Unique Natural Stones

[ex1580]

I just got a box in the mail yesterday from France and one of the things in it was a Belgian Violet stone. Obviously it will take some time for me to form an opinion on this stone but the "range" is supposed to be 3-6k depending on how thick your slurry is which is a good finishing range for a variety of kitchen knives (and no burr to worry about hopefully!). I think it's just a pretty Belgian Blue honestly, but I am excited to use this one more. I have used it exactly once, on a razor, and I think it has potential.

[Jeff B]

When sharpening, once you reach an apex a burr starts to form. I don't see how that doesn't happen just because of the stone you are using, it's not logical.

[taz575]

With the slurry on the natural stones, the slurry itself helps remove the burr when sharpening or greatly reduces it.

[ex1580]

When sharpening, once you reach an apex a burr starts to form. I don't see how that doesn't happen just because of the stone you are using, it's not logical.

It's garnets! It is strange, but I read it on the internet so it must be true. Specifically, on the Science of Sharp site, this is why he likes Coticule stones. Cant find a link at the moment.

EDIT: Just FYI, I think it's weird too. Now that I have this Belgian stone I am going to give it a try one of these days. I'll reply back here if there are any remarkable results.

[XexoX]

With the slurry on the natural stones, the slurry itself helps remove the burr when sharpening or greatly reduces it.

Completely unrelated, but you made me think of this.

[ex1580]

When sharpening, once you reach an apex a burr starts to form. I don't see how that doesn't happen just because of the stone you are using, it's not logical.

I've sharpened a few things now with my new Belgian Violet stone and it is pretty interesting to say the least.

In regard to razors, I probably wont use it for razors again (someday when I get a coticule I may change my mind on this). My Shapton Glass 2k, 8k progression leaves a really nice edge and not much work for the finishing stone so I can do a "choose your own adventure" with what finishing stone I pick. The Belgian Violet edge is too big of a jump to the finishing stones I have, I don't care what Science of Sharp says, haha. I would be finishing the razor forever and make mistakes and not good.

As far as kitchen knives, this is where things got interesting. I sharpen my vegetable cleaver (CCK 1303) on everything just to see what happens. In this case I started the Belgian Violet with about as thick of a slurry as I could muster and only gave it a few strops on a clean stone at the end. Under a microscope it looked just like I had used an Arashiyama 1k when I was done. I couldn't tell the difference, which is fine because I like that edge and think it's just about perfect for that knife. BUT, like I said it got interesting because then I did a Wusthof knife which has been pretty burr happy in the past and while this stone didn't completely eliminate the burr (as folklore suggests) there was almost none, which is pretty nice. Not to mention that I took more time to dilute the slurry and under the microscope it looks like a 5k or so finish which might be a little too much for this knife, time will tell.

If this were work I would stick with synthetics because they get it done, but for fun a stone out of the ground is pretty fascinating for some reason.

[Jeff B]

...I did a Wusthof knife which has been pretty burr happy in the past and while this stone didn't completely eliminate the burr (as folklore suggests) there was almost none, which is pretty nice. Not to mention that I took more time to dilute the slurry and under the microscope it looks like a 5k or so ...

Did you check for a burr while you were working the edge? Maybe a burr formed but you worked it long enough to remove a lot of it. This is just my curiosity asking questions.

[ex1580]

That is a possibility. I thought I felt a burr as I was working it but I didn't check with the microscope until I was done on the stone. Next time.

[ex1580]

Did you check for a burr while you were working the edge? Maybe a burr formed but you worked it long enough to remove a lot of it. This is just my curiosity asking questions.

In the name of science I did another one. The knife I sharpened has a history of being very burr happy. With a Shapton stone for example I would need to work at it both on the stones and a strop to get the burr cleaned up. I often microbevel the edge just to save time. It is a stainless knife and we (everyone else in the house mostly) use it for basically anything on the cutting board.

Methods
This time I put permanent marker on the bevel of the knife then made a thick slurry on the stone. I then sharpened the edge in the slurry (edge leading), diluted the slurry and refined the edge with a handful more strokes on each side (still edge leading), cleaned the stone off and stropped it on the stone (edge trailing) with the intent of trying to make a burr, then alternated the strops just to see.

Results
I used the microscope a lot along the way and saw virtually no burr at any point compared to what I see with a synthetic stone (which can create a huge burr easily). When I was purposefully stropping it too much there were some tiny bits of burr visible at 120x but when I switched to alternating strops they went away. This was a significant improvement for sure. The edge turned out about like a carefully done 2k Shapton or maybe a little finer. Neat!

Conclusions
This particular Belgian Violet stone prevented a large burr from forming while sharpening this knife. More data will need to be collected before further conclusions can be made.

One thing is for sure, next time I have a knife with a tricky burr I will pull this stone out and see what happens. Here is a picture of it. It looks very violet colored when it's wet.