Congratulations to several correct guesses.You all are just too good. It is indeed a Mint Medal.
The story is thus. Years ago my parents dropped me off at the old San Francisco Mint and then they went to Fisherman's Wharf. Back then, and this was just after the dinosaurs died out, one could go to the gift shop and purchase the blanks for the mint medals, for $1.50. You then walked a short space down the hall and could watch the medal struck as you pushed the button handed to you by the operator. Well, being a collector of a few error coins I purchased two blanks and had only one struck. The blank must be scarce I would imagine.
Side note. The mint closed 15 minutes after I was left there so I walked all the way to the wharf to find my parents and family. A long walk it was.
I have only a Golden Dollar Planchet, a Suzie and a couple of cent planchets. I have sold many different blank planchets over the Years.
