Off the Beaten Path - Naturally

[Koop]

How about a thread for natural whetstones that aren't mainstream or collectible? Any interest? I'm finding a lot of possibilities out there - everything from Finland to Indonesia.

I'll start with a few that I'm using.

Three Indonesian stones - medium to fine.

A Japanese stone, but not a collectible - Tsushima ocean stone

A Rozsutec from Slovakia - a very interesting hard, fine sandstone.

I've become fascinated with natural stone sharpening. It's been something that mankind has done since the stone age. I find that synthetic stones are easier and more forgiving, but I take great satisfaction when using natural whetstones and I think I do a better job, since the stones aren't as easy to use as a synthetic and I pay more attention to small details.

I don't know if that makes sense, what I mean is I concentrate more on my technique to get the results with these stones rather than a synthetic progression.

 

[NickMinton]

Curious what your experience has been with the Tsushima.

I’ve been itching to buy one for a while as they’re usually large, cheap and I believe finish out nicely (5-8k)

I understand their probably not great for polishing but it seems you get a lot of bang for your buck

 

[Naftoor]

Away from home, will have to update pics later since it turns out I only have one.

Have a collection of jade stones. Nephrite specifically. Definitely the prettiest rocks I own. Best avoided for sharpening in my book though (unless you want to buy them for the deal of a life time ). I dislike having to dress stones and they need it regularly. Seen people use them more for razors with some being big fans and others being meh. Since they’re so hard I would imagine it might work ok as a base for slurrying and be a pretty backing material.

The ones I was chasing a few years back and still love for stones are what CJA sold as hard whetstones if memory serves (I can’t find the site, has cris finally disappeared? Shame, he did cool looking work when he was consistent). They’re a grayish green rock, very fine, and they don’t have any issues eating metal while also being extremely hard. Pretty much the perfect rock in my experience for anything that isn’t a high carbide supersteel. The rock itself is a bit of a mystery. According to cris, he bought them in giant slabs from a Russian fellow he’d import them from, but as of a couple years ago wasn’t sure if he’d ever be able to provide anymore. The closest thing I’ve found in description would be Songhua stones, which are from a closed Chinese mine that fine, hard stones in a variety of color including grey green and apparently became quite popular in Russian briefly even with the supply issues. I’m a materials engineer though, not a geologist so being able to differentiate rocks is beyond my scope, and I suspect I’d have to damage one of them to actually test the mineral type. This is what they look like wet, they get almost dusty looking when dry.

 

[Koop]

Curious what your experience has been with the Tsushima.

I’ve been itching to buy one for a while as they’re usually large, cheap and I believe finish out nicely (5-8k)

I understand their probably not great for polishing but it seems you get a lot of bang for your buck

My Tsushima is very hard and slow. I need to raise a slurry with either a tomo naguri - again, slow - or a diamond plate (quicker) to get it to cut at a reasonable rate. I use it as finishing stone in my knife progression - more or less a strop. I think it's becoming more useful as it "breaks in."

 

[1315]

Zulu Grey from Africa is a razor rock that I got in a package buy. Est. 12-16K grit...feels more like 20k when running a knife over it, but you can feel refinement on the edge. Very hard and glossy, this one has pyrite/fools gold inclusions in it. Since all my knives are already tuned up, I sometimes run a blade over it for fun because being so fine, it really doesn't remove any metal.