Your thoughts on my natural waterstone

[Ron Kellison]

The attached pictures are of a natural waterstone that I picked up at a flea market several years ago and I've never gotten around to using. The stone is actually a bit pinker than it shows in the photos. The pictures were taken with a point & shoot camera and I've never had a knack for taking good pictures!

What I'm looking for is any thoughts you might have regarding both the grade and the grit. To my fingers, it feels like it might be somewhere around 4000 grit but I'm no expert on the subject.

Regards,

Ron186935186936186937186938186939

[David Weaver]

Really, no clue what the grit is on it and how fast it cuts, so can't tell you.

I am not a buyer of fine natural waterstones (such a thing is for people who can spend a grand a stone and not worry about whether or not it may only be OK for some tools that they have). I have, however, bought probably 10 natural stones searching for something I think I can say now I never found, so I can offer some amateurish comments that would not be the same as you'd get from Alex Gilmore or So (a seller of fine japanese tools and high quality stones).

Unless the stone has a mine stamp on it or you know the origin, you can't really do anything other than try it. What makes a high class stone to me is:
1) size - #30 and especially #24 sized stones are large for a natural stone, and that one looks to be somewhere in that range.
2) hardness - generally harder stones that are not scratchy are higher class, at least to me
3) grit size - there is some room to move with this classification. The finest stones are very fine, probably finer than nearly all artificial abrasives available. They also cut slowly enough that you have to step up to them with what would otherwise not be a fine finish stone. To me, the stones that work the best are the ones that are a step down from the very finest, because they're practical to use. Those are probably in the 10,000 - 20,000 grit range.
4) uniformity of the grit, lack of scratchiness - uniformity is nice, though different parts of high class stones can have different cutting power, which is probably somewhat related to varying grit. Some of the least desirable stones (hiderayama stone - I have a large one) have a very even grit and not much cutting power for their grit
5) relative cutting power to grit. Fast cutting stones relative to grit size are more desirable

There are appearance based things that make a stone more valuable, but I can't really get into that kind of stuff - it's *really* expensive, and it's bordering on sort of being jewelry value.

Your stone looks like a suita stone with renge from the pictures at a distance. When close up, it looks a little different, but I'm no "renge expert".

My advice would be to see if you like it, and if you do, use it. If you don't have anything about the mine or where it came from, its value is marginalized hugely. I'm sure you got it cheap, though if you got it at a flea.

I have made the broad assumption that this is a japanese stone, I could be WAY off. I have never seen a valuable waterstone of that color that wasn't from japan.

[Ron Kellison]

Thanks for the interesting reply, David!

Suita is a new term to me. I haven't had any luck getting an explanation of the term on the Web so I would appreciate a brief description. I infer that renge means the inclusions or specks of color in the stone. I can add to my initial description of the stone by saying that it is FLAT (!!) in all directions with no pits on the finished surface.

BTW, I paid $3 for this. At the time, I had never even seen a waterstone so I actually spent some time making the decision. I'm now comfortable with the idea that it was a good deal!

Regards,

Ron

[Pam Niedermayer]

As David said, the only thing to do is try it, before and after other stones, and see what it does.

Pam

[Jonathan McCullough]

Charnley Forest?

[Ron Kellison]

As David said, the only thing to do is try it, before and after other stones, and see what it does.

Pam

If I can find the time I'll have a go at it this weekend. My finest stone at the moment is an 8000 grit Norton, occasionally followed by a honing on a .5 micron grit paper on a granite block. It would be interesting to find out how this stone compares to that result.

[Jim Koepke]

When I still lived in California I went in to Hida Tool & Hardware in Berkeley. They had some natural stones on display. Their prices convinced me that my stones would likely always be man made. As I recall, that is where my 4000 King stone was purchased and some of my pull saws.

jtk