Bevel Tip and Magnification

[Woodash]

Steve,

Curious what microscope you use.

Thanks. George

George -
I think this is the exact same one I have, probably purchased from the same vendor: http://cgi.ebay.com/1-3MP-LED-USB-D...29? pt=LH_DefaultDomain_0&hash=item4153c2a075

It's cheap (~$30.00), the vendor I believe is reliable (I had no problem, fast ship). The scope has 2 ranges: 10-65x and ~230x. It's not fancy, but for what I like to look at, it's fine.

 

[wdwrx]

ah ha! But will it work on a Mac?

I've been toying with the idea if picking up a USB camera attachment for my microscope, as it's a good quality 'scope, and it's got a third tube that can fit another ocular lens. Not to chase ghosts, but to more reliably track changes in edge development.... I've got CRS, it seems. Barring that, I've been eyeballing the Veho 400. Not sure how much money I want to spend on this aspect of honing though.

 

[Woodash]

ah ha! But will it work on a Mac?

I've been toying with the idea if picking up a USB camera attachment for my microscope, as it's a good quality 'scope, and it's got a third tube that can fit another ocular lens. Not to chase ghosts, but to more reliably track changes in edge development.... I've got CRS, it seems. Barring that, I've been eyeballing the Veho 400. Not sure how much money I want to spend on this aspect of honing though.

If your Mac can read a standard thumbdrive USB, I see no reason why this camera wouldn't work. Mine is very similar to the Veho, but I think the Veho goes to 400x. You should know, however, that for US$30, it's still pretty much a 'toy' with different focal length, etc. than you might be expecting for use in your scope.

 

[rayman]

Steve all I can do is repeat what I have said all along "if we look at our edges with enough magnification, we would throw them all away!"...lol

Regards
Ralfson (Dr)

This is great advice and I have to agree with Ralfy. I have a Veho USB microscope that I literally never use. What I do use is a 60x - 100x hand held from Radio Shack.

Eventually you will discover that the only thing that counts, when finishing the honing process, is the edge. The part you see, the bevel, could have gouges in it or even holes drilled through it or naked women tattooed in it like Ralfy does to his and it wouldn't matter. As long as the edge is perfectly smooth and sharp, like your photos show, that is all that counts. This is not rocket science.

Ray

 

[Woodash]

Steve all I can do is repeat what I have said all along "if we look at our edges with enough magnification, we would throw them all away!"...lol

Regards
Ralfson (Dr)

This is great advice and I have to agree with Ralfy. I have a Veho USB microscope that I literally never use. What I do use is a 60x - 100x hand held from Radio Shack.

Eventually you will discover that the only thing that counts, when finishing the honing process, is the edge. The part you see, the bevel, could have gouges in it or even holes drilled through it or naked women tattooed in it like Ralfy does to his and it wouldn't matter. As long as the edge is perfectly smooth and sharp, like your photos show, that is all that counts. This is not rocket science.

Ray

Ray - I agree with you. And actually, I think I already have discovered that the edge is the only thing that counts. I have several interests with the scope. I mainly use other methods to probe the edge, but after I'm done honing, I might check for microchips. If I can't see them at 230x, I pretty much don't care about them. I find that useful. But, like I said, there is a lot of information that I'm interested in beyond just evaluating the edge.

 

[vgeorge]

It is wonderful that you can take such good pictures with your microscope. I have a Smithsonian (QX5 by "Digital Blue", if that means anything). I have never managed to get as good pictures as yours. In my pictures, the contrast is all messed up, and the big light really creates too many reflections. I probably should take it out of its stand and try some experiments. I think we are all very visual people looking for cues as we hone. The thinness/fineness of the edge makes it very frustrating.

