Using gold wires, Byzantine goldsmiths worked the delicate filigree clasp on each of these necklaces. The Greeks wore amethyst, a violet colored quartz found in jewelry across the ancient world, as an amulet to protect against the effects of wine and poison and to keep them from harm in battle.
J. Pierpont Morgan, London and New York (until 1917)
Rorimer, James J., and William Holmes Forsyth. "The Medieval Galleries." The Metropolitan Museum of Art Bulletin, n.s., 12, no. 6 (February 1954). p. 126.