JP: 磁石/じせき
Raw material for porcelain products, also called Toseki. This material was discovered at Izumiyama quarry in Northern Kyushu in 1616.
The porcelain clay of Mount of Izumi (in Arita) and Amakusa is said to be a material unique to these areas. Its high quality makes it possible to create totally pure products without the need to mix with other materials.
