Superb Victorian era pinchbeck cameo brooch/pendant

Measuring 1-3/4 inches tall, this piece has the design, closure and materials of the late 19th century. The detailed Grecian portrait has an open scalloped frame adorned by an orb on top and another on bottom. There is a simple but secure "C" clasp (and the piece can be worn as a pendant by hanging it from the frame's top opening). The cameo is genuine shell, and my research suggest the frame is pinchbeck, a form of brass mixing copper and zinc in proportions to resemble gold. I can find no markings. The piece is in excellent vintage condition.