I found a copper nickel, 1977, cant see a mint mark. I have no idea where to go to get info aboutit.?
I never seen or heard of a copper nickel sound more like some kind of tarnish.
US nickels are 75% copper and 25% nickel. If left sitting in water - especially outdoors - they will turn a brownish color. No mint mark for that year means it was struck at Philadelphia. Once in a while, a problem during production will result in a sheet of metal discoloring. They are usually caught, but one can get into the stamping machine that produces the coin blanks, and a few discolored coins have gotten out. They may be the color of a circulated penny (never the bright shiny color of a new one) or even very dark, and they have some value. But to know if you have one of these, or just a coin with environmental damage and no value over 5 cents, will take an expert looking at it.
