Vintage Southwestern Sterling Silver Beaded Choker Necklace

This is an older necklace which has been tested as sterling silver with the exception of the second round bead from the loop end of the necklace. It is a charcoal gray and I have no idea of what it is made of. The largest polished bead at the bottom is 11mm as are the large fluted disc beads on either side of it. The necklace measures 14 1/4 inches in length and it is strung on clear plastic wire. It weighs 24 grams and it is in great vintage condition.