The white whetstones at Iyo Meito are used to make ceramics such as Tobe ware. Among the white whetstones, however, those with a bluish white hue are called "Ao" and are hard and unsuitable as a raw material for ceramics. However, as a whetstone, they are hard and fine, so they function as a semi-finishing stone. Among Ao, the most outstanding pale blue stones are grayish in color, resembling the dark clouds that cover the mountains. "Murakumo"