Natural Stones

Brand: Tanaka Toishi 田中砥石工業所
Dimensions: 220mm x 82mm x 45mm
Weight: 1573g

Notes: Really nice specimen from the famous Mikawa mine in Aichi Prefecture via the famous Tanaka Toishi brand. They are firm to hard, and quality specimens are fast and give good polishing results. Generally easy to use depending on the hardness.

Suggested Use: pre or final polisher for knives and push-cut tools.

Background Info: Nagura is made of lithified tuff, which is silica-rich stratified volcanic ash that has been compacted into a solid over many, many years. They contain very fine particles of silica (and other  which are often more friable than other sedimentary stones, and thus are ideal for polishing. They are used as one of the last stones before Uchigumori in a traditional sword polishing sequence. The word "Nagura" is the named after the individual who discovered the utility of the lithified tuff as a whetstone, Sakon Nagura, over 700 years ago.

Please Note: Given the natural aspect of these stones, all subjective qualities are our estimates and may vary slightly from your exact expectations and assessment. The images shown and characteristics described may be from a previous example. If purchased, yours may differ slightly in appearance and qualities. Dimensions, weight, and stamps may be different from listed if it has been tested.

Brand: Tanaka Toishi 田中砥石工業所
Dimensions: 225mm x 86mm x 44mm
Weight: 1615g

Notes: Really nice specimen from the famous Mikawa mine in Aichi Prefecture via the famous Tanaka Toishi brand. They are firm to hard, and quality specimens are fast and give good polishing results. Generally easy to use depending on the hardness.

Suggested Use: pre or final polisher for knives and push-cut tools.

Background Info: Nagura is made of lithified tuff, which is silica-rich stratified volcanic ash that has been compacted into a solid over many, many years. They contain very fine particles of silica (and other  which are often more friable than other sedimentary stones, and thus are ideal for polishing. They are used as one of the last stones before Uchigumori in a traditional sword polishing sequence. The word "Nagura" is the named after the individual who discovered the utility of the lithified tuff as a whetstone, Sakon Nagura, over 700 years ago.

Please Note: Given the natural aspect of these stones, all subjective qualities are our estimates and may vary slightly from your exact expectations and assessment. The images shown and characteristics described may be from a previous example. If purchased, yours may differ slightly in appearance and qualities. Dimensions, weight, and stamps may be different from listed if it has been tested.