This is an exceptionally rare Karasu natural finishing whetstone from Shoubudani, Kyoto, bearing the historic designation “Gosenryo” (五千両).

Shoubudani is highly regarded as one of Kyoto’s most prestigious and historically important natural whetstone-producing areas, alongside renowned locations such as Nakayama and Okudo. For generations, it has produced high-quality finishing stones used for polishing Japanese swords, kitchen knives, planes, chisels, and a wide variety of other edged tools.

The name “Gosenryo” is relatively well known among Japanese natural whetstone enthusiasts. However, unlike geological layer names such as Tomae, Suita, or Asagi, it is not generally considered to refer to a specific geological stratum. Rather, it is believed to have been the name of a particular quarry section, a trade designation, or a traditional name passed down over generations. Although surviving historical records are limited, names such as Shoubudani, Choushirou, Ushige, and Gosenryo are sometimes discussed in connection with one another by veteran Kyoto whetstone dealers and collectors.

Some collectors believe that “Gosenryo” referred to a particular quarry face associated with the Choushirou workings. Others suggest that it may have been a designation reserved for especially fine stones quarried from the Choushirou area. Since detailed mining records have not survived, neither interpretation can be conclusively verified. Nevertheless, it is clear that the name “Gosenryo” has long been associated with high-quality Shoubudani whetstones.

One widely known explanation for the origin of the name is that the stones produced there were considered so valuable that they were said to be worth “five thousand ryo,” an immense sum in historical Japanese currency. From the Edo period through the early Showa era, mines and quarry sites were sometimes given auspicious names such as Senryo (“one thousand ryo”), Manryo (“ten thousand ryo”), and Hozan (“treasure mountain”). Gosenryo is thought to have originated from this same naming tradition.

This particular stone was acquired from a Japanese natural whetstone collector and is believed to have come from the Aisa layer. Although Karasu stones are often relatively hard, this example is comparatively soft while still possessing a dense and refined structure. As a result, it responds readily and naturally when the blade is placed against its surface. These geological characteristics make it particularly interesting not only as a practical sharpening stone but also as a collector’s piece.

During sharpening tests, the stone exhibited a moderate degree of cushioning and a gentle, smooth sensation against the blade. It continuously generated a fine gray slurry, allowing the blade to travel smoothly across the sharpening surface while producing a natural and elegant kasumi finish.

Another notable characteristic is its excellent ability to manage slurry and metal swarf. The sharpening residue releases cleanly from the surface, making the stone highly resistant to loading or glazing during use and allowing it to maintain stable and consistent sharpening performance.

In recent years, high-quality Shoubudani stones have become increasingly difficult to obtain, and opportunities to encounter an example bearing the historic Gosenryo designation are even rarer. This stone is therefore not only an excellent and highly practical natural finishing stone, but also an appealing collectible that preserves a tangible connection to the history and culture of Kyoto’s natural whetstones.

Overall, this is an exceptionally fine natural finishing whetstone that combines outstanding sharpening performance, excellent practicality, and significant historical and collectible value.

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: 

81mm x 206mm x 24mm

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.