Vintage Sterling Green Stone Ring

Here is a beautiful and quite old sterling silver filigree ring with a unique green stone, I’m not sure what it is, but it looks like it could be some type of Azurite or crushed stone and/or glass. Does anyone know?
The setting is an ornate filigree design with large prongs to hold the teardrop stone. It has a split shank adjustable band. I was surprised by how how comfortable it is and that the size rage is from 6.5-8.5, give or take. Stamped Sterling on the outside of the band, which is common in East European jewelry. One of a kind!
Will arrive boxed or in a jewelry pouch.

I’ve been collecting modern and vintage jewelry for years. I need to downsize, so I am passing on some of my beloved pieces down to others. Many items were passed down from family members. Others were purchased from estate sales, galleries, artist co-ops, thrift stores and while traveling. If you’re looking for anything specific, let me know! I might have something you’re looking for!