Nickels are not plated. Could be heat damage. It was in an ashtray and someone turned thier cigarette off on it. FYI - Business strike Quarters, Dimes have a Clad layer with a Copper core Cents minted after mid 1982 are Copper Plated Zinc Core Planchets Nickels are not Clad or Plated and do not have a copper or zinc core. Understand?
There’s no such thing as plating blisters on a nickel. That term is only used to describe cents minted after 1982 (copper plated zinc core).
Edited : Fixed the quotes Gotcha, the reason I said "blister" is due to the streak on the right side of the coin, the last two column, the streak looks raised like bubbling and looked similar to what you see on a zinc coin. This is good to know though..thanks! So they mix the metal (75% copper and 25% nickel) to make the coin? Thanks again!