I hope these pictures are of a quality you can determine whether or not this coin is improperly annealed. Probably wishful thinking.
Make sure it's glossy black in color, just like the 1959 black beauty . I just found another 2016-D rosy and it's glossy black in color .
My son found it in change not sure if it was from store or bank roll? Sorry I know it's not much help. It's not rust or corrosion just a black quarter, I've been through a ton of coins of almost every denomination and this is the first I've seen than black beauty nickels in pictures.
