About Natural Whetstones

What are Natural Whetstones?

A whetstone is a tool for polishing the surfaces of metal, wood, rocks and so on. Since the Stone Age, natural whetstones made from natural rocks have been used as important tools. Old whetstones have been excavated from ruins from all around the world. Towards the end of the 19th century, demand for natural whetstones decreased rapidly with the development of artificial whetstones such that production now has been reduced to just a few companies.

Grades of Natural Whetstones

There are various ways to classify natural whetstones but they are generally divided into the following grades based on grit size (grit refers to tiny particles in the stone which grind the workpiece) in descending order from large to small ? the "rough stone" (ara-to), the "middle/medium stone" (naka-to) and the “finishing stone” (shiage-to). The finishing stone is also referred to as the “matching stone” (awase-do).

Distribution of Natural Whetstones

Natural whetstones were produced from all over Japan. Among them, the “Tamba Ao-to” produced in Kameoka city was one of the most famous medium grade stone. In addition, finishing stones produced in Kyoto city and Kameoka city stood out above the rest in terms of quality and quantity. Even now, this city remains among the precious few places in the country that produces these natural whetstones.

Japanese Culture & Natural Whetstones

atural whetstones in Japan were mentioned for the first time in the “Shosoin Treasure Repository” (shosoin monjo) historical record (Nara Period). By this time, the term “Ao-to” (medium grade stone) was already in usage. After that, for over 1000 years, natural whetstones played a key supporting role for the sharp blades that were indispensable to Japan’s unique traditional culture and crafts. The beautiful wooden architectural structures in Kyoto and elsewhere in Japan for example. In order to give the wooden building materials a smooth finishing, it was necessary to sharpen the hand plane (a tool used for shaping wood) with a natural whetstone. Another example is Washoku (Japanese cuisine) which is registered as a UNESCO Intangible Cultural Heritage. In order to draw out the taste of the ingredients, it was essential to sharpen the Wabocho (Japanese kitchen knife) with the natural whetstone. Another is the Katana, the Japanese sword that gleams bewitchingly and transcends into a work of art. Even till this day, the natural whetstone is key in polishing and bringing out its mysterious shine.

The Natural Whetstone Takes Center Stage

Unfortunately, natural whetstones are hardly seen nowadays and are only used among some professionals and enthusiasts. In order to pass down this valuable natural whetstone culture as a historical heritage to future generations, and disseminate this aspect of Japanese traditional culture overseas, the “Natural Whetstone Museum” has opened this year in Kameoka, Kyoto. We look forward to your visit!