Avon vtg Necklace Opalescent blue white silvertone vintage adjustable

Vintage iridescent teardrop necklace from Avon on a link chain with 10 clear faceted beads. I am not sure if the pendant is glass or crystal/stone; most likely a simulated moonstone. It is clear with a blue-based iridescent glow, very beautiful. Length is 18 inches, including a 3 inch extender. Pendant length (with chain attatchment) is 2 inches There is tarnishing on some of the links (see pictures). 0047