The one side of that coin looks VERY similiar to a coin I dug here in PA. back in June.
But the other side is definately not the same.
But I think it's a safe assumption to say that it's German. (Or something close to German.)
The coin I found is exactly the size of a Quarter.
Here's a link to a picture of the Coin I found, when I posted it back in June.
Hope it helps a little.