This is a 1915 Austrian one ducat coin that features Emperor Franz Joseph I. The reverse shows an eagle with the arms of Austria. I picked this coin up at a jewelry shop quite a long time ago. It measures 20 mm in diameter and is only 0.8 mm thick. It weights only 0.1106 ounces is interestingly 23.75 carat gold. Many of these were re-struck after 1915 as bullion coins, of which this is very likely one.
They were produced in one ducat and four ducat varieties and are extremely thin. I had purchased this coin when gold was very low and only paid spot at the time so definitely a good deal.
This coin I did end up selling when gold was high as I was starting up a new business, and these are scans I still have in the old laptop. I was never really attached to it, but it is an interesting coin with an interesting history. Definitely worth adding to your stack if you come across one at spot!
