Forgive my ignorance. Im sure its obvious to everyone but I know nothing about coins. This coin has a red question mark on the holder so I will post images and ask you if there is anything special about this coin.
I dont have anything that could weigh it sorry. What could this be? The back has "spots" of what appear to be copper with the most of it being a very dull grey. The front is dull copper. I will try a couple more images in different light.
definitely weigh the coin and try a magnet to it. If it's magnetic, then someone is playing around with some plating.
Then it's a regular steel wheat cent from 1943; don't know what caused the discoloration, but chalk it up to post mint damage.
The copper looking stains are simply rust. The steel inside simply rusts if the zinc coating gets damaged.