These cameos are lovely! The carving is exquisite, the colors of the natural shell are perfect, and the mountings are simple and subtle, yet rich, with an easy-to-match, latticework filigree.
Cameo is the art of carving a layered material, creating a portrait or landscape with the difference in colors. While traditionally done in shell, banded onyx has been used in cameo work - particularly in Greece and Italy - for hundreds, if not thousands, of years.

Metal: 18 Karat Yellow Gold
Cameo: Natural Shell, likely conch. Measures 14 x 10 mm oval?
Earrings Length: 20 mm
Earrings Width: 15 mm
Time Period: 1950's