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Every thing JADE and about Jade

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Author Topic: Every thing JADE and about Jade  (Read 2364 times)
Michael S Hoover - Redrummd
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« on: December 08, 2012, 10:27:11 pm »

I thought It might be good to start a thread top discuss every thing about Jade and things formed from Jade. 

I thought a good start point would be my test polish table.  I do a test polish on any new Jade I am going to be using.  It helps to keep them together both as I find them pleasing to have in the shop and when I am using a piece I like to look at the polished test piece as I can tell by looking what steps I will be using to get the best polish.

This is very important as scales on a knife are a lot more difficult to polish than a curved surface such as you would get cutting a cab.  In fact, I cannot get quite as good a polish on most knives than that on the test piece.

Here are the test piece Jades I use the most -



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* DSCF4501.JPG (155.45 KB, 768x1024 - viewed 46 times.)

* DSCF4505.JPG (157.71 KB, 1024x768 - viewed 38 times.)
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Michael S Hoover - Redrummd
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« Reply #1 on: December 08, 2012, 10:47:46 pm »

Hopefully you can see that the test pieces are mostly top grade Jades but even these can have serious issues. 

One problem we all face as buyers is determining the quality of a piece being considered.  I thought I would start with a bit about the grain (fly wing size) and why so much Jade being sold is poor quality.

The photos are of a pressure stress outer section from a VERY large boulder mined at the Kutcho mine in British Columbia.  The outer few inches is stressed by the massive forces in the upheavals over millions of years that it takes for the formed Jade to be thrust where the miners can get to it.

This piece has a relatively large grain size and the little "fly wing" structures of the grain can easily be seen in the photos of the outer edge.  On the cut side you can see the stress structures.  This whole piece is pretty much scrap as it will act like the flakey Croissant when being cut or when being ground to shape it.  This flaking issue can be problematic with Jade even as 12 inches from the outer surface and there is no way to see any evidence of it.  Cutting curves does not cause this issue as much as doing grinding of a straight edge as I need to work with knives.  There are ways to observe this concern when doing the cutting to shape on a slab in a trim saw or on a bandsaw.  You watch right where the blade is cutting to see if tiny flakes are being dislodged. 

I think that is enough information to digest so here are the photos -



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* DSCF4512.JPG (154.49 KB, 1024x768 - viewed 26 times.)

* DSCF4513.JPG (142.66 KB, 1024x768 - viewed 29 times.)
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Michael S Hoover - Redrummd
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« Reply #2 on: December 08, 2012, 10:55:27 pm »

When slabbing a piece that has this "damage" you will often note the "Croissant" flaking in you slab saw.  This is a really good indication that your piece of Jade is going to be tricky to work or totally junk.

I also took a photo of the face of the Jade piece in the saw and you really cannot see the stress damage. 

In the Jade yards the outer edges are all sawn off to get the solid heart of the Jade to be a huge block.  The blocks are sold commercially and the cut off pieces tend to be what we can buy.







* DSCF4510.JPG (143.27 KB, 1024x768 - viewed 34 times.)

* DSCF4515.JPG (168.59 KB, 1024x768 - viewed 26 times.)
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Michael S Hoover - Redrummd
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« Reply #3 on: December 08, 2012, 11:02:26 pm »

Now these issues show why it is really hard to buy Jade from Ebay photos.   I should note that the pressure scrap piece is just one end of a big piece from Kutcho that was selected for me by Kirk Makepiece.   It is actually VERY unusual in that it has good color and most of one side is full of dendrites!

Here are some photos of a backlit slab and a polished large cab.  This cab is about 3 1/2 inches tall.



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* DSCF4496.JPG (156.86 KB, 768x1024 - viewed 19 times.)

* DSCF4491.JPG (140.54 KB, 768x1024 - viewed 23 times.)
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Michael S Hoover - Redrummd
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« Reply #4 on: December 08, 2012, 11:09:47 pm »

There are some things you can do to help determine how good a piece is.  Tight grained Jades have really tiny "fly wings".  Cut edges are very "crisp" - sharp edged.  Fine grained slabs have a very high "chime" and sound like porcelain when tapped together.  It is unmistakable when you hear it.

The tight grained pieces usually polish more easily and get a better polish than the larger grained Jades.   How hard the Jade is also impacts how easily the Jade will polish.

Jades that have a very "swirled" mix of colors are always much tougher to polish.

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« Reply #5 on: December 08, 2012, 11:27:13 pm »


Interesting to say the least.  This is something to read and re-read.  I have quite a bit of jade so I'll have to study this real good.
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Michael S Hoover - Redrummd
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« Reply #6 on: December 08, 2012, 11:32:18 pm »

I suspect the question a lot of you have is how do I polish the Jade.   I use the same basic "plan" for all of the Jades I use.  The more prone the Jade is to be tough to polish the lower the stage of the sanding I do is what I change.

