Hello, Spiros --
Your coin is a replica of a pattern trade dollar from the US. It is worth a few US dollars.
The coin in the picture is marked with COPY to indicated that it is a counterfeit. Not all fakes are marked as such. Buyer beware!
Genuine trade dollars were minted from 1873 to 1885 and were used in Asia to compete with dollar-sized coins of other countries. You can read our evaluation of genuine pieces at this CoinQuest link. We also have a second pattern replica which looks different than yours at this link.
Patterns, by the way, are coins minted as prototypes before actual production begins. Only collectors with deep pockets can specialize in these very rare, and often very beautiful, coins.