Large Modernist Sterling Silver Jasper Agate Brooch Hallmarked 3″

Offered is a simple yet elegant large modernist sterling silver brooch.  The domed frame of the pin measures 3″ x 2 1/4″.  The stone is bezel set and is 1 5/8″ x 1 1/8″. This portion partially extends over an open area and is braced from the back side.  It has a yet unidentified maker’s hallmark and is marked sterling as shown.  The vintage jewelry piece has no condition issues. Total weight with stone:  33.6 grams