Possible, but I saw they were having a hard time finding airtites and the same for st gaudens and $20 double eagles would work. Edited to add- as far as I knew they made 1 5/16" and 3" medals, but I'm no expert on these.
They are probably made of bronze. I have the complete set of 1-5/16", and I believe they also make one in 3". Chris
looks like it was set in a jewelry piece. post this in the ancient coin forum... they can tell you what it is...