Hello, I came across this 1998-D 1C. Is this what is known as "zinc rot," or is this some other kind of damage or a mint error? Thanks.
zinc rot is what's happening to the exposed zinc, it's actually zinc oxide to protect the exposed zinc. the diagnosis is zinc rot overall, but someone scraping away the copper on the coin is the cause of the zinc being exposed, either by kicking it down the cement for a while or rubbing it with sandpaper, or it spending time in the street, or whatever. the copper plating was abraded off of the coin and exposed the zinc core. Paddyman98's picture of of zinc rot appear to be caused by "bubbles" in the plating that ruptured then the zinc oxide that forms getting knocked off over and over again, either from being in the ground or in a fountain, something like that where the zinc stays exposed and the oxide can't remain on the exposed zinc and the oxide never really being able to stay put to protect the exposed zinc, so more and more gets sacrificed eating away the zinc. I have one on 30 years old cent I've protected with flips and left alone and dry that had split plating and lots of exposed zinc on around the devices and besides the light white layer of zinc oxide over these breaks in the plating, no further "rot" has occurred they look as good as new, with split plating still. Why did I save it? I have no idea maybe the very faint L in Liberty? maybe what appears to be a die crack or something at K6 of the reverse? Maybe the oddly flat areas on lincoln all over him, it caught my eye 30 years ago and I've hung on to it a lot seems to have gone wrong with this one. Here it is in all it's majesty. LOL! The point being though, if nothing knocks off the zinc oxide, it can rot REALLLLLY slowly. It's probably the most extreme example of split plate I've ever seen that didn't involve a broadstrike.
