Powder of feldspar or feldspar-bearing rocks, an important raw material for ceramics. Ishiko is also called Hiromi in Owari and Mino (Aichi and Gifu prefectures). It is probably due to the high quality produced from Hiromi Village, Nishikamo County, Mikawa Province (Toyota City, Aichi Prefecture). Glaze powder is of high quality and is mainly used for glazes, while jiko is of inferior quality and is mainly used for base materials. Jiko is of inferior quality and is mainly used for the base. The watery substance is called powder.
The primary production areas are Aichi and Gifu prefectures, with Shiga, Ibaraki, Ehime, and other prefectures also producing stone powders. The purpose of using stone powder is to take advantage of its alkali content, and therefore, good quality stone powder should be close to pure feldspar and have low iron content.
