Au naturel - Ink stone (not) mystery stone

Another Ebay mystery. I took a gamble and bought this stone from an Asian antiquities seller. He listed it as an ink stone, but without a well to hold ink......hmmm. The pictures showed what looked like tiny spots or holes, like you see with a suita stones, and it also had some prominent streaks of renge (red pattern). Looks like a sharpening stone to me. Luckily, it works like one too.....

Size 150-100-20 mm, olive green, evergreen, red and white. Slightly translucent!

This is the face that I use. All sides are finished, so no skin.

The spot is a low point. I REALLY didn't want to surface this thing down. It's HARD!

Uses basically no water

SUPER hard! This stone is really beautiful, lots of color and looks 3D. When I received it, it was all polished up with wax, I think. It looks like a gemstone, like a low grade jade or marble. Jadeite? Jasper? Funny to think of me sharpening old rusty tools with a semi-precious gemstone, haha. I tried it out, and the tools had a bad tendency to dig in and gouge and it felt very "grabby" or sticky. The tool would skate, then grab and gouge. Ha! Street fighter stone!

I lapped it with great difficulty using a 1200 DMT diamond stone. It forms a milky white, very thin slurry. Once it was flattened, it worked well. Needs a nagura! Expert stone, way above my pay grade. I'm still learning.

Shall we?

DMT 1200 slurry, sometimes gray, other times white.

T= 1 minute ( after jyunsyou). See the reflection in the steel?

Nice bright mirror!

Forms a creamy slurry, dries slowly and gives a crazy deep finish that just improves the longer that you use it. Surprisingly fast considering how hard it is. I have no idea what this stone is, but it acts like something special. From the photos of the 100's of other stones that I have looked at, it looks a bit like an ozuku asagi, but it is pretty well impossible to tell, especially from photos. I can't speak for everyone, but my photos suck. Ozuku is a mine in japan, asagi is just the color green, I think. It doesn't matter, but I am curious. I would buy another, but I am pretty sure that I couldn't afford it. Definitely a razor stone.

I haven't done it yet, but one of these days, I am going to do isolation tests to more accurately gauge the grit of each of my stones, as a reference piece. It is actually completely irrelevant, but when I started buying stones, I pent a lot of time looking for this type of information. I am currently working my way through Tanaka Kiyoto's  blog. He is a Japanese luthier and writes at great length about tools and sharpening stones. Oh yeah, and crafting guitars. He seems like a REALLY cool guy. I also really wish that I could read kanji. As it is, with Google translate I am only getting about 20% of the content and there is a lot to learn, if you know what to look for. I strive to learn enough to ask the right questions.


---Addendum---
Speaking of asking questions, I am still trying to figure out what this stone is. There are some ink stones without wells, I have found.

So there ya' go.