This is a lovely vintage Chinese export silver filigree and jade ring. It is set with an oval cabochon that tests as jadeite on the gemstone tester. The back of the setting is marked Silver (very blurred) indicating a grade of silver lower than Sterling - probably around 800. It originally had a gold wash over the silver but this has mostly worn away. It is adjustable.
The ring is currently about a size 5 1/2 but could be sized up or down at least a couple of sizes. The stone measures about 1/2 inch north to south. It is in good condition with a small loss to the filigree on one side. This is less evident in person than it appears in the pictures.