One silver Black Tourmaline on a 24" stainless steel ball chain. Black Tourmaline is a protective stone which repels and blocks negative energies as well as psychic attacks. Black Tourmaline also aids in the removal of negative energies within a person or a space. Perfect for men, women, teens and children. Stones measure approximately 1"-1.5" in length. Size and shape may vary as no two stones are alike.