Interesting coin. I'm not certain, but I'm leaning towards a defective planchets and plating defect. It looks like the recessed area by the date was weakly struck, not damaged, and the exposed zinc was never plated, not removed post plating. Also, the rough plating edges around the date and field don't appear to be from zinc rot. I wouldn't be upset if I was wrong and it turns out to be PMD, but I'll go with defective planchet for now
On first looking at this coin, damage comes to mind. But when you take a closer look I believe it was a defect of some sort on the planted before it was struck. If you look at the date everything that’s going on in the coin is under the one in the date. If you look at the larger area, again that appears to be damaged. You can see what appears to be scrape marks on the left side pushing all the metal lower and to the right. Giving another closer look, the Y in LIBERTY it’s on top of the damage. Therefore, in my opinion, I believe the planchet was damaged before the coin was struck. I may be wrong as I’m only looking at photos but that’s what I see.
Part of it looks like heat damage. The blue stuff may be toning of exposed zinc? Still a good question. Maybe a combination of a struck through part of another coin and part damage?
The first is the date edge and the second is the opposite. There is no damage on the edge or reverse.
What He said. LOL. Very interesting. Newer Pictures are better though. Looks some kind of defective planchet as some of the others have pointed out.
My money's on epoxy with all kinds of good things in it . I think if you clean it with acetone everything will come off .