C12K- an interesting one

[natchez]

Hi folks. Woodcraft keeps sending me free shipping coupons, so I bought a large Chinese 12K stone from them. When it arrived I looked at the stone and it appeared to be a bit different than the plain ones I had received before.
Below is a photo of the surface with just water. It has little black squiggles throughout the stone. It finished a Soligen 5/8 just great. Anyone else have squiggles or black in theirs? Any thoughts on this? Thanks

 

[Spivey]

I have no thoughts on this, but I'm interested to hear the thoughts of others. I am planning on purchasing one of these in the near future.

 

[Slartibartfast]

I think glen said the "squiggles" are a sign of a good "CH12k" if i remember right. He had a thread about it over on srp a while back.

 

[natchez]

I have no thoughts on this, but I'm interested to hear the thoughts of others. I am planning on purchasing one of these in the near future.

I sent a PM to you, but repeated the info below for all.

I think glen said the "squiggles" are a sign of a good "CH12k" if i remember right. He had a thread about it over on srp a while back.

I will do a search and see what I can find. Thanks.

For any interested: Here is the item I ordered:
Natural Water Stone, 8" x 2-3/4" x 1-1/4"
Item #144950 $34.99

Free shipping code: "We've got an email special for you! If you place an order of $25 or more and use Coupon Code 10118 during checkout you'll get Free Super Saver Shipping.* It's our way of saying thanks for being a Woodcraft email subscriber! Offer ends October 18."

I have now had four of these come through my hands and this is the first one that looks like this. I lapped the others and kept this and a smaller one, which is plain, and gave the other two as gifts to some friends who are really into collecting knives.

 

[mainaman]

the o ne I used to own had brown figuring , it was pretty decent finisher

 

[SliceOfLife]

Mine had long green streaks that were only visible when wet if I remember right. I wasn't happy with the edges off of it. I've considered trying another seeing as they're so cheap.

 

[zerocover]

Below is a photo of the surface with just water. It has little black squiggles throughout the stone. It finished a Soligen 5/8 just great. Anyone else have squiggles or black in theirs? Any thoughts on this? Thanks

Because its a natural stone, there are large variations between stones. In general the best C12K's are gray with black veins, after you use it a few times it should have a very smooth surface on it.

The black means you have a great stone on your hands. Mine is similar and is also a great finisher. Any other colors or impurities seem to have problems.

 

[Joe Edson]

Mine has those black squiggles as well, but also has a red/orange line running the length of it. I haven't used mine at all, but maybe I should give it a try.

The red/orange line had me worried though that it was some inclusion that could affect honing in a bad way.

 

[natchez]

Mine has those black squiggles as well, but also has a red/orange line running the length of it. I haven't used mine at all, but maybe I should give it a try.

The red/orange line had me worried though that it was some inclusion that could affect honing in a bad way.

Mine has a bit of orange at the end. See below. Perhaps, the black and the orange run together. Give it a try, the worst that happens is you have re-hone a bit. I just pushed a blade over the orange end and did not feel anything off, but then again mine is just orange at the very end. On the upside it may not have any affect and you will get a great edge.

 

[Wid]

I recently bought off ebay that has long black striations with a few orange ones mixed in. I was surprised that in the pic it showed a blue stone and mine is dark gray.

 

[natchez]

Mine has those black squiggles as well, but also has a red/orange line running the length of it. I haven't used mine at all, but maybe I should give it a try.

The red/orange line had me worried though that it was some inclusion that could affect honing in a bad way.

I recently bought off ebay that has long black striations with a few orange ones mixed in. I was surprised that in the pic it showed a blue stone and mine is dark gray.

How about some pics and then we will all be able to see better. Maybe we have a hidden C12K guru who shall upon seeing these pics grace us with some wisdom

 

[Legion]

The orange could be iron oxide?

I just had to go and have a look at mine. No squiggles. Mine is a reasonably even slate grey colour with some slightly lighter cloud patterns. It seems to work OK.

 

[natchez]

The orange could be iron oxide?

I just had to go and have a look at mine. No squiggles. Mine is a reasonably even slate grey colour with some slightly lighter cloud patterns. It seems to work OK.

Could well be that with the rust color it is iron oxide. Being a lawyer and accountant, I would not have a clue. The plain gray stone I have works well, too.

 

[wdwrx]

I also have People's Hone with the exact same black squiggles through it , but only about half as many as yours, and only on one side, the other side has the faintest dark line or vein through it but no squiggles. I honestly haven't used my C12k more than a time or two, though I didn't have anything to complain about the edges I got off it. TBH it's been so long I really can't remember

 

[Wid]

Here it is

 

[natchez]

Here it is

Yes, indeed yours is somewhat similar with more straight-line black. Looks sort of like the side of mine where for about 3/8" of an inch the black shows up more as lines. Wow, no exaggeration- way more orange, but I would still give it a go and see how it sharpens. But, I would not use my better blades until fully vetted. It may actually sharpen just fine. The orange may be like the manganese(?) dark lines that are found in a coticule; the lines look odd but do not affect honing. Thanks for posting the picture. Seeing the variations and finding out how they affect the use of these Chinese stones seems to be something folks have only done a bit of on the forums. Given the really nice edges you can get and the reasonable cost I am a little surprised more has not been explored.

I do keep a test razor or two around, usually either an eBay special or the reliable old Gold Dollar, that I use on new stones to try them out before using a stone with the more pricey blades.

 

[Wid]

I have used it to finish a couple of razors. It indeed does put a real nice edge on a razor.

 

[Woodash]

The orange and strong brown colors are very likely to be hematite (Fe2O3), goethite (FeOOH), or their noncrystalline counterparts. These are common alteration/weathering products of Fe-bearing primary minerals - e.g., magnetite (Fe3O4) or similar - possibly coming from the black 'lines'.

That's hard to say, though, because the ~horizontal hematite/goethite bands on the side of the hone crosscut the thin sedimentary (gray/black) lenses and appear to be younger - possibly the result of later shrink-swell cracking. Without analyzing or at least looking at the stone, it's hard to tell, but the hematite/goethite is a very good bet.

Anyway....

 

[wdwrx]

well there ya go! Harder to get a more definitive answer than that.

Steve, where does hematite/geothite fall on the Moh's scale?

 

[Woodash]

well there ya go! Harder to get a more definitive answer than that.

Steve, where does hematite/geothite fall on the Moh's scale?

I don't know about definative, Chris, but let's call it an educated guess.

I've seen it rated as ~5-6.5 on the Mohs, but this stuff is probably extremely finely-divided and is probably more of a polisher than a cutter - that is, if there were enough of it on this hone to have much of an effect.

This is essentially the red Fe-ox paste that you see all over the place. I have 0.1u Fe-oxide from Larry Whipped Dog. It's hematite (Fe2O3).