Japanese Natural Whetstone Shohonyama Kizuyama Tomae 569g from Kyoto Japan

This is the Kizuyama Tomae from Kyoto Japan. Kizuyama located in South Narutaki ( Higashinoyama ) area, a mine that relatively stiff natural whetstone. Rare & Hard to find Kizuyama itself these days ! The hardness approx. 4.0, good for woodworking tools, knives. For Razor still OK as a pre-finisher.  Please note that these are not for beginner sharpeners since they're harder to use. These are natural stones meaning that every single one of them are different so my measured size are not accurate. This is a life time investment for people who lives sharpening their knives and tools.

Dimension  : 37-40mm×205mm×29mm ( Approx.) 

Weight: 569g

Grit size: Extremely fine 8000

Nagura is not needed but using one will definitely speed up the process

Excellent finishing stone for knives, woodworking tools, razors as a pre-finisher

Hardness: 4.0+

In last photo, production area in Kyoto shows

The grain size of Japanese lapping stones is quite relative, in any case it is thinner than synthetic stone # 8000. This will give the famous Kasumi coating (cloudy) and prolong the life of the blade. Finish sharpening is done on natural stones, and a smooth, sharp cutting edge is obtained. Japanese natural stones have such properties, because the quality is influenced not by the size of the abrasive particles, but by the shape. This is confirmed by a study by the University of Tokyo. SiO2 abrasive particles are in the form of rounded flakes. They do not abrade, but remove steel like sod, especially on suspension. Thus, not enough steel is removed, but the steel is also removed in such a way that an even jagged edge is not formed, which would be when sharpening on artificial stones.

Using natural stones will allow you to cut finer and at the same time extend the life of the edge. There is a good reason for this. In synthetic stones, the sharpening particles are equal in size, while in natural ones they are not. Consequently, a blade sharpened from synthetic stone will have an even height of serrated teeth, so once those teeth become dull, it will stop cutting completely, but ... when the height is different ... I think you understand my point. It's like shark teeth. They don't break right away.

Also, a natural stone sharpening has a hardening effect on the edge of the blade. This has been scientifically proven by the HRC testing machine, an experiment carried out by the renowned blacksmith Usui Kengo. In fact, the hardness was higher after polishing with a thin natural stone. As you can see, the point is not only in the achieved sharpness of natural stones. After you use natural stones, you will not want to switch to artificial ones.