A different Yuteki Tenmoku Chawan, whose image I stole from the internets. (Specifically, this is a national treasure made in the 12th or 13th century)

Yuteki Tenmoku Chawan (Hoshi Kensan)
From the Collection of the Tokugawa Art Museum

The name “Hoshi Kensan (Star of Fujian)” was passed down from old by the House of Tokugawa of Bishuu. A ring (fukurin) of sahari copper along with a complicated pattern of variously sized oil drops surround the rim, partially making a grain awn pattern.