Zincoln's have many factors that makes one believe there is something different about them, but the fact is: they are just lousy plated zinc coins. The one you have posted has plating bubbles and appears to have been in contact with something to "stain" or change the surface. NAV, but interesting to study, as are all of them.
The why I said the other! What copper plating is still present doesn't have any color change due to the transfer of high heat, no blueish, purplish, etc... color. Not having the coin in hand the shown cray looking color I thought (??) could be just the exposed Zinc core. It reminds me of say what I cheap gold plated ring looked like when the thin plating wears through and exposes the core metal.
It sure looks unique. I'll hang in to it and put it in my other collection as different but probably not a error. Thanks
