Help Identifying this JNAT

[Nino-chan]

Hi guys I need a little help identifying this stone I have
the dimensions are 16cmx6cmx1.7cm


the flat side of the stone has a pretty smooth finish.
when sharpening it feels smooth and sound similar to my Shapton glass 2000 grit

side view


when i look closely theres a little yellow colouration on the stone on the top left corner


the colour of the slurry


it doesnt give a mirror polish and the edge again looks like a similar finish to my Shapton glass 2000


the stone feels hard and smooth like a finishing stone but it finishes like a 2000grit for me.

what are your thoughts? any ideas on what type of stone/ grit this is?

cheers

 

[GBT-Splint]

Whoo good luck with that, I'm curious to see where this is going to go.
I've heard from Maksim JNS that only a few specialist in japan could identify a stone and that can only be done by testing the particular stone.

But maybe someone enlightened here can help you define at least the strata or something else.

 

[Nino-chan]

Yes I hope someone more knowledgeable than me can help.

this info is from JNS

Uchigomori
This stone is used for cloudy finish for sword as finger stones or bench stone
Uchigomori come only from Ohira and Mizukihara mine, and not other ! If you hear That it is Nakayama or Shoubudani etc. Uchigomori it will be fake, as many try to fake this stone !
Those stones are only between 3000 and 5000 grit, not more. They are known for their super soft particles that will not scratch Tamahagane steel. They are not as fine as some think, Tamahagane is quite soft steel and it can not handle to fine polish, it will also get scratched when harder stones are used. Uchigumori are also very slow stones, they are not used for sharpening, as many think, they are only used for polishing and to bring contrast between hardened steel clouds and the hamon.


I am getting a cloudy finish on it and it could be in the 3000 grit range?

 

[Olsen]

Some Jnats are quite characteristic and are IMLE (In My Limited Experience) relatively easy to distinguish : Ohira Suita, ohira uchigomori, okudo suita, tushima nagura, aizu, binsui, maybe hideriyama, but naaaa. And that is by their looks alone. I am not sure finish says a lot regarding which stone you have got.... of course if it feels like your 3000 grit synthetic or you can create a palpable burr it is probably not your average nakayama finisher

 

[GBT-Splint]

Yes I hope someone more knowledgeable than me can help.

this info is from JNS

Uchigomori
This stone is used for cloudy finish for sword as finger stones or bench stone
Uchigomori come only from Ohira and Mizukihara mine, and not other ! If you hear That it is Nakayama or Shoubudani etc. Uchigomori it will be fake, as many try to fake this stone !
Those stones are only between 3000 and 5000 grit, not more. They are known for their super soft particles that will not scratch Tamahagane steel. They are not as fine as some think, Tamahagane is quite soft steel and it can not handle to fine polish, it will also get scratched when harder stones are used. Uchigumori are also very slow stones, they are not used for sharpening, as many think, they are only used for polishing and to bring contrast between hardened steel clouds and the hamon.


I am getting a cloudy finish on it and it could be in the 3000 grit range?

I use uchigomori fingerstones and the slurry looks like that that's all I can say but it doesn't mean anything
But uchigomori are not meant to sharpen just to polish I believe.

 

[GBT-Splint]

Some Jnats are quite characteristic and are IMLE (In My Limited Experience) relatively easy to distinguish : Ohira Suita, ohira uchigomori, okudo suita, tushima nagura, aizu, binsui, maybe hideriyama, but naaaa. And that is by their looks alone. I am not sure finish says a lot regarding which stone you have got.... of course if it feels like your 3000 grit synthetic or you can create a palpable burr it is probably not your average nakayama finisher

I believe this is not true. Two stones from same quarry and same strata can look drastically different.

