Sterling Silver and Purple Faceted Gemstone Necklace India 925 tanzanite

Sterling Silver and Blue faceted gemstone Necklace India 925 stamped 51 925 They look like they could be faceted amethyst not really sure. They have a lot of sparkle to them. These are pre-owned and probably worn before. In very good condition. see all photos for best description. Another Seller said it could be tanzanite. 527