Known as crotalia (from the Greek word for rattle or castanets) because the pearl pendants would produce a jingling noise when worn, earrings of this type were extremely popular with Roman ladies. Numerous examples have been found at Pompeii and Herculaneum.
Richter, Gisela M. A. 1924. "Greek and Roman Jewelry: Recent Accessions." Bulletin of the Metropolitan Museum of Art, 19 (2): p. 35.