This is a rare Japanese natural whetstone (Aoto) from Okahana, Kameoka City, Kyoto Prefecture, known as Tamba Aoto.
It features a deep blue-black color with numerous “goma” speckles. Slightly harder than typical Aoto, yet it reacts quickly, raises a moderate slurry, and provides a smooth sharpening feel—very easy to handle.
Weight: approx. 3935 g
Dimensions: length 21.8 cm, width 7.0–8.6 cm, thickness 8.2–8.4 cm
Form: Shaped while leaving part of the natural split surface, so the width is not perfectly uniform
Condition: No cracks or dangerous lines observed, overall homogeneous and stable
Protection: Only the sides have been sealed with Ishisan water-based protective coating for whetstones. Top and bottom remain unsealed.
Okahana Tamba Aoto of this size and quality is extremely difficult to obtain today, as mining has long ceased.
A rare opportunity for serious sharpeners and collectors—suitable for kitchen knives, chisels, and woodworking planes.
