Here's a link to a previous thread on a suspected 1970-D Black Beauty nickel that was posted last year.
https://goccf.com/t/178047
I have an ANACS MS64 1959 Black Beauty in my personal collection and yours has very similar features. Because of the fact that it was removed from a sealed mint set and that it clearly exhibitis undeniable original mint luster, in my humble opinion, it looks legit to me. But the only true way to know if it was struck on an improperly annealed planchet (that I'm aware of), is through spectral analysis of the coins outer layer to determine its exact metallurgical composition.
It's an interesting coin, nonetheless!
https://goccf.com/t/178047
I have an ANACS MS64 1959 Black Beauty in my personal collection and yours has very similar features. Because of the fact that it was removed from a sealed mint set and that it clearly exhibitis undeniable original mint luster, in my humble opinion, it looks legit to me. But the only true way to know if it was struck on an improperly annealed planchet (that I'm aware of), is through spectral analysis of the coins outer layer to determine its exact metallurgical composition.
It's an interesting coin, nonetheless!





















