Abbreviated name for frog clay. There are blue frog clay, white frog clay, black frog clay, and so on. It is said to be a rearrangement of primary kaolin produced by decomposition of granite. The name is derived from the translucent silica grains that resemble the eyeballs of frogs when they are moistened by rain. In the dialect of the Seto region, frogs are called “ga-iro. Later it became a generic name for the same type of clay. A major raw material for ceramics.
