Vintage Silver Toned Knot Necklace

Vintage Knot Necklace is such a unique piece. Minor surface scratches throughout and on closure, snake chain with twist barrel closure. Necklace is one piece and does not unknot. Silver toned but not real silver. I don't know a lot about this necklace other than it was purchased by my grandma and found prior to her estate sale. Questions? Please ask prior to purchase.