This is a natural Kozaki Aoto quarried in the Kozaki area of the Tamba region, Kyoto, Japan.

Kozaki has long been recognized as one of Kyoto's traditional natural whetstone-producing areas, yielding a wide variety of stones ranging from Aoto to fine finishing Awasedo. This particular stone is a highly practical Aoto, ideally suited for the medium-finishing to pre-finishing stages of sharpening kitchen knives, planes, chisels, and other edged tools. It is especially well suited for single-bevel knives, allowing the user to refine the edge while enjoying the smooth, pleasant sharpening feel that is characteristic of natural stones.

Compared with a typical Aoto, this stone is somewhat harder and denser. Even so, it absorbs water relatively quickly. Once adequately saturated, the sharpening surface remains stable throughout use, providing a calm, predictable, and well-controlled sharpening experience. It also releases swarf efficiently, minimizing loading and allowing for comfortable sharpening over extended periods.

During use, the stone generates a fine slurry while maintaining excellent cutting performance. It refines the edge smoothly without being overly aggressive. It performs particularly well after a synthetic stone in the #1000 grit range, serving as an excellent bridge between coarse sharpening and the final finishing stages. It also transitions exceptionally well to natural finishing stones.

The stone excels at producing a practical working edge with a pleasant level of bite and cutting aggression. Whether used as a preparatory step before a finishing stone or as the final sharpening stone for those who prefer a toothier edge, it offers outstanding versatility. It is also an excellent choice for establishing the foundation of a beautiful kasumi finish, naturally enhancing the contrast between the hagane (hard steel) and jigane (soft iron cladding).

Today, high-quality Kozaki Aoto stones have become increasingly difficult to obtain. This stone is valuable not only as an outstanding practical sharpening tool but also as an important example of the natural whetstone heritage of Kyoto's Tamba region.

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 tools, do not hesitate to ask me your questions.”

Dimension :58mm×202mm×58mm ( Approx.) 

Weight: 1672g