A rare Ostby & Barton sterling silver filigree enamel, green glass oval ring pin with swivel filigree that converts it into a pendant. Measures 1 1/2" across by just over 5/8" high. When you open the filigree bale it measures 1 7/8" long. The ornate filigree pendant bail snaps in place onto the pin. It is in excellent condition overall. On close inspection with magnification there is an old touch up to one of the black enamel accents. Marked on the back OB Sterling.