Hi! I'm a jewelry collector, and I don't know anything about coins.

Hi! I'm a jewelry collector, and I don't know anything about coins, although I love the history and art of metalsmithing. Is this coin a fake? Its very thin and smaller than a dime. Someone on this sub helped me identify it as " Follis Thessalonica - 330 A.D. ". I've looked at other versions of that description, and nothing really looks like this one. Thoughts?