Japanese Natural or just old stained synthetic?

Hi everyone,

Yet another stone question... I posted something about this one a while ago, but only included scans of the box (with the name "White Stone - Deluxe Hone)as I had no camera.

I am wondering if this stone is a japanese natural or a rather old and stained synthetic. Having thus far only handled heavy duty carborundum stones for chippy chisels, I'm not clued up on the finer stones. The lapped surface is fairly uniformly creamy, but with a few areas of red/pink. The back and sides are all square (which says synthetic to my novice mind), but stained/darker.

Any thoughts?

Cheers,
J.

Edit: Apologies for the deplorable image quality. Best I could do with a mighty 3 kilopixel webcam :)

It kind of looks like the white binsui Jnat I just got in the mail today, it is supposed to be around 1000 grit, and it is squared up like the one you show. I am in no way even close to knowing what I am talking about with Jnats though. Maybe I can take a picture of mine and post it for comparison. I was hoping to use mine for bevel setting but it looks like it might be a little rough for razors, i have yet to try it on a razor though. I did make about 5 laps with my pocketknife and the slurry worked up very easily. 330mate has red or white binsui's listed in his ebay store you could check there for more info and see if his photos look like your stone.

Send kevint a PM. He is very knowledgeable on most of the obscure j-nats IMO.

The size of the hone suggests to me that it could be a natural hone. If you make a synthetic hone of that hight, with that much material you could make three thinner hones. But if you are shaping natural rock then bigger can mean less work, you don't have to cut it into three pieces.

Alrighty,

With the input of the forum and after closer inspection, I'm now relatively convinced that it is indeed natural. the edges show faint vertical grooves that are suggestive of saw marks, and some of the small cracks on the corners look like they would be hard to make by accidentally bumping it against something. That and the fact that it was in the original box and in good condition, which probably means that whoever had it took good care of it, and was unlikely to have got the surfaces this dirty.

Now to work out what approx grit it might be :) A bit difficult without a bevel setter to get started on the blade (Still in the mail). Is there a way that someone can suggest to get a rough estimate on the grit?

Thanks again for all the input :)

Not a chance. Especially since with Japanese naturals, since they don't really fir the frit rating system.

The only way to figure it out is to try and see how it reacts. And even that will only give you an idea. If you really want to know, the only way is to send it to an expert like So Yamashita for appraisal. He or his father will probably be able to say what it is, where it comes from and when it was mined.

Of course, So is already overworked so that is probably not a realistic option. and it doesn't really matter from a practical perspective.
Give it a try and see where it will fit in your honing setup.

It looks like an Amukasa white. That would make it a potential bevel setter - a coarse stone.

I seem to remember someone describing a box like the one you have containing one of those.

I've lapped it nicely and given it a go on the razor, and it seems to cut reasonably well, with one major problem. Every now and then I get little grains of something appearing from nowhere that cause a tiny clink sound. When looking at the blade under the microscope, I notice small chips out of the leading edge. Looking at some other threads, I think there may be some inclusions in the stone that are coming out as I hone. Damn :( Guess I'll have to wait for my DMT 1200 after all.

Well that sounds just like the one I just received from 330mate. There was a little discussion on Jnat bevel setters a little way back. The red had been tried and found to have too many inclusions for razors. I decided to give it a go with the white one but it sounds like it to has too many inclusions also. The top surface of mine was very smooth but spotted, the bottom had areas where some of those spots(inclusions) had come out and left a small hole. I was going to try mine this evening, probably still will, just hoping that maybe my results will vary from yours but I am sceptical. Worse case I wont have to use my norton 1000 for knives.


Edit: One question for any hone pro's, Couldnt you still use these stones to remove lots of metal, then clean up the small nicks(if they are small enough) with a higher grit stone? Maybe add some tape to make sure the higher grit stone doesnt have to reform the bevel to remove the chips?

And i'm a little late but here is a pic of mine.

Yup, that one looks rather similar to mine. The colour is a little darker, and mine only has the small spots in one area, but I would guess that they are the same.

I lapped the side of mine, and there seems to be less of a problem with the inclusions there, so perhaps I can use it after all :)

The color in the picture is darker than when looking with the naked eye. It is quite a bit whiter. Good luck with the edge.

I have what appears to be such a stone and it's fairly soft, seems to be a fine grit sandstone. The 'grit' is finer than 1000 on mine, but not much, I'd estimate 1500-2000. It also shows a few small pits, where inclusions were I believe. To the best of my knowledge, MY stone is unsuitable for razors. I use it as a pre-sharpening clean up stone, for removing rust and grime from the blade flats of vintage knives. I wouldn't put any edge at all on it, past honing out a significant nick.

Because it doesn't make a slurry (mine doesn't) I've had to struggle to give the rock a job, and the inclusions havn't helped any. There is an east german rock that resembles it, in color and type, but slightly finer and MUCH purer grain and consistency. NO inclusions to mention. It does the jobs well this rock does poorly, even though it's smaller. You might see if you can track one down, they're uncommon but not terribly expensive.

If yours is the same sort of rock as mine, cutting it is risky. sandstone isn't very dense, and it may split.