Paid $25 for this only because it fit me and I had never seen anything like it. The markings on the back are Caracol and then an Eagle head with 925 (very small) under it and then some weird undecipherable symbol possibly a makers mark. I assume it's Mexican and some designer however I can't find the symbol online anywhere. Sorry I can't a better picture of it, it wasn't on any silver encyclopedia pages. I have never seen a ring like it before, funky looking. Any idea on the age? Definitely older because of the patina on it, 1970s? 60s? Onyx stone as well. Any input would be great!