Camphor（By preserving specific wood grain cuts.）

It is an ingenious Go bowl, which shines according to the changing light. 
Camphor has a strong fragrance that can repel insects, making it   a common material for furniture such as chests of drawers. The color of the   wood is calm and lustrous, presenting a sense of luxury.
 
There is the auther's brand”懷志” on the back.