This is an old piece of Czech glass from the 1940s. It is a classic emerald cut that looks like carnelian. The clasp provides a low-cost alternative to the actual stone. The color is close enough that you could use it with carnelian and no one would ever know. The centerpiece is 10 mm by 12 mm and is set in a sterling silver box clasp. The clasp is 26 mm from ring to ring.