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Black Jade

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zurn
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« on: December 03, 2015, 03:03:57 pm »

Hello
Im looking for a black jade slab
I figured everything would be the place to start
Thanks
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slabbercabber
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« Reply #1 on: December 03, 2015, 04:28:53 pm »

Are you looking for absolute black (hornblende) or Wyoming black jade.  I have the latter.
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lithicbeads
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« Reply #2 on: December 03, 2015, 04:33:15 pm »

The Arizona materiel is not jade . Black has become fairly expensive but there has been quite a bit of Cowen Australia black at rock shows. This can be premium black but black from all areas can be plagued with small white inclusions of feldspar .
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« Reply #3 on: December 03, 2015, 11:23:18 pm »

As mentioned, the black jade is getting kind of pricey.  I walked around on the beach a few months ago and picked up some of the black rock that looked like it would take a polish, then brought it home and checked it out.  It worked up pretty good for the price.  Here are the pieces I picked up and a pendant I made from one of them.

 

You might want to walk around on the beach and save a little money.  yippie  My 2 daughters and wife all got a pendant as a souvenir from the beach cabins we were staying in & they loved them.
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zurn
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« Reply #4 on: December 04, 2015, 02:37:33 pm »

Hi all
slabcrabber being new I dont know the difference
as i am also finding true black jade can be pricey
I may start out with the suggestion from  mossy which by the way nice find
those look great nice polish
but I will remember you offerslabcrabber
Thanks all
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« Reply #5 on: December 16, 2015, 11:08:21 am »

Strictly speaking even Edwards is not "jade" since the word jade includes only materials identified as either nephrite or jadeite.

I have never seen a GIA report which will commit to identifying any black amphibole as nephrite.

So if this is the case then we have to understand that the gemstone community is using the term "jade" loosely and if we say it's OK to call Edwards Black Jade jade then we should also be able to call the Arizona material Absolute Black Jade.

I have some pages on Black Jade on my website here:

http://www.finegemdesigns.com/blackjadesnavigation.htm

Note: I will be adding some information about Black Jadeite soon since I have some samples from Guatemala.
This material can't ever be disputed as a jade since it is actually JADEITE.

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Michael S Hoover - Redrummd
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« Reply #6 on: December 16, 2015, 03:26:41 pm »

Strictly speaking TRUE Edwards Black jade is Nephrite.  Here are the test results from 2011 from the University of Washington's Geology Department -

________________________________________
From: xxxxxxxxxxxxxxxxxxxxx.net [mailto:xxxxxxxxxxxxxxxxx.net]
Sent: Friday, October 07, 2011 9:37 AM
To: Michael Hoover
Subject: Re: edwards black

Hi Mike
the Edwards has been tested and more tests will be performed to hopefully include talking George into taking it into the SEM.
It tests better than any BC jade for sure,
and tested better than the Wyoming green piece I got from Agren.

Appears to be a super nice actinolite-tremolite nephrite jade with nice high peaks for tremolite.
I found no evidence of quartz which is defined by specific 2 theta peaks on the graph readouts.

There is a graph peak near one of the known and predominant qtz peaks,
but it needs to be ferreted out with d-spacing data as I cannot identify yet,
and I have been using 2 theta peaks for determinations.
That specific peak is not only too far from the precise qtz peak,
but it is not accompanied by the required other qtz peaks to be qtz.
It probably is an unascribed actinolite peak not found in the data reference I use.

George is going to coach me on using a seriously complex data book on d-spacing,
and I have done some d-spacing work as opposed to just 2 theta data,
and that should help the finer tuning of data.

You will see the 2 theta peaks on the graph,
and those will have numbers like 10.52, ...28.6... etc, and the d-spacing values will be listed just below the 2 theta values.

