[Masamoto] Natural Whetstone Yama-Shiro, Ukyo Ward, Kyoto #69 /1,652g, 80 x 205 x 45mm #15069 Natural Stone

The invention of the Japanese sword led to the discovery of natural whetstones produced in Yamashiro Province, within present-day Kyoto City. Possessing a history of nearly 900 years, dating back to the late Heian period, it is known as the most refined and prestigious whetstone among slate-based whetstones.

It was a vital military resource throughout the age of the sword, managed by the ruling shogunate from the Kamakura to the late Edo periods. In terms of values until the modern era, it had a strong character as industrial materials, and in modern times, it could be said to be an essential resource for uranium mining, indispensable for nuclear weapons, and required strict management.

Iyo Province’s whetstones are believed to have already circulated through the Seto Inland Sea during the Kofun period, and are renowned as the leading producers of prestigious whetstones among the world’s oldest and largest igneous rock systems, with a history of over 1,500 years.

Our nation’s whetstone resources possess the power to change nations and peoples. Due to a lack of iron ore and the significant disadvantage in yield compared to sand iron smelting, and because of its remote location in the far reaches of the archipelago, Japan became the endpoint for the arrival of iron. This was a fatal condition for creating an iron civilization, as if losing limbs.

The very consumable resource that allows for the creation of harder and more resilient iron products at will is our nation’s whetstone resource, which can be proven by examining history and tradition. Despite poor locations for construction, it came to possess both the world’s oldest and largest wooden structures. Despite being a latecomer to the periphery, it achieved the invention of world-class iron products during the medieval period and continued the age of the sword for nearly 700 years.

Since most of recorded history belongs to the Iron Age, iron tools became our hands and feet, and the very medium for making things. It is natural that Japan is known today as a nation of craftsmanship, as it is proven that around the time of the ancient Asuka and Horyu-ji Temple construction, about 1,300 years ago, it was already capable of producing the world’s strongest iron products and tools.

It is a fact that even adversity like losing limbs was overcome in creating iron. The irreplaceable, rare, and unique support of our whetstone resources eliminated the rate-limiting step of whether sharpening was possible during steel development, by maximizing whetstone performance. In terms of assessing our nation’s various resources with values until the modern era, even though 70% of the land is covered in mountains and forests, it is a resource-rich nation.

However, it is only because the Japanese archipelago is crowded with five tectonic plates that we were allowed to extract whetstones in various places, in exchange for enduring numerous natural disasters. Our hearts, which accepted being dominated by mountainous and majestic natural environments that combine severity and abundance, may have gradually developed patience, cooperation, and compromise, and foreseen the existence of nature worship and the eight million gods (various resources and blessings), elevating them to the foundation of Shinto spirit. This is what will continue to tell the story of Japan’s greatest strengths and charms, which are relatively tolerant of foreign cultures and religions, and repeatedly repeat cycles of absorption and fusion, and are not limited to material happiness.

・80 x 205 x 45 mm, 1,652g, hard, for tools ・Good slurry emerges ・Siliceous slate from Ukyo Ward, Kyoto City, Yamashiro Province, #6,000~24,000 grit, hard. While a certain degree of kneading is required, the probability of refinement increases. Due to the continuous strip-like scratches on the rounded bottom, it tends to last for about 70% of its lifespan and is less likely to produce a mirror-like finish compared to artificial whetstone grit, making it easy to draw out contrasts derived from forging lines, material, and carbon content. ・The darker the rock juice, the harder and more refined the stone tends to be. Since hardness reduces self-sharpness, sharpen it gradually, performing name-kura-gake (a sharpening technique) as needed, depending on the purpose and kneading.

【Voltage Compatibility】 When using electrical appliances, please note that they are designed for Japanese voltage specifications (90-110V), so if you use them with a different voltage, it may cause a malfunction.

【Plug Type】 Our products use Japanese plug types (A or B type). Please use a conversion adapter if necessary.

【Important Note on Transformers and Adapters】 A transformer adjusts voltage to match your device's requirements. A conversion adapter only changes the plug shape and does not adjust voltage. Using only a conversion adapter without a transformer may result in damage to the product.

【Liability】 We are not responsible for malfunctions or damages caused by improper use, such as operating the product without a transformer.