Unknown Medium Grit Japanese Natural Sharpening Stone 2lb. 6oz. (1076g)
It is used natural sharpening stone, so I do not know where it came from, but it should be Aoto.
It raises great amount of slurry quickly.
It is soft stone, but it is not too soft to be muddy.
It is easy to sharpen the blade, and fun to sharpen.
(Scale; 1 to 10, 1-3 is very soft muddy rough grit whetstone, 3-6 is soft medium grit whetstone, 6-8 is hard medium grit whetstone; 8-10 is fine grit whetstone)
It makes my blue II steel kasumi blade knife Jigane became very nice deep frosted silver color finish, and Hagane became light silver frosted color finish.
(Scale; 1 to 10, 1-3 give deep scratch marks to the steel, 3-5 is delete the 1-3 scratches, 5-8 makes 3the steel cloudy, 8-10 makes the steel semi-mirror finish or mirror finish)
Natural whetstone has wider capacity than artificial whetstone, and actually, we do not know until sharpen blade on the hone for a while. Because artificial whetstone molecules do not break down to smaller sizes, but Natural whetstone molecules are possible to break down to smaller sizes, and those molecules are mixed with sharpened steel molecules, and make Jigane as suitable Jigane color, and Hagane as suitable Hagane color. It is natural mystics.