A problem occurs when using the machine.
When the chem grad students are using it profusely then the machine XRay tube  is super warmed up,
and we have seen that overall data produced per specimen is little on the low side of text data.
This is a problem when comparing actinolite to tremolite at certain peaks.... or even hornblende for that matter.
However, there are certain tremolite peaks that actinolite and hornblende cannot have.
Those are definitely present in almost all samples seen.
Also when packing slides with powderized sample material;, if they are packed too low, data gets skewed a pinch.
I may have to go to a different method of slide prep.
I use aluminum packing sample slides, and there is a different approach available,
but I have to have permission to use that method.


Your Edwards Black is superb material.
You can just see it and feel it when handling it.
The hardness results not from the quartz suspect, but most likely from the tremendous character of this specimen itself,
representing intensely interlocked fibers of actinolite-tremolite.
It exceeds 95% of all the salt water beach black in quality. 
I have tested a couple of beach black pieces that tested better than the Edwards in tremolite and actinolite peaks,
but no matter what,
the beach black stuff here will have a percentage of feldspars... though often slight,
they do compromise the hardness and the purist of blackness desired.
We also have a genre of "green-black" from the beaches here that tests well.

The Edwards had no discernable chlorites to consider whereas ALL Washington nephrites
will display some level of chlorite,
from minute to inundated.
I have seen however ...Washington nephrites with explosive tremolite levels exceeding anything anywhere else,
and that could mean a host of explanations,
so until better authority is approached with cumulative data,
I cannot comment on that phenomena.
ie
I need to extensively talk to George Mustoe,
but I need to organize specific data sheets to specific questions etc,
and ultimately,
puzzling data and samples go into the SEM ...electron microscope

I will have to review the BC jades but my memory is that there were no chlorites in those either.

There will be more testing on your pieces as time goes on.

I will send you a copy of the XRD data sheet on the Edwards.
If I were you I would back pocket that untill more data is produced from those samples.

Can you open attachments with images?
If so I can send an image of the XRD data.

You are welcome to have other items tested if they warrant the effort I have to produce in doing so.
Often I leave the university at midnight to 1 AM when done testing after 5 hours of work on prep and testing and cleanup of labs,
and I do this late in the evenings because nobody else is there,
so I don't get in the way of grad students etc.

Thanks
Vic

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« Reply #7 on: December 16, 2015, 03:35:53 pm »

Here are photos of the tested piece of Edwards and a photo of Edwards Black being held by the Grandson of Edward's.



* Edwards Jade Wyoming 2.JPG (970.66 KB, 2304x1728 - viewed 15 times.)

* Edwards Jade Wyoming 3.JPG (879.9 KB, 2304x1728 - viewed 18 times.)

* Edwards Black jade displayed by his grandson.jpg (47.14 KB, 620x490 - viewed 17 times.)
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« Reply #8 on: December 16, 2015, 03:58:14 pm »

Another piece of what I believe is Edwards Black. This was inherited from an old friend who passed away. His collection of rocks dated back into the 40's.  I've noticed with this piece that if a strong light is aimed behind a very thin edge that the material is really a very dark green. Almost black. But on a solid polished surface it is a true black.

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« Reply #9 on: December 16, 2015, 04:46:42 pm »

If anyone here can produce a GIA report that identifies Edwards as nephrite I will gladly agree with the assessment.

I think though there are several reasons why the GIA will not do this.

1. There is considerable debate as to whether "nephrite" is even a specific rock. For example:

[QUESTION] "The problem is there are many variations of amphiboles with varying percentages of different minerals so how is it even possible to 100% define "nephrite?"
 
[ANSWER] "We do not need to 100% define Nephrite based on exact composition.  It is a GENERAL descriptive term applied and used to describe a massive rock made up of a single or variable amphibole minerals that have been changed by heat and pressure (metamorphosed ) to a tough felted mass if interlocking fibers The fibers are actual micro crystals of the amphibole mineral and retain the structural chemistry  of the original mineral.  I have a beautiful piece of apple green jade that has a thin skin of altered white and cream colored rind and under the microscope at 30 X,  you can see the distinct fibers in the felted structure. I wish I had a camera attached to my scope or send you a picture of it. A good comparison of felted material is to look at a high grade felt hat under the microscope and observe the fibers They are highly dense and woven or felted together.( try tearing good felt!  )  In good quality nephrite jade, the micro crystals look much the same way but without the air between them as they have grown together to form a solid mass.he air between them as they have grown together to form a solid mass."

