Antique arts and crafts, medieval revival, Byzantine Revival white enamel, faux newest topaz after Rikers and sons stickpin

Arts and Crafts movement stickpin, after the designs of Riker and sons of New York, white enamel with lines and circles with a floating faux topaz cabochon in the middle. newest It is designed after the Byzantine revival movement of the arts and crafts. It measures 2 1/2 inches long. Thanks for looking!