Earrings like these are found throughout the Byzantine world.
Found near Assiut, Egypt (?); [ Maurice Nahman, Cairo (sold 1912)]; J. Pierpont Morgan, London and New York (1912–1913)
Dennison, Walter. A Gold Treasure of the Late Roman Period from Egypt. Studies in East Christian and Roman Art, Vol. 2. London and New York: University of Michigan Studies-Humanistic Series, 1918. no. 16, 17, p. 151, fig. XLI.
Wagner de Kertesz, Margarita. Historia Universal de las Joyas. Buenos Aires: Ediciones Centurion, 1947. p. 269.
Weitzmann, Kurt, ed. Age of Spirituality: Late Antique and Early Christian Art, Third to Seventh Century. New York: The Metropolitan Museum of Art, 1979. no. 306, pp. 327-328.
Brown, Katharine R., Dafydd Kidd, and Charles T. Little, ed. From Attila to Charlemagne: Arts of the Early Medieval Period in the Metropolitan Museum of Art. New York and New Haven: The Metropolitan Museum of Art, 2000. p. 62, 341, fig. 7.4.
Spier, Jeffrey. Byzantium and the West: Jewelry in the First Millenium. Paris, Chicago and New York: Les Enluminures, 2012. pp. 29–30, 99.