 Credit: Glenn Laidlaw (wrminerals) Wind River Minerals

And this:

Definition of "nephrite."

"Nephrite is a member of the solid solution series Tremolite-Actinolite-Ferro-Actinolite. You can think of this series like a tetter totter where one end is the magnesium rich end member (Tremolite) and the iron rich end member Ferro-Actinolite on the opposite end. Actinolite which has both magnesium and iron in the middle at the balance point. To complicate the situation nephrite is considered to be somewhere between tremolite and actinolite in chemical composition. The higher the magnesium content in the formation process the lighter colored the mineral will be. Iron departs the green color so the more iron the greener the color to which point  it will appear black."

Credit: Credit: kennyg
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http://gemstone.smfforfree4.com

And finally this:

[QUESTION] Is Edwards Black Jade nephrite?

Note: Glenn Laidlaw (quoted above) has 35 years of experience with Wyoming minerals and had some Edwards Black Jade analyzed on two separate occasions.

 [ANSWER] "Most of the black Jades are a iron rich, actinolite based felted rock produced through metamorphism. Many of the black jades in the wyoming jade fields fit this description also. But the Edwards mine material has a slightly different appearance and properties. much less of the felted structure and no inclusions other than a ocasional relic quartz xtal replacement near the vein walls. I have collected material, small chips of jade from the mine dump and they have a range of colors from olive green to pure black at the site. The Wyoming State geologist, Wayne Sutherland, visited the site with me last summer and collected samples.

 Before that, the Wyoming Geo Survey said that it had tested the material out as iron rich actinolite.

 I have not seen his report on the material he collected that day. I did give a sample to Gunnar Farber of Samswegan, Germany.

 Gunnar is a friend and a international rare mineral dealer who has the equipment to differentiate the cation ratios that define the endless varieties of the amphibole family and he told me that he found the piece I gave him to be a pyroxene called Pigeonite (!) with small inclusions of Pumpellyite ( another rock forming silicate mineral ... there are about 5 recognized varieties )."

 Credit: Glenn Laidlaw, Wind River Minerals

So it would appear that we have conflicting reports. Some say Edwards Black is nephrite and others will not commit to this name for reasons stated above.

But nobody can dispute that the GIA is the final authority that the public trusts to make gem identifications.

And I have yet to see a single GIA report that will commit to using the term "nephrite" for ANY black amphibole including Edwards Black. This is because the word "nephrite" is a GENERAL DESCRIPTIVE term.

So what is the point? The point I'm making is that the folks at greatslabs.com have as much right to call their Arizona material black jade as people who call Edwards Black jade. There are people who would like Edwards to be the only black amphibole to be classified as nephrite but this not supported by the data.

I'm NOT saying Edwards isn't a wonderful material. It is the best combination of black and toughness I've seen among black amphiboles.

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« Reply #10 on: December 16, 2015, 08:36:33 pm »

finegemdesigns - Nephrite requires both tremolite and actinolite and a correct specific gravity range.  If you can get me a absolutely verified piece of the Arizona material I will see if I can get it tested. 
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« Reply #11 on: December 16, 2015, 09:27:05 pm »

finegemdesigns - Nephrite requires both tremolite and actinolite and a correct specific gravity range.  If you can get me a absolutely verified piece of the Arizona material I will see if I can get it tested. 

I don't need you to verify anything. All the data is freely available in my above posts and on my website. Refute anything I've posted or stop saying [applies to  lithicbeads etc.] Edwards is the only true jade based on the flawed premise that Edwards is the only black amphibole that can be called nephrite.