 

[Bart]

I highly doubt those are garnets. For starters the size doesn't fit. If they were that big, at 7 Mohs hardness, they would eat big chips out of the edge. Furthermore, I have been poking at very similar red dots in BBW's, that can also be found in many Coticules, but then they're white. The dots appeared to be soft enough to be scratched with a needle. And they were impossible to work out. (I was trying to isolate one, because I too thought they were garnets)

Then I read in the paper of Ulrich Kramm:

The coticules of types 1, 2, and 3 can contain yellow to white kaolinite spots in their spessartine-rich layer units. The size of these spots varies from 0.1 to 1 mm.
They are similar to the kaolinitic flakes of the neighboring shales (Theunissen,1971; Kramm, 1973). In the adjacent rocks they are concentrated in a thin strata overlying the coticules. The thickness of this zone amounts to some centimeters.

Kaolinite can have such colors, possibly reddish in the BBW parts, (I guess caused by the presence of Fe) and it is at Mohs 2.5 consistent, with my estimation of the softness of the spots I observed.

I think we're seeing the garnets as much smaller entities that reflect the light, some are large enough to show their roundish shape.

Kind regards,
Bart.

 

[Woodash]

I highly doubt those are garnets. For starters the size doesn't fit. If they were that big, at 7 Mohs hardness, they would eat big chips out of the edge. Furthermore, I have been poking at very similar red dots in BBW's, that can also be found in many Coticules, but then they're white. The dots appeared to be soft enough to be scratched with a needle. And they were impossible to work out. (I was trying to isolate one, because I too thought they were garnets)

Kaolinite can have such colors, possibly reddish in the BBW parts, (I guess caused by the presence of Fe) and it is at Mohs 2.5 consistent, with my estimation of the softness of the spots I observed.

Hard to say, Bart – you may well be right. But the problem is that if they’re not garnets, then they have to be accounted for in some way and that’s not easily done. The bulk mineralogy of this BBW sample is quartz, mica, chlorite, hematite, kaolinite, rutile, with a few accessory minerals, and these phases just won’t give you the large, well-formed, faceted crystals that are shown. Kaolinite does not have this morphology at all and it simply cannot take on anything close to this red color because - with all due respect to Mr. Kramm - it cannot accommodate enough Fe in the structure. I could think of a few other possibilities to explain all this, but they seem really unlikely.

Again, while I know the bulk mineralogy of this stone, I can only speculate as to the nature of specific single grains without additional work. But I personally don’t find it surprising that there may be a few coarse-grained garnets with well-defined crystal faces present.

If this turns out to be of interest in the future, petrography and density separations in heavy liquids would provide a lot of info.

Rgds,
Steve

 

[Smythe]

What if they are groups of individual garnets, that are packed so close together, they appear as one.

Edit:
... maybe would explain why the quartz "running from NE to SW" cross cuts the garnet (possibly through-cut the group of garnets).

 

[Bart]

If these were garnets, they would not be flush with the surface. We're clearly looking at a mineral that's soft enough to be abraded in plane with the surface. Garnets would protured the surface and ruin the edge at that size.

Kind regards,
Bart.

 

[Woodash]

What if they are groups of individual garnets, that are packed so close together, they appear as one.

Edit:
... maybe would explain why the quartz "running from NE to SW" cross cuts the garnet (possibly through-cut the group of garnets).

You might be right, Smythe. But the thing that gets me - really one of the main things that flips me out about this whole thing - is that these grains (whether conglomerates or not) really have the morphology like the garnets. That quartz vein does look younger than these red grains. Whether they exploited a crack in the grain as you said, or cut through a group of smaller grains - I don't know.

If these were garnets, they would not be flush with the surface. We're clearly looking at a mineral that's soft enough to be abraded in plane with the surface. Garnets would protured the surface and ruin the edge at that size.

Kind regards,
Bart.

Like I said Bart, you may be right, but either way, I believe that all this is only speculation at this point. As long as we're speculating, I would go further and say that these grains do not necessarily look in plain with the surface to me. There appears to be a weathering rind/alteration around the grains, removal of some material from around the grains. Additionally, the 3% garnet content measured in this sample might possibly be too low to ruin and edge, especially if not much garnet was released to slurry (I don't know...), but it could possibly explain why some BBW are much less abrasive than others.

