Congrats on your find.
Hard to tell from your picture.
Is there and makers marks on the back?
A size reference would be good in helping also.
Unfortunatly by the looks in your picture, it has the look of costume jewelry and in it's condition not much if any value.
Clean it up, check for any markings, post pics front and back and have it checked by a jeweler.
Keep up the hunt and good luck