In case you are wondering I have a lab report that calls Boots Black (Black Jade Actinolite) nephrite also. See here:

http://www.zbestvalue.com/LabReports.htm

But on that page you will also see a GIA report that will not commit to the term nephrite. So if Boots Black is nephrite then it's also "jade" by definition. Which kind of ruins the idea that Edwards is the only black amphibole that deserves the term jade.
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« Reply #12 on: December 16, 2015, 10:20:29 pm »

Please, do not put "words" in my "mouth".  I have never written ANYTHING like this: " ...stop saying [applies to  lithicbeads etc.] Edwards is the only true jade based on the flawed premise that Edwards is the only black amphibole that can be called nephrite."

There are actually a lot of black Nephrite Jade's.  True Edwards is one of them. 

I have never given you an argumentative posting and I was offering to ask the University of Washington to test the Arizona stone to see if it was truly Nephrite.  I and most others who collect or work with Jade find the University of Washington to be trustworthy in testing and identifying Nephrite.  It is costly to do these tests in personal time and in run time on equipment in the lab that costs millions.

Why you got all wrapped up tight over a kind offer is beyond me.  Chill man.....   walker
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« Reply #13 on: December 17, 2015, 12:08:29 am »

Please, do not put "words" in my "mouth".  I have never written ANYTHING like this: " ...stop saying [applies to  lithicbeads etc.] Edwards is the only true jade based on the flawed premise that Edwards is the only black amphibole that can be called nephrite."

There are actually a lot of black Nephrite Jade's.  True Edwards is one of them. 

I have never given you an argumentative posting and I was offering to ask the University of Washington to test the Arizona stone to see if it was truly Nephrite.  I and most others who collect or work with Jade find the University of Washington to be trustworthy in testing and identifying Nephrite.  It is costly to do these tests in personal time and in run time on equipment in the lab that costs millions.

Why you got all wrapped up tight over a kind offer is beyond me.  Chill man.....   walker

Why is your lab better than any of the labs I've mentioned? Maybe because they give you the results you want?

This IS a big deal by the way since the public knows very little about the nomenclature of these materials. Folks that make such a claim like Edwards is a jade and Arizona is not hurt the ability of some people to sell their jade.

For example what if I went public on TV and the big Tucson shows and convinced everyone that Arizona was true jade and Edwards was just a random amphibole? Then the shoe is on the other foot and you would find it difficult to make more money with Edwards knives. Think about this before you label me as a troublemaker.

Oh and if you had read my post carefully (re: words in my mouth) you would have seen that I specifically referred to the person above who made the claim that Arizona is not a jade. So you don't need to be offended by something that wasn't directed your way. (unless of course you agree with that person)
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« Reply #14 on: December 17, 2015, 08:02:44 am »

First of all, even Rob Kulakofsky, who owns ColorWright (Great Rough, Great Slabs, etc.) says in his description of of Absolute Black that it is not true jade:

"Absolute Black "Jade" Rough
Absolute Black "Jade" is gem grade ferro-hornblende and not a true jade. It is absolutely black, with no green undertones, just like the Edwards black jade mined long ago in Wyoming. Absolute Black "Jade" is denser and has a higher refractive index than true jade. Absolute Black "Jade" quickly takes a higher polish than can be obtained with true jades. Unlike black onyx, which is dyed chalcedony, Absolute Black "Jade" is completely natural. Excellent material for inlay, cabochons and beads. Mohs hardness 6.5."

Second, play nice.  Most of the folks on this board are upstanding people who are truly interested in knowing exactly what the material they have is.  Slandering members will not be tolerated.  Nobody on this board that I know of wants to sell material as something it isn't, so if there is an offer of testing to find out what it is, take it as exactly that -- an offer.

'Nuff said.
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« Reply #15 on: December 17, 2015, 09:19:30 am »

What started out as a simple request for a slab of black jade seems to have turned into a full blown battle over what is & what is not black jade.  A my lab is better than your lab is.

