This is a 1990 coin. There is multiple areas around the lettering and building on the back that looks like blobs of melted plating. There's also something between the 1 & 9 that I initially thought was a misplaced D mint mark but now I'm wondering if it is just a die chip. Appreciate any input.
this looks like it starting to rot. since 1983 our cent coins are just zinc with a thin copper plating on the zinc core. when the zinc rots it swells up.