Antique / vintage Art Nouveau handmade filigree Yin Yang silver necklace

Vintage / antique Art Nouveau Yin Yang necklace. Could be over 100 years old. Possibly made of sterling silver, but not stamped, and I never tested it. The clasp on the chain has been replaced, perhaps the original one had some markings. 1.1" long pendant (with bail) 18" long chain.