I was following this thread in hopes of gaining knowledge,  Instead I find myself  reading a cheap novel.  Grow up &  act like gentlemen.
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« Reply #16 on: December 17, 2015, 11:31:37 am »

      Oh come on Don, some of us are enjoying this.  This is one of the big dilemmas in the rock business that affects all rock hounds and collectors. I have frequently bought rough and slabs from long time dealers that had been misidentified. One of the big sellers who posts here at times once told me " if they said it was XXXX when I bought it, that is what I sell it as." I actually appreciate when these discussions occur as it can be a good learning tool, sometimes. When I buy or cut stones my biggest concern is if it is pretty. But many people place more value on name that beauty. Just look at the crap they sell on e-bay called Owyhee picture jasper.

 
    throw Jake a biscuit for me
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« Reply #17 on: December 17, 2015, 12:57:15 pm »

First of all, even Rob Kulakofsky, who owns ColorWright (Great Rough, Great Slabs, etc.) says in his description of of Absolute Black that it is not true jade:

"Absolute Black "Jade" Rough
Absolute Black "Jade" is gem grade ferro-hornblende and not a true jade. It is absolutely black, with no green undertones, just like the Edwards black jade mined long ago in Wyoming. Absolute Black "Jade" is denser and has a higher refractive index than true jade. Absolute Black "Jade" quickly takes a higher polish than can be obtained with true jades. Unlike black onyx, which is dyed chalcedony, Absolute Black "Jade" is completely natural. Excellent material for inlay, cabochons and beads. Mohs hardness 6.5."

Second, play nice.  Most of the folks on this board are upstanding people who are truly interested in knowing exactly what the material they have is.  Slandering members will not be tolerated.  Nobody on this board that I know of wants to sell material as something it isn't, so if there is an offer of testing to find out what it is, take it as exactly that -- an offer.

'Nuff said.

As mentioned above these discussions may get heated but this doesn't mean they shouldn't take place.

As to your specific post yes greatslabs.com is hedging on their description of their jade. Why? because they understand that the debate is still ongoing and they don't want to get into trouble later. Here is a sample scenario:

1. Person buys a piece of Arizona Absolute Black Jade.
2. This person then makes a diamond and black jade ring with said jade.
3. This person then sells this ring to a client.
4. Client decides to sell the ring and to do so gets a lab report from the GIA.
5. GIA report comes back as diamond and black amphibole.
6. Client gets angry since now they can't sell their ring because the GIA won't commit to the term nephrite and therefore by definition will not commit to the term "jade."

This is a very logical approach by greatslabs.com to protect themselves and their business.

It does NOT however prove that the Arizona material is any less a jade than Edwards.

The same scenario would happen if the stone was Edwards because as far as the GIA is concerned they are simply BOTH black amphiboles.

The gemstone community has as a group been using the term Absolute Black Jade for many years now. You never hear this material being called Absolute Black Amphibole. The community has spoken and the fact that a few Edwards Black enthusiasts disagree doesn't change the overall consensus.
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« Reply #18 on: December 17, 2015, 05:32:59 pm »

If anyone wants to get personally invested in the debate - I noticed there's a 20-lb lot of Edward's Black (fill in the blank) on eBay right now for only $4,000. I have no knowledge of seller or personal interest in listing - just sharing!

-Jeremy
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« Reply #19 on: December 17, 2015, 05:59:41 pm »

   I love jade but I am no expert by any means. But at $200 a pound I would need to see a polished section, a slab both front and back lit and a return policy of no questions asked. I am sad to say integrity is not the most common thing even among sellers of jade, jaspers and agates for under $20 a pound. Just because a rock sells by the pound and not the carat does not mean it is not important to be precise about it's origin and description. I am amazed at how many sellers at rock shows sell material that is incorrectly identified. Original Owyhee jasper and Regency Rose Plume Agate are two that I find at every show and all over the internet that are improperly identified in order to get a better selling price.
        This is why discussions like this one are vital on an open internet site like this one.    While all the politeness is warming we do need to call a spade a spade at times. When you start bending definitions to fit in a special rock or location all Hell should break loose. Look at what Etsy and Amazon now define as hand made. So let us keep Jade as Jade and not start sliding down the slope of.. well, it is like jade, looks like jade, similar to jade. Then we can move onto what is natural Turquoise... ahhhhhhhh....   sorry.
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« Reply #20 on: December 17, 2015, 07:30:48 pm »

By all means, have your discussion.  That is the whole purpose of this forum.  Just do it civilly. 
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« Reply #21 on: December 17, 2015, 08:18:17 pm »

I will state that a ferro-hornblende is not Nephrite and if proper testing has already been done  on Absolute Black "Jade" then there really is no further Washington University testing necessary.  Anyone wanting to buy Nephite would not buy a ferro-hornblende so it would be a waste of my resource to ask for a re-test.  If you read the note to me from the UW testing I think you will see what I and the University need to see to declare a test piece as Nephrite Jade.

