The stone appears to be cubic zirconia. There are no markings, and the material is unknown, so I am listing it as a fashion accessory. It has a delicate design, and it's an easy-to-wear ring, either on its own or layered. There are no noticeable scratches or discoloration, and it is in overall good condition. 【Size】 ・Inner diameter: Approximately 18-18.5mm (Approximate Japanese size: around size 13) *Please note that there may be slight variations due to amateur measurements. *Please only purchase if you understand that this is a used item and has been stored at home.