This is a rare natural medium-grit whetstone known as Shitomae-to, formerly quarried from Shitomaeyama and along the Shitomae River in Omyojin, Shizukuishi, Iwate Prefecture. It is also known as Shizukuishi-to and was traditionally used to sharpen agricultural implements, kitchen knives, Japanese woodworking tools, and other cutting tools.

Shitomae-to has a remarkably long history. During the Edo period, its high quality and value led the Morioka Domain, also known as the Nanbu Domain, to strictly control its quarrying and distribution. It was regarded as one of the region’s important specialty products. Quarrying and distribution continued after the Meiji period, but the spread of synthetic whetstones and declining demand for natural stones eventually brought production to an end. According to local records, Shitomaeyama ceased operating as a whetstone quarry in August 1959. Some remaining raw material continued to be processed and sold for a time, but these stocks have now been almost entirely depleted, making genuine Shitomae-to exceptionally scarce on today’s market.

The stone has a very dense structure with excellent stability and uniformity. There is minimal variation in sharpening feel and abrasive performance across the surface, allowing the blade to remain stable and easy to control throughout the sharpening process. Water absorption is moderate, enabling the stone to maintain a suitable working condition without absorbing water excessively.

It also provides ample cutting power, efficiently refining both the edge and blade surface. Despite its hard, dense structure, its response against the blade is easy to perceive, providing a stable and satisfying sharpening feel. It is well suited to the intermediate sharpening of kitchen knives, Japanese woodworking tools, and various carbon-steel blades, effectively refining the scratches left by coarser stones and creating a smooth transition to the final finishing stage.

Combining excellent density and uniformity, reliable sharpening performance, and ample cutting power with a distinguished history of quarrying and distribution under the control of the Nanbu Domain, this rare Shitomae-to holds considerable value both as a highly practical natural whetstone and as an important historical piece.