The basic plan is to sand to 1200 and then take a aluminum marker and pretty much mark all over the piece and then go back to the 1200 grit.  For fine grained Jades the marking will be gone in seconds and that is a good indication that it will also take a high gloss polish.  I sand to 14K and then go to the ZAM buffer for a final light pass.

If the aluminum markings do not almost immediately get removed I know I have a less tightly grained piece.  I then take the piece to 3K and sand it smooth.  I dry the piece and look at the polish.  If it has a good polish I go to 8K and sand it and dry it.  If it improves I go to 14K and sand it.  If it improves I go to the ZAM for the final light buffing.

Now the question is what is done if going to the next higher grit does not improve the polish but develops a duller polish or orange peel.   You need to go back to 1200 and get a clean smooth finish again and then to the wheel that gave you the best polish which may be a dull wax look to even a almost suede look.

Once you have the best polish do a light dusting on the ZAM wheel and check the polish.   Then I go to a Fasbulstre wheel and do a light "sanding" and then go back to the ZAM wheel to polish.  If the polish did not improve that is as good as it will get with my process.

If it did improve I go back to the Fabulusre wheel and another light sanding and back top the ZAM to see iof it still improved.  Some Jades take up to 4 passes to get to the best possible shine.

Fabulstre removes a tiny bit of the Jade as it has a bit of abrasive effect.  This means that with every light sanding the orange peel effect gets worse.   What I am doing is looking for the best balance between polish and the orange peel texture.

I use neutral shoe polish on the Fabulustre wheel too.  That makes the buff wheel stickier and helps hold the Fabulstre on the buff.   I think it improves the cutting action too.

The buff wheels are the sewn type.  I use 3/4 inch (72 ply I believe) wheels and remove two rows of the stitching on a new wheel to get it to be fluffier.  Just spread a layer and use a single edge razor blade to cut the stitching.
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mick B
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« Reply #7 on: December 09, 2012, 01:37:20 am »

Great info Michael, working jade can be a challenge, so many different techniques and different sanding and polishing procedures used on different locations and types, I have had help from top NZ carvers over the last few years with sanding and polishing, I no longer use waxes of any kind, nor will I start a carving with visible cracks. There are three locations in my area that I get my jade from, and all need different sanding and polishing techniques, my jade fish hook in the bead comp was polished with linde A, its as hard as BC polar, the material I gave David Southerly is from another and it will not polish on Linde A, orange peels badly, its softer but a tighter grain and only diamond works, I constantly try new things, I have polished jadeite with bamboo with no compound at all, it contains fine silica quartz crystals that acts as the polishing abrasive, in Burma and China they wax dip sometimes, this gives extra depth and gloss, love reading your posts and keep them coming.
Cheers mick B
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« Reply #8 on: December 09, 2012, 09:52:10 am »

Excellent topic and set of posts Michael! yes
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« Reply #9 on: December 09, 2012, 10:07:15 am »

Mick - I had no idea 'til you mentioned it - very interesting:

Src: http://waynesword.palomar.edu/ecoph39.htm
"
 In addition to cellulose and lignin, the thick-walled fibers of bamboo also contain up to five percent silica in the form of silicon dioxide (SiO2). Although bamboo culms do not have the structure of true wood, they are very hard because they contain silica and lignin.
"
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« Reply #10 on: December 09, 2012, 11:10:01 am »

I've asked Aaron to pin this.  I don't have that power in this section of the forum.  I believe this to be a great thread to direct folks with Jade questions to.  Let's build on this thread with more Jade knowledge so it can be a great resource. Anyone who has other Jade pointers please feel free to add in photos and information.  yes
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Mary Ann
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« Reply #11 on: December 09, 2012, 11:37:21 am »

Wonderful information! Thank you for sharing it Michael. I am going to print it out for easy reference.
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thewrightthings
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« Reply #12 on: December 09, 2012, 12:05:36 pm »

Michael,
 Thanks for taking the time to post all that information.  I have accumulated quite a bit of jade from Alaska and New Zealand and have been hesitant to get started on doing anything with it.  This will certainly help.
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« Reply #13 on: December 09, 2012, 01:33:40 pm »

Great topic. I am looking forward to learning more. Jade really has a fibrous structure so I can see how the "wings" might determine quality. The tighter bond the fibers have to each other, the better quality. I would think it would polish better too. Jade is such a mysterious gem. What about directional cutting of the rough? Would cutting and polishing in a certain direction produce a better polish, some gem material does. I have never experimented with jade, just thinking of the possibilities. Neat topic, Eric(Ajo)
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« Reply #14 on: December 09, 2012, 04:16:36 pm »

Wow Michael, thanks for the great info!
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