Mikawa Nagura 1759g with corresponding reduction in resistance

with corresponding reduction in resistance to wear

This stone is hard and not as friable as other examples

The mine has been closed since the 1970s

The diamond layer is 10mm thick after firing

does not differentially absorb water

Mikawa Nagura 1759g with corresponding reduction in resistanceMikawa Nagura are Tuff stones, a type of igneous rock formed from lithified volcanic ash. Mined in Aichi prefecture starting 700 years ago, they have been used in traditional Japanese sword polishing progressions. The mine has been closed since the 1970s. We receive the stones from the wholesaler with rough chisel marks on both sides, and flatten them in our workshop. Although we have made a good effort to provide a flat surface for usage, we strongly