This is an authentic, rare Ammonite and sterling silver bracelet. The size of the bracelet is adjustable and can fit most wrists. The size of the Ammonite is 2.5" x 2". Ammonites are an extinct group of marine invertebrate animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs are more closely related to living coleoids (i.e. octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species. The weight of this adjustable bangle is 141 grams.