I do not know much about this piece so please use pictures and your own judgment. I can answer any questions you may have to best of my ability. I do not know what the center cameo is made of. It is blue and sounds like shell or glass when I tap on it. There is an engraved patent number on the back of 1852188. The clip still work. The piece is approx 1 7/8” long. Smoke free home. Shipped to you with USPS GROUND ADVANTAGE. Thanks for looking!