A small natural sharpening stone for tools. Medium grit (about #800-1000) from sharpening stone supplier, Fuchioka of Niigata Prefecture.
Details
Size: 15cm x 5cm x 3cm
Weight: Approx. 530g
Usage
Soak in water for a 10-30 minutes before sharpening to hydrate the stone. If sharpening multiple tools re-quench the stone as required. Once finished using, rinse with water, allow to dry and keep in a location which gets no direct sun or gets frozen in Winter by wrapping it with a cloth.
Origin

Japan
Sanjō is a city located in Niigata Prefecture, Japan. As of 1 July 2019, the city had an estimated population of 95,706 in 36,201 households, and a population density of 222 persons per km². The total area of the city was 431.97 square kilometres.