You need a better picture than that. Can't tell what that is.. Probably a huge cut that raised the copper. IMHO
One thing I can help you with: Your poll doesn't make any sense. Don't click on the "Poll" section when you don't need it because there is no backing out until you've completed it. A poll is used for the members to vote on a particular subject.
Whatever it is that coin was in a very strong acid, obscuring and likely deforming it, as well. I mean, look how it left it. That was no red wine vinegar that did that. That coin was smoking when it came out.
Yeah it’s pretty crazy looking I thought it may be grease or possibly intense heat but acid sounds possible Thanks for the info