Turquoise, Onyx Necklace

Beautiful turquoise and onyx necklace. I bought this at an art fair. Also, am not certain what I paid for it and it could be manmade stones. I just don't know. Really like it but never wear it. Sooo, maybe someone else can get some enjoyment out of this necklace. Excellent condition. I'd say a person should have a somewhat smaller neck as it's about 16".