About Natural Whetstone and Hone

What is Natural Whetstone?

A whetstone is a tool used to polish/grind the surface of metal, wood, stone, etc. Since the Stone Age, natural whetstones extracted from natural rocks have been important sharpening tools. 

With the development of artificial synthetic whetstones at the end of the 19th century, the use of natural whetstones has become rare.


Natural whetstones are classified into rough, medium, and finish stones according to the size of the abrasive grains . The finishing stones are also referred to as the "Awasedo" (matching stone).

Where is natural whetstone mined?

 "Tamba Aoto", a medium grid stone produced mainly in Kameoka Kyoto, is a high quality stone extracted from a stratum about 150 million years old. 

"Awasedo", extracted from a stratum about 250 million years old, is also excellent in both quality and quantity.


Kameoka Kyoto is one of the few important production sites of natural whetstones today.

How natural whetstones have contributed to Japanese culture ?

The first record of natural whetstones appears in the Shosoin documents (Nara period).

Since then, for more than 1,200 years, natural whetstones have contributed to the sharp cutting blades that are indispensable to Japan's unique traditional culture and traditional crafts.

In Kyoto, for example, there are many beautiful traditional wooden buildings. To smoothe and finish the woodit was necessary to sharpen planes with natural whetstones.

Japanese cuisine is listed as a UNESCO Intangible Cultural Heritage. To bring out the flavour of the ingredients, Japanese knives had to be sharpened with natural whetstones.

Japanese swords have an enchanting sheen and are considered works of art. Even today, this mysterious beauty cannot be sharpened without a natural whetstone.

Natural whetstones for future

With the advent of artificial synthetic whetstones, the use of natural whetstones has declined.

However, the long-lasting sharpness and beautiful finish of natural whetstones continue to attract professionals and enthusiasts from all over the world.


The Natural Whetstone and Hone Museum is dedicated to passing on the culture of sharpening with precious natural whetstones to future generations and spreading it throughout the world.

At our museum you can see natural whetstones from all over Japan and the world. You can even experience sharpening your own knives with natural whetstones. Please feel the wonder of natural whetstones.