China Jiuquan Night-Glow Cup This is a traditional Chinese craft item, the Jiuquan Night-Glow Cup (yakouhai). Size: Diameter: Drinking rim: 4.5cm Base: 4cm Height: 8cm The Night-Glow Cup is made by hollowing out a rare stone mined in the Western Regions of China. Inferior products are made by molding stone scraps (powder). The way to tell them apart is that a genuine one will be attracted to a magnet, while an inferior product made of powder will not react. It said. I tried bringing a magnet close to it, and it reacted. It appears to be unused. There are no stains or scratches. It comes in a cosmetic box, but the box is dirty. It has been stored at home for a long time. Please refrain from purchasing if you are sensitive to such things.