Hi everyone. New member here. I've been collecting for a while, and my parents gave me some of their old coins. I came across this and was wondering if anyone knew what it was. It says "United States Federal System" but there are flags of China and the U.S. on the back. It also says "gold certificate" and "1,000 lines. It's dated 1913. If anyone can shed some light on it, I'd greatly appreciate it. It's larger than a silver dollar (diameter wise) and looks like it's made of either copper or bronze. Thanks!