Looks extremely rough what ever it is, and if you see detail which resembles a Sommer Islands coin just as a starting point you would have to see it clear enough to establish the variety. Probably something tough to do on a coin that's so poor, and even if it looked close to a genuine one, I doubt you'd ever get a professional confirmation.
PS: I have one that has clear detail and also looks just like a very old coin, but it's fake!