This stone contains a karusu like pattern that usually comes from the Asia layer, the
presence of red renge and su (microscopic gas voids) indicate that this is a suita stone.
It is ink stamped NARUTAKI  HON YAMA AWASEDO (Narutaki Original Mountain
Sharpening Stone) at the upper right and at the lower left SAIKO JO (best quality) and
lower right in a circle YU (top quality). Judging from the small portion of kawa on one
corner this could very well be from the Narutaki mine which was closed up for good in the
1930s but was excavated in the 1950 to prepare for a building project and some
sharpening quality stone was removed at that time.

By any means a big chunky and really interesting stone, it is a level 10- hardness, is
stingy in giving up a slurry but with just clear water will produce black swarf in clear water
and leaves hard steel chrome bright. With a slurry stone and or a diamond plate
generated slurry the sharpening speed is greatly sped up.
Grit Fineness
Size 208-74-34
Price  $1200