Ebony Onyx & Rectangle agate gemstone, changes color in the sunlight, Onyx in jet black faceted rectangle drops, Black Onyx is known to aid emotional and physical strength and stamina, especially during times of stress...this necklace is approximately 23 inches in length, this sterling silver necklace (with non-tarnishing coating) has this pendant drop 4 inches in length, with a silver plated lobster clasp and a silvertone heart charm.