Indian/African delicate silver necklace with sphere bell pendant w/ purple stone

Necklace with a round/sphere bell pendant with a purple stone on the bottom No markings to indicate material, but I'm guessing it's sterling or silver plate since it tarnishes and can be polished Chain is adjustable from 20-22" and the pendant is 1/2" wide and long Excellent condition My mother-in-law bought this while traveling in Africa and India -- I don't know the exact country it's from, but I think it's most likely India. I have more jewelry from her travels in my closet!