This is a very striking and interesting necklace my Presidium Gem tester says that this dark green marbled stone is some-sort of gem maybe even man-made It is really believe it is so pretty It is so cold and beautiful and has some lovely lines. The dark beads are onyx. The closure is a toggle. The length is 21 inches and green beads are over 1 1/2 inch and an inch wide. It lays beautifully on your neck and would be perfect on a black jewel neck sheath! WoW. To you from Kansas Beautiful Necklace.