Asano Stamped Mikawa Shiro Nagura
Koma Nagura, along with Botan, Yae Botan, Mejiro, Tenjyou, Atsu and Ban Nagura are use to raise abrasive slurry on a single Honzan or Tennen Toishi. Botan and Yae Botan are coarse, Mejiro and Tenjyou are finer, and Koma is the finest. Ban and Atsu are also coarse, and seemingly quite rare.
Chu Nagura has been quarried at many different locations, including Aichi prefecture but, apparently - not at the location where the Asano Stamped Nagura come from. Due to the obvious geological, practical and visual similarities between Chu and Mikawa Shiro Nagura, I’ve included them here.