Blue stone sterling ring

Blue stone or gem sterling ring. Any thoughts on this ring ? I don't think I ever seen a sterling ring made like this ( adjustable ).

 

They used to make a few back in the 60s, often with glass stones, sometimes with real ones.

 

I see many adjustable rings especially in Sterling, often for growing children and it's safer because they are easily removed. As for the stone, it looks like glass from the picture.

 

Evelyb30, 1960's right , hopefully stone.

 

Houseful, Thank You.