This is a set of Kyoko's Soul gem and ring.
Both were sold over 10 years ago. However, there is no damage such as scratches. (authentic.)
The ring is made of 925 silver smoked. And the front side is a synthetic ruby, and the back side is written with witch characters as "Kyoko".
As it is an official item, the quality is high as an item.
The size of the ring is 7.5 in American size.