This necklace was hand strung in Tucson, Arizona using Grade AA Spiney Oyster shell, genuine turquoise ends and sterling silver clasps. It is 18.25 inches and has a lobster claw clasp in sterling silver. The Spiny Oyster gemstone is a colorful shell that comes from the oyster species “Spondylus varius”, as the name implies, Spiny Oysters are covered with menacing spines. Spiny Oyster shells are unique, beautiful, and also difficult-to-harvest.