This is an Aiiwatani Karasu finishing stone from Kyoto, near the border of Shiga Prefecture. Distinctive black Karasu patterns can be seen not only on the sharpening surface but also along the sides, reflecting the characteristic appearance of this quarry.

It can be used with confidence as a finishing stone for straight razors, traditional woodworking tools such as planes and chisels, as well as kitchen knives.

Although of moderate hardness, the stone is exceptionally dense and tightly structured, with relatively slow water absorption. Once sharpening begins, a fine slurry quickly develops beneath the smooth sharpening feel, guiding the edge toward a highly uniform and refined finish. One of its notable characteristics is its stable and well-balanced cutting action, providing effective sharpening performance without introducing excessive harshness to the edge.

As the flat area on the bottom of the stone is somewhat limited, we recommend using it on a damp towel or mounting it to a wooden base to improve stability and prevent wobbling during use.

A straightforward and honest finishing stone, well suited for users who value practical performance and sharpening quality over flashy appearance.

 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 sizes are not accurate. This is a lifetime investment for people who live sharpening their knives and tools, do not hesitate to ask me your questions.”

Dimension & Weight: 

52-75mm x 77-151mm x 5-30mm / 706g

All you can see on the picture will be included in a set of a package.


Please refer to the pictures for more details.
Please check the pictures and don't hesitate to ask any questions about the item !
Thank you.