Tennen Toishi

Maruka Stamp.jpg

Japanese Tennen Toishi are quarried from many different strata in the Hon-Kuchi Naori around Kyoto. Each stone has it’s own unique personality, and aside from the most obvious characteristic of color, there are varying degrees of hardness and various patterns.  What matters most is the stone’s performance. Visual aesthetics and identifying strata take a back seat to the finished results.   

Only select Toishi can be accurately classified as Awasedo. Many stones are too soft or coarse with uneven grit and are better suited for early-to-mid range honing.  Stones that are classified as a finisher for kitchen cutlery may only be useful as a mid-range Nakato stone when honing a straight razor.   

There are a few performance qualities that weigh into stone selection. Arguably, how fine a stone is, and the level of feedback it imparts to the user, is directly related to my main points of consideration; hardness and speed.  

Hardness, in and of itself, does not make a stone ‘better’. The same applies to any one quality actually. Typically, the best stone has a blend of qualities that are harmonious with my personality. Very keen edges can be created on very hard stones – but some very hard stones are just bricks without much abrasive content. So hardness has to include speed. After that, the subtle nuances of the stone’s personality determine whether or not I can get in-sync with it. Each stone is a sum of its parts. A perfect situation is when the stone becomes an extension of my honing skills.   

There were once many active mines producing these sharpening stones. In early history, swords were the weapons of choice by necessity. It only makes sense that the best edges would be sharpened on the finest whetstones. 

As time and civilizations progressed – the need for these whetstones decreased and many mines have closed; comparatively, few quarries remain in operation today. 

Tennen Toishi quarried at Nakayama and Shobudani can be found with the Sho Honyama Awasedo stamp; this mark translates to “Original Mountain Finishing Stone”. These have been the most famous and highly regarded stones throughout history. 

It’s worth noting that not every stone from those two mines is guaranteed to produce the desired result, and there are stones from other mines that are equally good and possibly better for someone. It all comes down to one simple fact; each stone is different and each stone must be tested to evaluate it accurately. 


© Keith V Johnson 2014 - 2018