Vesuvian cameos were often souvenirs from southern Italy in the late 19th century. Cameos carved on lava were usually creted in the Naples region of Italy. Lava cameos have a matte surface and can be many different colors.
The Vesuvian Cameo Earrings are bezel set in 18K gold with my dotted detail on the side, measuring about 3/4" from top to bottom. The bottom of the post  earring has a cultured pearl attached.