Ohira Uchigumori 4 pieces of stones: 8.9oz. (249.2g) Japanese Natural Sharpening Stones
All of them have 50-60mm with a longest side
They are small pieces, so they are good for making finger stones by breaking down.
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, but it might have pigment or oxidized substance so that it gives the Jigane and Hagane vivid color, and it is not super fine, so it deletes or hides the scratches as well. If you have experience after used finest grit hone, and it leaves scratches and ugly finish, Uchigumori might help delete or hide the scratches, 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 than Hato and smaller particles of slurry, and it is heavier than Hato. It gives great result for Japanese sword Jigane finishing process.
It is also great result to make up Jigane for kasumi look or Damascus look.
Natural whetstone has wider capacity than artificial whetstone, and actually, we do not know until sharpening for a while.
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 molecules, and make Jigane as suitable Jigane color, and Hagane as suitable Hagane color. It is natural mystics.