Are you saying it's fake? My mom has had it 15 years, she found it in a purse she purchased from a used clothing store. It's in rough shape but definitely looks real
It must have some value because the person before paid to have it put in 14k necklace setup. I could not find any pictures like it on the Internet, so who knows
It appears to be an ancient silver coin. Perhaps you should ask a moderator to move it to the ancient forum.