Again, I think it's very difficult to say one way or another with this imaging. You may well be right. I don't think we're going know for sure until a couple of thin sections are analyzed by a petrographer or until some density separations, or something along those lines is done.

 

[DJKELLY]

 

[Bart]

I'm telling you, speculation or not, I can scratch spots on my BBW's that look completely similar to your picture, with the end of a paper clip.

I don't claim to understand it all, but I'm doing my best.

Here's a SEM images of a piece of Kaolinite, charged with oxides of FE.

That doesn't look unfamiliar to me, although the size of these structures is smaller.

By the way, Kramm's analytic methods seem pretty serious to me, beyond speculation:

Chemical rock analyses were made either by wet chemical methods (Na, K, Mg, P, Fe 2+) after dissolving
the samples in HF-HC104 mixtures, or by X-ray fluorescence of Li2B407 fluxes using internal
and external standards (Si, Ti, A1, Fe, Ca, Mn). The determination of Fe 2+ was carried out according
to the vanadate method (Peters, 1968), using a closed reaction vessel thus preventing the oxidation
of the sample during fusion. Water content as H20 and H20 + was titrated using Karl Fischer's
reagent (Lindner and Rudert, 1969).
Chemical compositions of the minerals were determined using an ARL-EMX electron probe
microanalyzer (operating conditions: 15 kV, 0.07 ~tA beam current, beam current-time integration).
Natural standards served for calibration (Garnet standards: 12442, 7SP-1AL-1GR-1PY). Corrections
for mass absorption and secondary fluorescence were done with special regard to H20 contents using
the correction factors of Albee and Ray (1970). The water content of chloritoid was presumed to be
constant (theoretical H2O content of Fe-chloritoid), and H20 contents of chlorites were estimated
from their Mg/Fe ratio using a nomogram based on data of Deer et al. (1963). Since there is no zoning
in the minerals investigated, the chemical analyses given in Tables 3-5 are averages of 20 one-point
measurements.
The quantitative mineral composition of the rocks was investigated by X-ray diffraction methods.
Kaolinites were determined by the d-spacings of their basal reflections after having been submitted
to an intercalation reaction to form hydrazine kaolinite (Weiss et al., 1963).

But I'm not Kramm, and unfortunately I can't ask him to chime in here to shed some light.

Additionally, the 3% garnet content measured in this sample might possibly be too low to ruin and edge, especially if not much garnet was released to slurry (I don't know...), but it could possibly explain why some BBW are much less abrasive than others.

There is no doubt, that if as much as one single garnet of that size would be included in a stone's surface, you'd hear a nice "click" each time a blade passes over, causing a missing chip in the edge.

These phases just won’t give you the large, well-formed, faceted crystals that are shown. Kaolinite does not have this morphology at all and it simply cannot take on anything close to this red color because - with all due respect to Mr. Kramm - it cannot accommodate enough Fe in the structure.

[img=600]
http://t3.gstatic.com/images?q=tbn:cj4jv3dQ437ErM:http://search.datapages.com/data/sepm/journals/v38-41/data/041/041004/figs/1003_f13.jpg&t=1[/img]
And here's a picture of red Kaolinite:

And for kicks, a shaving soap :

Ingredients: Sodium Lardate, Sodium Olivate, Sodium Cocoate, Sodium Castorate, Sodium Soyate, Sodium Stearate, Glycerin, Parfum, Red Australian Kaolin Clay

Kind regards,
Bart.

 

[Woodash]

‘The gentleman doth protest too much, methinks’. This discussion seems to be getting bizarre Bart, but I feel like I have little choice but to respond.

I'm telling you, speculation or not, I can scratch spots on my BBW's that look completely similar to your picture, with the end of a paper clip.

And I would say the same thing that I’ve told you before: I don’t have any problem with that, but that doesn’t make these materials kaolinite as you suggest.

Here's a SEM images of a piece of Kaolinite, charged with oxides of FE.

That doesn't look unfamiliar to me, although the size of these structures is smaller.

