Sterling Silver Textured Ring with Deep Dark Green Stone Size 8

VIntage sterling silver ring with a crosshatch textured design. It is bezel set with a dark green stone that tests as Emerald. Stone is very clean and may be a synthetic emerald, a green quartz or a stone that I have never heard of. It looks like chromium diopside, but that tests as glass. This is a gemstone. It is 7mm in diameter. Ring is a size 8. Weight: 5.3. Hallmarked inside.