Help Identifying a Hone

I'm looking for some help in identifying this hone. It was with some common sharpening stones left by my grandfather, who happened to be a machinist. The stones include several oil stones and Arkansas stones with profiles unique to sharpening tooling edges. I'm not sure what he did with this stone though.

The stone consists of layers with a blue/gray tint. I lapped the top with a DMT D8C and now to the touch its smoother than the Norton 8k. Although the lapped surface is dull in appearance, when wet its as smooth feeling as glass.

http://i625.photobucket.com/albums/t...psb5a7b0d7.jpg

http://i625.photobucket.com/albums/t...ps3f37d85f.jpg

http://i625.photobucket.com/albums/t...pseda40f97.jpg

It's a nice looking stone, but I have no idea what it is.

I have some that look like that but I know yours didn't come from where mine did. I hope yours is quick and smooth.

I may be completely off but that looks like a piece of slate that I have in the garage. That might be a beat up surface plate. Machinists keep precision ground granite surface plates for measuring.

There are many hones from around the world. Some of them looking like yours come from the UK and are varieties of slate. I have one that came over with an Englishman with a bit less blue that weighs in at about 8-10K.
Use a microscope or magnifier over 30X power and see whether you get improvement or degradation of an 8K Norton edge, that will tell you the quality of the stone.
As any one will tell you, the shave quality is the important factor.
~Richard

That might be a granite hone. Its a lot smaller than the granite blocks we used to use in the shop, but the color is not far off. Can be an excellent hone I have heard.

Looks a lot like a few stones I have, still have no idea what they are too although they give a nice smooth edge. All of mine are all natural/rough on the bottom and some of the sides sides though, not cut on all 6 sides like yours.

the stone to the right
Attachment 146836

the middle and the right stone
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they seem to have the same blue look to your stone. im 100% sure mine are not a slate. I just dont know what they are.

I had not considered that it may be a surface plate, it would be a small one for sure.

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Originally Posted by Mechromancer

I may be completely off but that looks like a piece of slate that I have in the garage. That might be a beat up surface plate. Machinists keep precision ground granite surface plates for measuring.

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I found the post (had forgotten I'd already asked about this stone before) from several years ago where it was suggested it may be a Blue Dalmore or possibly a Belgian blue. Anyhow, I took your suggestion - hit a spare razor with the Norton 4k. I then did one side with the 8k and the other with this mystery rock.
The level of polish (as viewed with an el cheapo radio shack 60-100x scope) was almost identical. Another note, the Norton 8k soaks up some water while with the other stone the water just sits on top with no soak. Is that typical of natural stones? Also despite the blue stone feeling glass-smooth it sounds very 'grainy' during use as opposed to the Norton 8k which is almost silent.

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Originally Posted by Geezer

There are many hones from around the world. Some of them looking like yours come from the UK and are varieties of slate. I have one that came over with an Englishman with a bit less blue that weighs in at about 8-10K.
Use a microscope or magnifier over 30X power and see whether you get improvement or degradation of an 8K Norton edge, that will tell you the quality of the stone.
As any one will tell you, the shave quality is the important factor.
~Richard

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I have a few pieces of granite and the grain structure is not at all similar. This hone appears to me to have a very fine grain. Is there similar granite?

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Originally Posted by Magpie

That might be a granite hone. Its a lot smaller than the granite blocks we used to use in the shop, but the color is not far off. Can be an excellent hone I have heard.

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Thanks for the input. I'll post some results one of these days after I finish a razor with this blue stone.

Does your mystery hone have any purple color to it or is it just gray? I bought a stone from a retired machinist having a garage sale years ago. I was very excited since I got it for a good price and it was larger (10x3 but it had a large hole drilled toward each end in order to be screwed down to a work bench. I cut each and off to make an 8x3).

I still have some pics of that stone below. If Methuselah would have spent his entire life honing a razor on the mystery stone I had, he would have cursed Heaven and had a beard down to his toes. I believe mine was slate. It had no cutting ability and I found it worthless as a razor hone. Non-porous and very hard. Kinda cool to look at though.

Attachment 147843Attachment 147844Attachment 147845Attachment 147846

Chrisl

Its green slate

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Originally Posted by eleblu05

Its green slate

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Surely someone could find an actual name for it though, like most natural stones do.

Also, Regarding the stones I posted in my previous post. when I said it's not slate I mean, not your typical slate like welsh slate (that's the only stone I can think of at this point of time that has slate in the name) Is possibly a type of slate although it also surly has a name other then slate.

I'm really keen to find an actual name as well :)

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Originally Posted by ChrisL

Does your mystery hone have any purple color to it or is it just gray? I bought a stone from a retired machinist having a garage sale years ago. I was very excited since I got it for a good price and it was larger (10x3 but it had a large hole drilled toward each end in order to be screwed down to a work bench. I cut each and off to make an 8x3).

I still have some pics of that stone below. If Methuselah would have spent his entire life honing a razor on the mystery stone I had, he would have cursed Heaven and had a beard down to his toes. I believe mine was slate. It had no cutting ability and I found it worthless as a razor hone. Non-porous and very hard. Kinda cool to look at though.


Chrisl

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Have you tried to get some slurry on it?

Hello, I have one , I never get a clue of what kind is.
If you have more info, please post them.

@brighty:

Does the right stone has some glittering particles in it, does the stone glitters when sunlight/light is shining on it ?

Hello, no glittering particles, and when hone the blade is sucked onto the stone, Sham sold a similar one , he said is Cutlers Green,and if you look at Olivia site, is look like your stone, so you may be a lucky owner of a Cutlers Green

I do believe Olivia's CG was already discussed and more or less agreed is not CG. Please correct me if I I am wrong.
The only descriptions of CG I got hold were citing green and blue hone which is colourwise different from right hone.

When comparing grit, first hone the razor with a known grit, e.g. 8K. Then hone just the Toe half of the razor with the unknown natural grit.

Now you can easily compare the stria patterns from each stone under magnification, side by side.

On many of the naturals I have rescued in the wild/collect I don’t know what they are. And it really does not matter, I just need to know where in the progression they fall.

What I am looking for is a finisher. Can it improve an 8k or 12K edge?