Tsushima Black Nagura

Tsushima Black 1

Tsushima Black Nagura Toishi 

This grey-black stone was quarried underwater on Tsushima Island off the coast of Nagasaki. This is the ‘Ocean’ variety of Tsushima Black. From another location, perhaps nearby (not sure to be honest), there was another type of Tsushima Black known as ‘Mountain Tsushima’.  I am not certain whether or not they are the same type of stone, but I’ve been told that the ‘Ocean’ variety is finer and more consistent.

Years ago, carpenters and woodworkers in the western hemisphere lovingly called these stones ‘Ocean Blue’ hones; they were used for the final finishing stages when sharpening their cutting tools.  

When used as a straight razor hone,  I placed the Tsushima in the middle of the progression; after Botan, and before Koma. This stone is quite hard and while the slurry starts off being medium-fine, it wlll break down considerably. I’ve also found that the Tsushima makes a good start point for touching up a razor; the cutting action is a bit slow but very effective. Straight razor edges finished on Tsushima Black slurry may shave, but they will not shave like they do off a real finisher. TBN edges are, in all reality, in a pre-finish state. 

Essentially, these are mid-range stones that can get you close to a shaving edge but they are not finishers in the traditional sense. There are vendors claiming that these stones are equvalent to 12k synthetics and that is, simply, a lie. They are not 12k, they aren’t even close to being 12k. If I had to assign a grit number, I’d say 7k. 

The sides of the stone are sealed with Cashew Urushi, which helps to seal out water. These stones must be sealed and never soaked or they will fissure and split. When sealed, and treated well – they can last several lifetimes as a razor hone.

Click here to view a clip of a Tsushima Black Nagura Toishi in action.

Approx. Dimensions: 7.2 x 2.2 x 2.0 / 183 x 56 x 51 mm

Weight: 3.1 lb / 1.4 kg

© Keith V Johnson 2014 - 2018