Probably an iolite (^^; necklace top. A silver chain is not included. It's about 20 years old, but I remember buying it back then because it was a natural stone. I couldn't capture the actual color well in the photos, but it has a transparency and a blue-violet color. It looks like tanzanite or amethyst, but it's definitely not amethyst. I would be happy to pass it on to someone who likes it. Thank you. ※Additional Information※ The bale tends to rotate easily, so I used to bend the back part slightly. - Color: Natural stone - Material: Platinum 900 - Design: Pendant type #NaturalStone #Necklace #Pendant #NecklaceTop #Iolite #pt900 #Engraved