"Improperly annealed" is the proper term I guess. I sincerely hope I'm not being naive here. P. S. I know some of the pics are upside down.
Interesting thread information on Black Beauty. 1959 jefferson "black-beauty", just how many are still out there? Discussion in 'US Coins Forum' started by chasindreams, Feb 1, 2010. Dave
So.. questions for you Where did you acquire your Nickel? Roll? Change? Metal detected? Have you attempted to clean it? Don't!
It looks like a good candidate but not 100% sure. Your first 2 pictures are the best. Here are mine from my collection