 

[inferno]

Yes I hope someone more knowledgeable than me can help.

this info is from JNS

Uchigomori
This stone is used for cloudy finish for sword as finger stones or bench stone
Uchigomori come only from Ohira and Mizukihara mine, and not other ! If you hear That it is Nakayama or Shoubudani etc. Uchigomori it will be fake, as many try to fake this stone !
Those stones are only between 3000 and 5000 grit, not more. They are known for their super soft particles that will not scratch Tamahagane steel. They are not as fine as some think, Tamahagane is quite soft steel and it can not handle to fine polish, it will also get scratched when harder stones are used. Uchigumori are also very slow stones, they are not used for sharpening, as many think, they are only used for polishing and to bring contrast between hardened steel clouds and the hamon.


I am getting a cloudy finish on it and it could be in the 3000 grit range?

it doesn't have to be an uchigumori. also uchis can vary a lot between different stones.
i've seen many uchis have a rough chiseled surface. its very distinct.

my uchi seems quite fast to be honest. it removes metal in like 2 strokes. and i can definitely sharpen on it. its the most creamy and nice stone i have every tried. just the right amount of resistance.

the surface it leaves is a haze, a very fine haze. but i guess they are all different.
it also changes color from blue/gray when dry to dark moss green when wet.

finish is about 3-4k for mine.

imo if you like the stone, keep it. use it. it doesn't matter what it is. it could be a polished turd. if its good its good no matter what its called.

 

[Nino-chan]

Im going to do a bit of digging about... excuse the pun... and see what characterists best match my stone. anyone got any good reference I could check out?

 

[GBT-Splint]

it doesn't have to be an uchigumori. also uchis can vary a lot between different stones.
i've seen many uchis have a rough chiseled surface. its very distinct.

my uchi seems quite fast to be honest. it removes metal in like 2 strokes. and i can definitely sharpen on it. its the most creamy and nice stone i have every tried. just the right amount of resistance.

the surface it leaves is a haze, a very fine haze. but i guess they are all different.
it also changes color from blue/gray when dry to dark moss green when wet.

finish is about 3-4k for mine.

Good to know, I took the word of JNS wiki for a fact but Jnats seems to be a world full of surprises

 

[Nino-chan]

it doesn't have to be an uchigumori. also uchis can vary a lot between different stones.
i've seen many uchis have a rough chiseled surface. its very distinct.

my uchi seems quite fast to be honest. it removes metal in like 2 strokes. and i can definitely sharpen on it. its the most creamy and nice stone i have every tried. just the right amount of resistance.

the surface it leaves is a haze, a very fine haze. but i guess they are all different.
it also changes color from blue/gray when dry to dark moss green when wet.

finish is about 3-4k for mine.

imo if you like the stone, keep it. use it. it doesn't matter what it is. it could be a polished turd. if its good its good no matter what its called.

oh definitely ill be keeping it but idealy would like to know the history behind it

 

[inferno]

Good to know, I took the word of JNS wiki for a fact but Jnats seems to be a world full of surprises

its a very deep rabbit hole. and it can get very expensive very fast. all the stones are different. even from the same mine/strata/appearance they can vary a lot. and also one stone that you think its good another person may dislike for the exact same reason.
i think the best thing to do is test these in person. but its not really doable most of the time.

i'm not really into jnats so i only have my 1 uchi (it was 200€ or so). and i'm happy with that. its very good for kasumi finishes. and good for edges on low alloyed carbon steel.

but yeah if i have like 10 grand to blow on fun things i would definitely get 1-2 more to try out.

 

[inferno]

oh definitely ill be keeping it but idealy would like to know the history behind it

even if someone tells you its a x from strata y or mine z. you will never truly know. even if the stones are stamped you can't really be certain of where it came from and what it is.
its just a stamp on a rock.

if its good its good. thats it. and if its not, it doesn't really matter anyway.

 

[inferno]

here is my ohira uchigumori supposedly.

dry/wet, it looks greener in reality when wet.

1min on a stainless edge results in absolutely nothing

10 seconds on carbon/iron and the whole stones turns black with steel. black is the only color of the slurry from this one. and orange rust of course

result, this is what they do. a fine haze

 

[GBT-Splint]

it's a really good looking stone especially wet ! have you any idea how this golden pattern is called ?

 

[inferno]

i dont remember. but many of the uchis have this brown/gold pattern. its extra visible when wet.