Jefferson Nickels With ?annealing Errors? Or Damage?

Enviormental damage on the first one. They look like that they are found outdoors.

The rest look circulation damaged.

I agree. Each is an example of environmental damage and or staining. It can be hard to detect an improperly annealed coin (also known as sintered). This is one reason why I have not been to aggressive in finding the right one for my collection. I have not seen many in hand, but I would assume a lot of the determination would be in the color of the coin and its luster. I've seen improperly annealed coins that are black to bright red, so there is a wide variation in color of this one error alone. Luster would help to eliminate environmental damage and staining as being a possibility when attributing these errors.

I also wouldn't know how to distinguish a genuine example from one that was heated/treated outside of the mint after it was produced. This would be more of a concern for me with an example such as a black beauty nickel. I'm sure there are ways to tell, but I'll leave that for the experts.

very cool...thanks for sharing. I agonized over some of them for quite sometime and just decided to post them all so I could "move on".. you know what I mean? :)