# natural stones



## millionsknives (Apr 25, 2014)

Oh no! My first JNAT. I hear it is a slippery slope from here into the abyss

Okudono Suita Koppa, 136x76x29mm, Med-Hard





  








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millionsknives


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Jan 20, 2017








I won't have time to play with it until sunday but as I understand it is a splash and go medium hard, fine grit stone. I intend to use it as a finisher. Next I'll get a medium grit stone and go all natural, just not sure which one yet


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## foody518 (Aug 6, 2015)

Thanks for grabbing that so I didn't end up doing so! Good starting choice. Start a bit behind the edge if you can to kick up some initial swarf.
It has been a very slippery slope for me O.O

This is a medium fine natural I got recently - Aizu. 




  








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foody518


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Jan 21, 2017







I got it to bridge between the 1-2k grit mediums to the 6-8k+ fine to very fine naturals that sometimes don't really cut fast enough take out the 1-2k scratches (you could play around with making slurries with coarser grits to enhance cutting speed) . Another one that might do that bridging job is Khao Men - a Thai natural stone.


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## rick alan (Nov 15, 2012)

Where did you get that sink bridge?


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## millionsknives (Apr 25, 2014)

This one https://www.japaneseknifeimports.com/collections/sharpening-accessories/products/stone-holder-1


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## foody518 (Aug 6, 2015)

Have you had a chance to use this yet? Curious to know your thoughts!


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## millionsknives (Apr 25, 2014)

Not yet!  I have too many side jobs.


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## foody518 (Aug 6, 2015)

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foody518


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Feb 15, 2017







Two medium bricks I have - Thai White and Orange 'Binsui' stones. I call them Rings of Saturn and Orange Cream Soda XD. I've been using them as finishers for other people's cheap stainless knives recently (among other uses) :O

The white doesn't cut fast at all on its own, doesn't shed much abrasive but can be rubbed against a tomo nagura or other naguras/stones to generate some slurry for the cutting action. I'd guess the grit range can be worked to mid to high 1k range. Feels very firm. Surface has a tendency to load up or glaze over which adds another dimension to how this can be used (I've loaded it up with aoto slurry for polishing work). I can only describe the edge it can impart as surprisingly crisp feeling (whatever that means in my head) relative to its scratch pattern and perceived grit range and what results I usually get from medium grit stones. Will sometimes also use this during whimsical natural progressions.

The orange is coarser, more porous (many visible voids). Cuts faster on its own but still not really comparable to decent cutting 1k synths. I've been doing a better job generating smaller burrs and working down burrs with these guys.
Both are splash and go and don't feel right when used with too much water (have enough to wet but not puddle on the surface). Slurry and cutting action tends to feel grainy or sandy. Both will do better to be preceded by a fast cutting coarse or medium synthetic stone that can establish a defined bevel IME (use more for refinement than bevel setting)


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## millionsknives (Apr 25, 2014)

@foody518 I used this for the first time today in a long overdue sharpening session. That tells you how many knives I have that I just rotate them out!

It's slick like every synthetic finisher I've used. Definitely not a muddy stone at all. I like it so far, time will tell if the edge lasts longer. The theory is you get particles of varying sizes coming out of a natural stone, so the microscopic 'teeth' it leaves are more randomly sized which is good for cutting at that level but also it should last longer.


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## foody518 (Aug 6, 2015)

Heyyyy cool! Glad to see you finally got around to playing with it!
Used it on any wide beveled knives? I like the feeling of some of those harder stones with some sort of slurry worked up on them


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## rick alan (Nov 15, 2012)

MillionsKnives said:


> @foody518 I used this for the first time today in a long overdue sharpening session. That tells you how many knives I have that I just rotate them out!
> 
> It's slick like every synthetic finisher I've used. Definitely not a muddy stone at all. I like it so far, time will tell if the edge lasts longer. The theory is you get particles of varying sizes coming out of a natural stone, so the microscopic 'teeth' it leaves are more randomly sized which is good for cutting at that level but also it should last longer.


Just technically speaking:

Yes the specified grit size of synthetics is actually an "averaged" particle size, but less randomized than naturals. The so-called synthetic-naturals use an intentionally more "randomized" particle size. It is likely a non-linear averaging also, like used in mixing agglomerates for concrete and polymer-based structurals.

I have seen Shapton claims for their stones using a more singularly consistent/less random-averaged particle size. Likely the way they get the aggressive cutting with such a hard stone, and why their higher grits get so expensive, the classifying/sifting process is more time-intensive the higher you go in grit size.

But the reason diamond powders are less expensive for most of the higher grit sizes is because the manufacturing process is very random and fewer large size particles get produced.


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## kokopuffs (Aug 4, 2000)

The one on the left side of the photo resembles my medium arkansas stone.


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## rick alan (Nov 15, 2012)

Some Fine Translucent Arks, my preferred Ark, do look similar, often tan or beige to slightly orange, with some striping.


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## foody518 (Aug 6, 2015)

Rick, I feel like I have seen similar claims from Naniwa for their Chosera/Professional line, about closer grit tolerance. Would explain the freaky prices as you get to their finer stones

Here's an info page on the Thai Binsui. At the very least, the abrasive type is different from the novaculite in natural Arkansas stones. http://naturalwhetstone.org/index.php?title=Mountain_Water_Stone_-_Thai_Binsui


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