The black beads are all onyx. The other grayish, tan beads are coprolite, fossilized dinosaur dung. Onyx always brings out the best in any stone it is paired with. This necklace is no exception; the onyx makes the coprolite look good. Casual and elegant at the same time and good for an interesting conversation. This necklace is 18 inches long and comes with a 2-inch extender chain it is finished with rose gold filled hardware.