All 36 inches of Sterling Silver and it's a whole lot of gorgeous.  I've made a similar necklace before, but this has much more hardware than the previous pieces.  Each Sterling Silver disc is not lightweight.  That does not mean this necklace is heavy, it means that this necklace is substantial.  Lots of Sterling beads and accents are wire-wrapped throughout the two different chains used.  This is perfect for those who like long necklaces, or like wearing something over a big bulky turtleneck.  100% Sterling and you can even adjust the length to being shorter if you wish.