This is a natural finishing whetstone from Shoubudani, Kyoto, known as "Gosenryo.（五千両）"Daigokujō (大極上) indicates the highest grade available, signifying exceptional quality and performance."

Shoubudani is one of Kyoto's most respected natural whetstone-producing areas, alongside famous regions such as Nakayama and Okudo. For generations, it has produced high-quality finishing stones used for sharpening swords, kitchen knives, planes, chisels, and other edged tools.

The name "Gosenryo" is relatively well known among natural whetstone enthusiasts. However, unlike geological layer names such as Tomae, Suita, or Asagi, "Gosenryo" is generally regarded as the name of a quarry section, a trade name, or a traditional designation rather than a specific geological stratum. Surviving historical records are limited, but among old Kyoto whetstone dealers and collectors, names such as "Shoubudani," "Choushirou," "Ushike," and "Gosenryo" are often mentioned together.

Some collectors believe that "Gosenryo" referred to a specific quarry face associated with the Choushirou workings, while others interpret it as a designation reserved for particularly high-grade stones within the Choushirou production. Because detailed quarry records no longer exist, it is difficult to confirm either theory. Nevertheless, the name has long been associated with high-quality Shoubudani stones.

One popular explanation for the origin of the name is that the stones produced there were considered valuable enough to be worth "five thousand ryo," a substantial fortune in old Japan. During the Edo period through the early Showa era, mines and quarry sites were often given auspicious names such as "Senryo" (One Thousand Ryo), "Manryo" (Ten Thousand Ryo), and "Hozan" (Treasure Mountain). "Gosenryo" is thought to follow this tradition.

This stone was acquired from a Japanese natural whetstone collector. During sharpening tests, it displayed a pleasant degree of cushioning along with a soft and refined sharpening feel. A delicate gray slurry was continuously generated, allowing the blade to glide smoothly across the surface while producing a natural and elegant kasumi finish.

Today, high-quality Shoubudani stones have become increasingly scarce, and opportunities to acquire stones bearing the historic "Gosenryo" designation are even rarer. This piece is appealing not only as a practical sharpening stone but also as a collector's item that preserves a fascinating part of Kyoto's natural whetstone history and culture.

During sharpening tests, this stone exhibited a sharpening feel remarkably similar to that of a high-quality vintage Nakayama. Despite its hardness, it offers a surprisingly gentle and smooth feel against the edge, while generating a rich black slurry. The swarf is released exceptionally well, preventing the surface from loading up and allowing for a clean, efficient sharpening experience. Overall, it is an excellent whetstone with both refined performance and outstanding usability.

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 : 70-82mm×120-136mm×15-25mm ( Approx.) 

Weight: 678g