Something Really Strange Going On With This (1974) Kennedy Fifty Cent Piece

agree with Coop.

Hello Everyone;
I hope you are having a great Fourth of July.
I'm here just looking at this soaking wet Kennedy half dollar that has been
soaking in acetone for over 24 hours and there is no change in the color.
I also have a new observation and want to show.Having looked at it, their seems to be that same brown ,gray matter around the edges of the coin.
I don't know if it is anything its really puzzling.
I just look at it and think it was a substance chemical reaction from the tape but the tape isn't on the edges or is it?

At this point we don't really know and no body in this community seems to know for sure so far, what really caused this and if you aren't curious I don't know what to say .But I can say I might have the only one in the world even if it may or my not be a error ,at least I tried to find out.
Thanks for listening

Thank You Nfine;
That sounds really good only if their were other coins to compare it to.
The stripe is really amazing its right down the middle which I think looks really cool, it would make sense to hold down the coin there.
Im thinking if they were making coins wouldn't they need to mark each
sheet of metal maybe this was tape on the metal to help identify each kind of metal sheets that's why it doesn't fade in the acetone .The pressure and heat from the press could maybe cause this?
Just a guess

Thank You CuJohn;