This is a beautiful necklace fashioned from black onyx and accented with turquoise magnesite and sterling silver. Magnesite is a natural gemstone, and has been dyed turquoise to simulate natural turquoise, which it does quite beautifully, and is not nearly as expensive! The necklace is 16" long, extendable to 19" and the extender chain is nicely finished with an onyx bead. The necklace is knotted for security.