First, we need to distinguish between a mineral ‘charged’ with (red) oxides and an actual red mineral. Second, yes – the size of kaolinites is very small, with a few exceptions. That should tell you something right there. Additionally, the world is filled with hexagonal symmetry everywhere you look. Neither your SEM pics of hexagonal kaolinite, nor the cubic morphology of garnet in the following image for that matter sways me much in this discussion. Symmetry has to be taken in context with other things, and in this case, both images mean almost nothing to me.

By the way, Kramm's analytic methods seem pretty serious to me, beyond speculation:
Quote:
"Chemical rock analyses were made either by wet chemical methods (Na, K, Mg, P, Fe 2+) after dissolving
the samples in HF-HC104 mixtures, or by X-ray fluorescence of Li2B407 fluxes using internal
and external standards (Si, Ti, A1, Fe, Ca, Mn)….snip."

A moment ago you said that you ‘don't claim to understand it all, but I'm doing my best,’ (^ above) but now you conclude that ‘his methods are pretty serious and beyond speculation’. I’m not sure that I understand this distinction….

But I'm not Kramm, and unfortunately I can't ask him to chime in here to shed some light.

Where would you like to shed some light? I’ve used all of these methods and I’ve taught people how to do most of them for years. I’d be happy to discuss any of this with you if you like. What would you like to know?

Fact is that no one is questioning Kramm’s methods. They’re basic characterization techniques for the mineral sciences. He wrote an excellent paper that I really enjoyed reading. I’ll gratefully accept the information he provides, but I will certainly question some of his interpretations if and when I think there is a legitimate basis to do so. It’s not the bible (so to speak), nor should everything be taken as gospel just because it’s in print (or on the interwebs these days…). That would be silly.

He says nothing about there being any appreciable Fe content in kaolinite. But if I missed something in reading his paper and he did mention that, then he’s either wrong, or he has mistaken something else for kaolinite. I will repeat what I said in a previous post: it is not possible to have more than only very minor (or trace) amounts of Fe in the kaolinite structure. It is the Fe in the structure that makes a mineral red, and kaolinite simply is not a red mineral because it has very low Fe content. To identify these red grains in my image as kaolinite based on red color/Fe content and ambiguous morphology is a creative stretch, in my opinion. I should probably just stop right there and move along…..but I can't, yet. :

What is possible is for any mineral to be coated by other minerals. Minerals in highly weathered landscapes are often coated with extremely finely-divided Fe-oxides, for example. That’s in fact why many subsoils around the world are red (or yellow). It’s because it is often so finely-divided that Fe-oxide (hematite) makes a good finishing paste.

The ‘Red Australian Kaolinite Clay’ that you cite is commonly used for cosmetics and is red only because it is mined in the ancient, lateritic terrain of Western Australia where essentially everything in the weathering environment – soils, surficial deposits, etc. - is dominated by red or yellow Fe-oxide coatings. From one of the commercial websites: ‘cosmetic grade red kaolinite is made up of naturally occuring dolomite, silica, ferric oxide and other mineral oxides.’ It may vary in composition from place to place, but the point is that i) it is not typically pure phase kaolinite, and ii) more importantly, it is red because all the mineral components are coated by Fe-oxides.

Kaolinite isn’t inherently red and neither is quartz, nor mica, nor red sandstone, etc. for that matter. So, there is a huge difference between red minerals, and minerals that happen to be coated red – or are ‘charged’ with Fe oxides as you say.

The significance is this: if the red minerals in my image were red because of Fe-oxide coatings, then essentially all minerals in the image would be coated red like your mixed-mineral ‘red kaolinites’ which they clearly are not. I believe that the red minerals in my image are actual ‘red’ minerals – like ruby or ‘rose quartz’ (or even uh...garnets) - because they have Fe in their structures and are therefore inherently red. I have some other thoughts as to what they might be, but I will restrict my comments here to the kaolinite discussion.

