Shobu Iromono Japanese Natural Sharpening Stone 1274.8g (2Lb.13.1oz. )
The company used to mine Shobu (it was one of them, I think that Shobu had been mined by more than one company. There were more than one ore port owned by more than one company) and the other name mines.
Shoubu-dani is the original mine to yield high quality Japanese sword sharpening whetstone in Kyoto, and the mine run out the production of the ore, and moved to the other mines, so Shobu-dani used to have really great final finish whetstones.
It is moderate hardness in fine grit whetstone (not too hard and not too soft), and it produces very good amount of black slurry quickly. It has very gently touch, when I sharpen the blade, and I felt little elasticity from the sharpening surface, so it is easy to work with. It should be good enough amount of slurry, so it does not need Tomo Nagura or a device that produces slurry.
(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)
Particle Size-------------- 8.8
(Scale; 1 to 10, 1-3 give deep scratch marks to the steel, 3-5 is delete the 1-3 scratches, 5-8 makes the steel cloudy, 8-10 makes the steel semi-mirror finish or mirror finish)
It makes my blue II steel blade knife Jigane to light bright silver color and Hagane became semi-mirror finish to mirror finish.
Shobu is located on close by infamous mines such as Okudo, Ozuku , Nakayama, and Narutaki, where is the east side of Atago mountain. It is original mine of Awasedo in Kyoto since 800 years ago.
Natural whetstone has wider capacity wider variety 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.