Antique American Indian Art, LLC. Navajo Sterling Silver and Turquoise Necklace, Signed. Navajo Sterling Silver and Turquoise Necklace, Signed “GM” hallmark. With striking leaf work around stone settings, nice weight and rounded beads. A handsome necklace overall. Sterling Silver and Turquoise. We are confident that you will be pleased with the value, service and peace-of-mind that our gallery can offer you. Thank you for looking! We will be adding lots of quality Antique American Indian Art over the next few months.