Thank you for viewing. - Material: Black Onyx, Silver - Brand: STUDIO TENTEN - Size: Inner diameter is 1.8cm, so I think it's about size 16. I purchased this new and stored it in the included bag and wooden box, hardly ever using it. This is an art jewelry piece that suits adult women and has a comforting, plump form. The designer is said to be inspired by the world heritage sites they saw through their travels. They also have pop-up stores in places like Ginza Mitsukoshi. I welcome any questions. #ring #blackonyx #blackonyx #powerstone #studiotenten