Vintage Sterling Silver (no marks) Genuine Shell Carved Cameo Brooch Pendent Marquisette, with the gold rope around. Signed

Vintage carved shell cameo bezel set in sterling silver ( no marks) with fabulous floral and marquisette frame with the gold rope. Outstanding quality of carving. Can be worn as a brooch or a pendant. Cameo is signed on the back, maybe Rollouo or Lollouo, but not sure. Measure 2 inches. Weights 16.92 grams. No chips, cracks, stress lines. Not sure about age of cameo