As I’ve said many times before in this thread, I’m willing to stipulate that the red grains in my image may not be garnets. I don't know why, but that message seems to have become lost. I can also speculate that they might be garnets based on color/morphology, etc., but I also know the limits of this information and I’m willing to consider other, plausible options. I’m glad that you are so confident as to conclude that these materials are in fact kaolinite. I would suggest, however – just for kicks – that before you post a lot of pics of marketing material from Australian mining and cosmetic companies, you gather some better evidence that is more relevant to this situation.

This discussion is getting pretty sloppy and I’m sure of little interest to most folks around here. If you’d like to continue with all this, we can take it offline or continue here as you wish.

Regards,
Steve

 

[wdwrx]

I am absolutely fascinated, so I sincerely hope that this discussion can be continued here.:thumbup:

 

[Bart]

Steve,

First of all, there is no need to become defensive.
You are a mineralogist or a geologist, or both. So is Ulrich Kramm. I am not, and I only partially understand Kramm's paper and what you are saying. I realize very well that in order to understand more, I'd first need to get a degree in basic mineralogy. Which is not something I can catch up with by reading a book overnight. So, I'm out of your league for having this discussion.

But still, being the asshole that I am, I could not else but to express my honest doubt that these spots are garnets. I've made my point: at the Mohs hardness of spessartine garnet, such large grains should:
1. damage the edge of a razor, even if only one were present
2. not be scratchable with a needle as if they were of chalk-like hardness.
In my crude, non-educated logic that does not just render your claim ("look here, garnets") to be a speculation. It renders it plain mistaken.

If you search deep enough into my old posts, you'll find a statement of mine in which I made the same error. Only later I realized that it didn't make sense. I had to dig out a coarse grain out of the surface of an otherwise fine Coticule. That grain was eating a chip out of a razors edge, every time the blade passed over it. That particular Coticule had -as many of them do- also these small pale spots, that I'd always thought to be garnets. But lo and behold, that grain I dug out (it had a translucent brown hue, almost like brown glass) wasn't any bigger than those white spots. White spots? But we're talking about red spots, right?
I present an image of a piece of Coticule that has these spots. And a magnified detail.
[img=800]http://www.coticule.be/tl_files/barts_pics/petas2.jpg[/img]

Note how the white spots turn red when they enter the BBW rock. I speculate, that's where they've become contaminated (or charged, or whatever the proper mineralogical term is) with iron oxide.

I tried digging one out, in the same fashion as I did with that foreign grain, working with a needle under the stereoscope. But whatever I tried, they pulverized during my efforts. The spots seemed as soft, if not softer, than the surrounding material.

Months later, I finally got a hold on Kramm's paper, a document that formerly was only available for paid download. I read this fragment:

The Coticules of types 1, 2, and 3 can contain yellow to white kaolinite spots in their spessartine-rich layer units. The size of these spots varies from 0.1 to 1 mm. They are similar to the kaolinitic flakes of the neighboring shales (Theunissen, 1971; Kramm, 1973). In the adjacent rocks they are concentrated in a thin strata overlying the Coticules. The thickness of this zone amounts to some centimeters. In contrast to the dark gray to violet shales, the color of this zone is light gray to reddish.

To me, that sounds very much like the spots in the picture. All the more, because I am not aware of any other spots that occur frequently in Coticules and could conform with what Kramm describes.

Now. If I have to choose whether I'm following, in this particular case:
A. Kramm who makes documented claims (Kramm fully disclosed his research methods: I quoted them in my previous post) about an object he studied extensively in a paper that was submitted and accepted as a scientific publication, and B. Feldman, who teaches mineralogy and claimed on an Internet forum that this spots upon his first sight are spessartine garnets, I am going to follow Kramm. If you take that as a lack of respect, I can only regret it.

For me, a discussion is never about my or anyone else's reputation, hence I don't have any need for a conversation behind closed curtains. I've already changed my mind once, about these mysterious little spots, and I will happily do so again. But I'm not one to accept "because I said so" as valuable evidence in a discussion. I'll even admit that statements of such nature have slightly the opposite effect on my leaning in a discussion.

