Memorial Coin

What kind of error coin is this?

It is a Jefferson nickel struck on a 3.1 gram copper planchet. I believe it was struck as a penny first because the coin has all of the motto’s and the bust on the obverse and the memorial on the reverse but then it seems as if it went through nickel dies?? What is it called?

It is a double denomination error. The coin would often be called a 6 cent piece. A 3.11 gram copper planchet is 95% copper and was used almost continuously from 1857 until mid 1982. The links give more information. I hope that helped.

Word Trade Center Memorial Coin