What is the marking on the inside? If 925 modern. If makers mark, could be made of "coin silver" which is usually 800. Coloration looks similar to other coin silver items I have found in Europe. This could place it in 1800's. But corrosion is dependent on soil conditions. One field will have shiny silver. Next is dark and corroded becasue of fertilizers.
That said design looks more modern. It appears to be a cast ring (lost wax process). The mark on the inside would be best chance of dating it. With info shown could be anywhere from 1880 to 1960 in my non professional opinion.