Looks like a tooth cut in half or tusk to allow it lay flat. It has a Mayan god or warrior image made of sterling silver and hangs on a large handmade bail. The chain is marked Peyco, .925. This was a jewelry company from back in the 1960's that was located in the Central American area. Chain has a nice weight, very unisex, weighs 10.7 grams and it measures 24" long. The ivory measures 2" long, 1" wide, and with the bail it has a drop length of 2-3/4", and weighs 11.8 grams. Great condition, lots of yellowing to the ivory and dark patina to the sterling silver. Very nice and interesting piece for your collection.