numismatist · Hudson Valley Numismatics
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1864 Indian head penny. Was curious if it's worth anything? Thank you
A dollar or two, it's very corroded; with skilled conservation, maybe $5-10.
1942 Australia penny
What fun! Give it to a kid to get 'em off the cell phone. I'd charge a dollar!
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Just face.