Mikawa Shiro Nagura Botan Tokyu(superb grade) 5.1oz. (146g) Japanese Natural Sharpening Stone

Mikawa Shiro Nagura Botan Tokyu(superb grade) 5.1oz. (146g) Japanese Natural Sharpening Stone Approximately 36mmx40-59mmx33mm It is pretty nice shape, color, and tiny dots It has Tokyu hand writing on the stone which means superb quality. Koma, Mejiro, and Tenjyo are fine grit layers of Mikawa Shiro Nagura. Mejiro is one lower grit or little more aggressive stone, but in Mikawa Shiro Nagura, the grit of Mejiro is very useful. According to Dr. Kuniichi Tawara who is a Metallurgy doctor, and very famous Japanese sword researcher, Koma molecule is 10 to 20 microns. It should be good for two processes before starting the fine grit sharpening. For razor sharpening, it is used two processes before sharpening by fine grit whetstone like Nakayama, Ozuku, Wakasa, etc.