Custom Native American Shell Necklace with Turquoise and Spiny Oyster Shell. Item is 16" in Length and the Spiny Oyster Shell measures 3 1/2" x 3". The Turquoise stones measure 12mm wide. Has included Spiny Oyster and Turquoise Earrings. Item XN175.. $10 Cost for Shipping and Insurance in addition to price.