Mystery JNat

[metamorpheus]

I took my first step into the rabbit hole and ordered a mystery stone from an ebay seller in Japan a couple days ago. I'd like to see if anyone can make any guesses about what it is. The seller is pretty sure it was mined in Kyoto, rates the hardness as 6/10, compares the grit to 6000-8000, and thinks that it could be an Akapin. It was 140 with shipping, so I won't be too upset if its not great. On the other hand, I'll be really happy if its a solid JNat finisher for knives for that price. The finish looks a little scratchy on the sellers photo, but I have no idea what kind of progression was used and how attentive they were to converting scratch patterns. I plan on trying a Kohetsu 800, Kohetsu 2000, Naniwa SS5K,to JNat progression on blue #2 at an HRC of 62.

[ChefKnivesToGo]

Nice and muddy. It should produce a nice hazy finish for kitchen knives.

[metamorpheus]

Still waiting on my yaginoshima asagi tomo from Ken, but got this stone in the mail yesterday. This stone is definitely much harder than the seller says. The surface is extremely smooth and my knife glides nicely on just water. The mud being generated was minimal and the stone was real thirsty. It was definitely flipping the edge and making it more toothy.

I finally decided to use my hard belgian blue to raise slurry, which worked, but the stone tends to suck the blue in and get stuck. The stone was much less thirsty in use after raising slurry. Each pass on the stone started raising very light colored slurry that turned to a lighter gray as I worked it down. This stone was very pleasant to use. It's not doing anything fast, but the edge I tested on had already gone from an SS5k up to 1 micron. I worked it for about 45m total.

After a quick strop on leather the knife was push cutting cleanly and cutting through paper towels better than before. On the cutting board it was one of my favorite edges I've ever put on that knife. Smooth clean cuts with tooth to make easy work out of push chopping saggy pepper skins. I can see why people get addicted to Jnats.

[ken123]

Still waiting on my yaginoshima asagi tomo from Ken,....

On it's way ...

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Ken

[ken123]

It looks to be some sort of suita. More likely to get other stone particles stuck in the tiny holes in the stone....

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Ken

[metamorpheus]

It looks to be some sort of suita. More likely to get other stone particles stuck in the tiny holes in the stone....

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Ken

Thanks Ken. Do you say suita because of how thirsty it is for the level of finish? The water is falling into the su? Akapin wouldnt make sense to me for how dense the stone is since that's a more shallow layer. There's definitely no black swarf to be seen here. I saw a tiny bit when using my roommates german and jumping from a 2k, but this is just sharpening the edge. I was waiting on the bamboo 150 before I started doing any cosmetic work/thinning-for a different knife, I'm leaving the Kurosaki as is for now.

[ken123]

I guess suita because of the layers seen along the side of the stone, ignoring the saw cuts. Suita are not necessarily porous - quite often the opposite is true - eg Shinden.
Akapin is often quite soft and not uniformly present in many mines. It îs often an incorrect label. You might simply just call the stone a Honyama, really a general term. To falsely label a stone is a disservice both to your understanding and to others looking for knowledge. Ideally you should have a firm knowledge of the pedigree of your stones.


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Ken