There is a website called CoinQuest.com US Morman gold piece 1849 to 1860. All the ones that Mike Locke has seen are replicas.
I cannot speak to authenticity, but the coin is of the design of a mormon gold coin. They are listed in the RedBook, and the gold content is squirrelly with these. Authenticate it with someone knowledgeable who can look at it in-hand, then you'll know better what you have.
@JCain How about a little more information from you. Did you find it? How? Metal detecting? Flea Market? Have you tested for gold content? It looks fake to me. If you open up the website provided to you in an earlier post it will explain why yours could be a copy of the original.