Ohira Uchigumori 1lb. 14.2oz. (857g) Japanese Natural Sharpening Stone
247mmX25-75mmX30-33mm
The sharpening surface is already flattened, but the bottom is not flat, so it might need a wood block to level the stone.
In general speaking, Uchigumori is soft hone, and lines are very soft, so they do not bother for sharpening.
Ohira Uchigumori is the one of the best quality of Uchigumori in Japan
Uchigumori is usually entry class of the fine grit hone, and I guess that it might have pigment or oxidized substance, so it gives the Jigane and Hagane vivid color.
It is also not super fine, therefore it deletes or hides the scratches.
If you have experienced after used finest grit hone, and it remains scratches and ugly finish, Uchigumori might help delete or hide the scratches before using the finest grit hone, and it makes little hazy very nice finish.
Ohira Uchigumori has Hato (Habiki) and Jito (Jibiki).
Hato is little softer than Jito, and it gives great result for Japanese sword Hagane finishing process. Jito is little bit harder and finer than Hato and smaller particles of slurry, and it is heavier or little more condensed than Hato is.
It gives great result for Japanese sword Jigane (soft iron) finishing process. It is also great result to make up Jigane for kasumi look or Damascus look. It also gives great result for high carbon stainless steel blade removing burr as finishing whetstone. 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 and contains single sharpening particles, but Natural whetstone molecules are possible to break down to smaller sizes, and there are variety of substances in there, and those molecules are mixed with sharpened steel and iron molecules, and make Jigane as suitable Jigane color, and Hagane as suitable Hagane color. It is natural mystics.