What is a five center piece in Huckleberry Finn?

This post is really old but I did a little research and found that in 1884 (the year Huckleberry Finn was published) and 1885 there was a coin called the ring nickel that had a face value of 5 cents. I'm not totally sure if this is correct but I couldn't find anything that gave me a definite answer. Hopefully this helps someone :)