This coin ring is made from a large Chinese coin, it was sold to me as a Tibetan silver Chinese coin which basically means nothing, as there is very little if any silver at all in the metal which seems to be some kind of copper alloy.
I believe that the coin is a copy of a large silver Chinese Dollar.
Having said all the above the ring has a rough and ready charm. The ring is very large and chunky.
The ring can be sized from UKW up to Z +6 and bigger if necessary.