I have, with my limited understanding of the subject, researched a number of resources, and applied logic combining what I read with a few personal observations. That's how I came to post that these spots might be of Kaolinitic nature.

You said: they don't have the correct shape. I showed a picture from a scientific paper of Kaolinite samples showing spots with exactly that shape. I don't understand half of what that paper says, so maybe I'm wrong.

You said they can't have that color. Wikipedia says Koalinite can have a pink or red color when doted with Fe, and I have shown a picture of Kaolin with almost exactly the color of the spots in your picture.

Am I jumping conclusions? Possibly, but without documented argumentation, I'm not easily convinced that Kramm was wrong. With me "reading him as gospel", that has little to do. It's odd that you suspect me of that.


Kind regards,
Bart.

 

[shaved]

Please don't discontinue the interesting discussion. I'd just like to add some experience I had with these things.

After lapping a new stone up to 1000 grid with w/d paper I found that it got much coarser than before lapping and that continuing it wouldn't improve anything.

Looking with a loupe showed irregular yellow 'dots' and structures with seemed to be grooves. My theory was that the dots got ripped out of the stone during lapping and cut the grooves before breaking down. These grooves seem to show up on pictures of other stones too.

The dots could be felt with the fingertips. Similar to braille.

Of course the stone was in no shape for honing in that condition. I've used a stiff 3/8 razor and pressure to flatten it. That took it's time but worked (and the razor was sharper than ever afterwards).

The picture is not that good. Some of the dots seem to be cut.

Did I mention that I hate these things? A name would be nice 'cause I'd know whom to curse.

 

[Woodash]

Please don't discontinue the interesting discussion. I'd just like to add some experience I had with these things.

Not to worry. I'm busy preparing a response to Bart's last post, but it is not yet antagonistic enough. I'll keep working on it. :

 

[Bart]

Of course the stone was in no shape for honing in that condition.

I'm not so sure about that. I've honed on Coticules that came fresh of a 120 grit diamond lapping plate (a DMT XX). While this completely gives the stone a different feedback when compared to it's natural smoothness (= the surface that develops over use), the edges are just fine.

Here's the magnified picture of a La Nouvelle Veine's "natural" surface. (80X, shearing light source)

If a Coticule was a monolithic in the sense that it would use its surface roughness to abrade steel, it would be far to coarse for putting a final edge on razors. I have read that the Spyderco UF is a (manmade) hone that works according to that principle: a mono-hardness (ceramic) block that relies on its surface relief for fine abrasion.
But Coticules only abrade with the exposed particles that are of sufficient hardness to abrade. It is likely that other particles are at the same time offering a kind of buffing action. I believe natural hones are very complex in the way they work steel.

Kind regards,
Bart.

I'm busy preparing a response to Bart's last post, but it is not yet antagonistic enough. I'll keep working on it. :

Looking forward to that.

 

[Bart]

Since I've got a week off... again... and all my razors are screamin' sharp, maybe I'l dink around with the 'scope and see if i can' isolate a garnet.

Please do.

Here's the footage of my attempt:
http://www.youtube.com/watch?v=IATtCAwmQVs

We see the surface of a BBW, at 80X magnification. I located a part with one of those red spots and one of the white spots. The entire surface is speckled with those spots, the white ones more sparsely and typically a bit bigger than the red ones. Here's a picture shot with the same equipment at 16X.

I demonstrate how I can scratch a groove in both types of spots, without any crystals emerging large enough to allow a positive identification as garnets, at that magnification. I personally have a hunch that the much smaller reflective spots could be the actual garnets. They do approximate the typical size that scientific studies have reported about the garnets found in Belgian Blue Whetstone.

What the examined spots in the video are, I don't know, and I don't even particularly care, since they are as separate entities too soft to have any influence on the sharpening properties of the stone.

There is just nothing further I can share on the topic. When I stated to think that what Kramm described as Kaolinite spots is the same thing we're looking at here, I merely saw that as additional confirmation that these aren't garnets.

Kind regards,
Bart.