Bvan

Hi there I am new to the forum and hope this is the right place for this post. I recently brought this coin but I am struggling to identify exactly what it is. It seems to be some sort of a coronation medal or coin from 1821. It is 40mm in diameter and weighs around 26g but it does have a hole cut into it. I have tested it with a rare earth magnet and it doesn't appear to be silver. It says July 19 1821 on it. I have searched google and can't seem to find a similar coin or medal anywhere. Any suggestions as to what it is would be greatly appreciated. Thanks in advance.