Thread: Japanese Natural Waterstones: What's in the name?

Forgive me if this has already addressed, but I have been wanting to further educate myself on the JNAT's for straights. I understand that my Nakayama Asagi came from the Nakayama mine, but I see so many other names after the mine name like Asagi, Kiita, Tomae, and so on. Where do these fall grit wise? I know we can't rate a natural by grit, but is there an "order" that these and I am sure others fall in? Aoto is on the opposite end of the scale I know compared to my Asagi. Then you get into the nagura'a...is there a scale for those? Any information or links provided would be most appreciated.

Btw...a light thuringian slurry gradually thinned to just water on an Asagi is simply awesome! Just tried it on a Torry yesterday.

My understanding is that the names vary in their meaning. I believe some describe the color (such as asagi), while others describe the strata, and I'm sure others mean other things as well.

If you go to So's website, he has a nice write up that at least attempts to generalize some of the vast info and history on Jnats and there divisions based on mines.

I am sure many of us would line up for a book written on them. Until that is done the best information is going to come from So, Alex and probably a handful of living souls.

I am glad you tried the thurri-slurry.

Thanks guys. I guess I didn't save his website in my favorites...got the link?

check this one too
About Natural Stones

Natural stones do not have grit, and Jnats also have break down of the grit particles as you use the slurry.
The classification of Jnats varies, I think most used system is lvl 1-5, both for hardness and fineness. But those do not mean much unless you try the stone and see for yourself if it is good for you.

That's what I was looking for. I had seen it before quite a while back, just lost the link. He gives about the best description I've seen on stones.

Originally Posted by mainaman

check this one too
About Natural Stones

Natural stones do not have grit, and Jnats also have break down of the grit particles as you use the slurry.
The classification of Jnats varies, I think most used system is lvl 1-5, both for hardness and fineness. But those do not mean much unless you try the stone and see for yourself if it is good for you.

There is no "most used" system, everyone who puts numbers (or letters) on a stone uses their own. Even if they happen to have the same numbers (for example, 1-5) there is no standard way to decide those numbers. They might as well just use "kind of expensive-really expensive".

Originally Posted by JimR

There is no "most used" system, everyone who puts numbers (or letters) on a stone uses their own. Even if they happen to have the same numbers (for example, 1-5) there is no standard way to decide those numbers. They might as well just use "kind of expensive-really expensive".

It is the one I have seen used the most, what it means is open to interpretation of course.

Mo Links.....
Japan Tool - Technique&Knowledge - Natural Stone Mines
Japan Tool - Technique&Knowledge - Awasedo

There are only generalisations & then exceptions to the rule. Generally, Hon kuchi Naori stones would fall into the finisher /prefinisher class but I've used an Aoto that would rival an 8k's finish. Most would say Aoto is 1-4k so it's not as simple as all '8k Shaptons are the same' but it makes naturals more fun.

Originally Posted by JimR

There is no "most used" system, everyone who puts numbers (or letters) on a stone uses their own. Even if they happen to have the same numbers (for example, 1-5) there is no standard way to decide those numbers. They might as well just use "kind of expensive-really expensive".

Maybe no book or standardization will ever be made to satisfy a very small minority of craftsman(including razor sharpeners). Certainly it would not do justice. Some things just take a long time with no instant answers available.

No doubt some of the most enlightened craftsmen of all cultures wondered about the same things but manifesting their products was much more important and through much of history knowledge in the arts was guarded.