Thread: Tsushima "Ocean Blue" 12K

Many of the standard productions razors like Dovo and Boker have a edge length of about 70mm, about 2 3/4". However, there are some razors that are close to 3" and having a 2.7" wide hone is helpful. I am not sure that going to a 3.2" wide hone is necessary for a razor, although it might be useful on a chefs knife. Since I am using it for razors, I purchased the 8" x 2.7" size.

I know that some people have even tried honing on Nagura size stones, but it seems to me that your technique would have to be spot on to keep uniform pressure across the width of the blade on that small a stone. It is a little easier with a stone whose width is close to the length of the blade.

Originally Posted by Marshal

Large stone dimensions: 8.0 x 2.7 x 1.0 Total Volume: 21.6
XLarge stone dimensions: 8.0 x 3.2 x 1.1 Total volume: 28.16

Large stone $4.03 per cubic inch
XLarge stone $4.43 per cubic inch

I'm still not sure what the heck the sizes are. If you look in different places, they give two different dimensions for both stones. For the 'L' size one size given is 2.7" x 8" x 1" and in another place it says 2.7" x 8" x 1.2" and 950g weight. For the larger size one (XL) one size given is 3.2" x 8" x 20mm (.79") and 900g weight and the other is 3.2" x 8" x 1.1" so who knows!

Edit: that was yesterday - it now appears that they have edited the description of the 'XL' stone now so it is 3.2" x 8" x 1.1" and 1250g. The 'L' stone still has two sizes given in the listing varying in thickness.

These are natural stones so no 2 are identical. There may be more than one vein or stratum under the ocean. Every one having its own characteristics. Petty amazing they extract hones below the ocean floor.
Here's some more info on the names and colours of the stones: Tsushima Black Nagura | TomoNagura.Com | Keith V. Johnson

As with all natural stones: you need to get the from a knowledgeable seller who can recoomend a stone that suits your purpose.

Any natural quarry can contain stones of different quality. The Belgium quarry that yields yellow Coticules also yields Belgium Blue, two stones that are different and serve different purposes. Sometimes the layers are adjacent so that they can produce a yellow Coticule backed by a Belgium Blue without using an adhesive between them; unusual, but they do exist.

Here are Tsushima stones. The big one is a "Sea" stone from So Yamashita. The smaller one is a "Mountain" stone from Dr. Naka.
Both exhibit similar mid range performance characteristics.
Mike

Yea, this is not the traditional Tsushima stone. It does appear to be a different stone, possibly of a different grit range and composition.

Not saying it is not a finisher, just that it is not the same stone.

We have seen this before, with folks labeling stones with the names of traditional stone.

They may be mined from Tsushima, but not from traditional sources.

The one plus is/are the Ortiz videos, he does appear to be knowledgeable and has posted, a lot of natural stone honing videos in the last year or so…

If you want to compare grit stria, Alex Gilmore at

The Japan Stone, has several very good videos comparing stria to know grits. Hard Japanese naturals usually produce a kasumi, hazy finish that cannot be compared conclusively.

Time, use and results, by others will tell.

Pay your money and take your chances, there are no magic stone…

Hey, there's the first natural stone I found in the wild! Brings back memories, lol.

Originally Posted by eKretz

Hey, there's the first natural stone I found in the wild! Brings back memories, lol.

That's very cool!

Originally Posted by eKretz

I'm still not sure what the heck the sizes are. If you look in different places, they give two different dimensions for both stones. For the 'L' size one size given is 2.7" x 8" x 1" and in another place it says 2.7" x 8" x 1.2" and 950g weight. For the larger size one (XL) one size given is 3.2" x 8" x 20mm (.79") and 900g weight and the other is 3.2" x 8" x 1.1" so who knows!

Edit: that was yesterday - it now appears that they have edited the description of the 'XL' stone now so it is 3.2" x 8" x 1.1" and 1250g. The 'L' stone still has two sizes given in the listing varying in thickness.

When I wrote my comment, the XL stone was listed at .8 thickness, and weighing in at 50gm LESS than the L stone.

Originally Posted by Magpie

When I wrote my comment, the XL stone was listed at .8 thickness, and weighing in at 50gm LESS than the L stone.

The large ocean blue stone I purchased was 7 3/4" L x 2 11/16" W x 15/16" thick with all measurements to 1/16". The weight was 949g.