It's environmental damage after it left the mint. so it's not an error. Copper is a very reactive metal. There could be countless things that would cause a cent to tone. In other words, your guess is as good as mine or anyone else on here.
Hello Kitty! I certainly believe Oldhoopster is correct, but I am just curious about the reverse of the coin....The " B" in " PLURIBUS " looks more like an " 8" than it does a B.....There is I would believe a very good chance that that B was damaged after leaving the mint ( Post Mint Damage ) But I would look into it if I was you....It doesn't hurt. Good Luck !!
Ketchup. Believe it or not, people "clean" them up like that in ketchup. When you see them pink, like that, think ketchup.
