Victorian Ring Sterling Silver Filigree Moonstone Antique DazzleCity

So here's the story - it belonged to my grandmother. She passed in 1978. I never had any details. I'm headed to the end of the trail myself and need to start passing things on. It has a wonderful high crown filigree. The stone is a mystery to me. I think it might be moonstone. The size is 5 3/4.  I've never made any attempt to polish it but it is marked STERLING inside the band.  It's a delicate piece - excellent craftsmanship you don't see these days.