Reale Coin From Which Wreck?

Welcome to CCF! Difficult to say without the sales receipt when it was bought which should have been kept for provenance. I know Mel Fischer's company sells jewelry like that from shipwreck coins like the Atocha. You could contact them to see if they keep sales/photos records of what they have sold through the years. Other jewelers/companies may have have made similar pieces. Mel Fischer is the only one I know about.

@sol, your post has sat for a while in our unidentified subforum and while you've got a couple answers, it seems to me that this thread belongs in our world coin subforum. There are a couple people who hang out there and might have additional thoughts as to the origin of your Reale.