They can turn many shades... but there is a difference between a "toned" coin, or a discolored coin, and a Black Beauty. Many factors play into...
Sure they can turn different colors.. But then they're not black nickels, they're discolored.Black nickels are the very hot or overheated...
I have a 1958, that looks like it had copper corrosion... blue green residue. So, like you said I weighed it. It weighs out at 4.77 grams......
Weigh the coin... be sure. Copper will bleed through on occasion, and it will tarnish through, blye/green usually. Weigh it!
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