I know this1985 d Lincoln cent is zinc. And from what I've learned from you people zinc sucks. I can see why but this cent has , which appears to be metal to me is right on the mint mark also between the eight and the five on the date. I know zinc is notorious for bubbles lines peeling and whatever else zinc does. I'm trying to understand the mint mark has had punched I believe they didn't stop that until 1990. Is it possible the d broke and a piece lodged in the coin and the dot between the eight and the five is a die chip. As always thanks again Merry Christmas
Looks like a plating blister. Either that or a die chip. You could poke it with a wood toothpick. If it is a blister, it will pop. I wouldn't do that if you think you want to keep it as is.
They are plating blisters from the copper coating. If you poke them they will more than likely burst and then it starts to rot.