I will state again that there are a lot of true black Nephrite Jades which includes TRUE Edwards Jade.  I include in true black all that appear black to the human eye as if cut down to 1/100 to 1/1000 inch they may show to be actually a dark, dark, dark green.

The reason I keep noting that TRUE Edwards Black Jade is Nephrite is the fact there are a lot of Black true Nephrites from Wyoming, Washington and British Columbia that have been tested at the University of Washington.  Edwards Black was pretty much mined out down to about 50 feet in the late 1950's and then in the 1960's a bit more down to 65 feet.  A lot of the chips and other black material in the tailings were not Jade.  This paragraph is done from my memory and may be a bit off on depths and timeframes so it is not guaranteed to be 100% correct.

I should note that UW is only testing Jades from the US and Canada and there are probably true black Nephrite Jades from other locations.

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« Reply #22 on: December 17, 2015, 08:27:43 pm »

By all means, have your discussion.  That is the whole purpose of this forum.  Just do it civilly. 


This is exactly what I meant in my comments. Keep it civil. No more, no less. I saw that the conversation was beginning to turn mean spirited, so I spoke out.
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« Reply #23 on: December 17, 2015, 08:50:31 pm »

Thank you, Don!   hugs32
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« Reply #24 on: December 17, 2015, 09:07:34 pm »

As a closet science geek, I like to see **** test results. Lots of us out here not conversant in the finer technical details, but who can be comfortable with "x,y,z in this rock equals x,y,z in that rock".

After reading this thread, I found cool stuff like Jadeite has a specific forumula - Na(Al,Fe3+)Si2O6 - according to one source, while Nephrite is described as "...felted amphiboles of the tremolite - actinolite series. In addition to amphibole, nephrite can contain minor to trace amounts of diopside, grossularitic garnet, magnetite, chromite, graphite, apatite, rutile, pyrite, datolite, vesuvianite, prehnite, talc, the serpentine polymorphs and titanite." No specific formula in that description.

Then there's this:

http://www.gia.edu/jade

-----

Mineral:  Jadeite and Nephrite

Chemistry: NaAlSi2O6 and Ca2(Mg,Fe)5Si8O22(OH)2

Color:  Green, white, orange, yellow, lavender, black

Refractive index:  1.666 to 1.680 (+/-0.008) and 1.606 to 1.632 (+0.009, 0.006)

Birefringence:  Usually not detectable

Specific gravity:  3.34 and 2.95

Mohs Hardness: 6.5 to 7 and 6.0 to 6.5

-----

So let me ask if I've got this right. All Nephrite is an Amphibole, but not all Amphiboles are Nephrite. If something fits the GIA formula and properties, then it is Nephrite. Right? Biggest problem is that there will always be discussions like this when commonly (mis)used trade terminology come into play.

Now - everyone break out the lab results. Heaven forbid scientists would ever disagree about anything.

It's all good. I've learned more tonight about Jade than I ever thought I would know. Thanks, guys!
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« Reply #25 on: December 17, 2015, 09:37:35 pm »

Always good advice , " caveat emptor".
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« Reply #26 on: December 17, 2015, 11:51:18 pm »

There really isn't anything new here so unless this changes my posts stand.

Agree or disagree, anyone who views this discussion carefully and does the research can make their own choices on how to proceed when buying, selling or working with these various jades.

I hope this post qualifies as civil.
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« Reply #27 on: December 17, 2015, 11:59:49 pm »

For those interested I get most of my Jade through Jade West and they carry my knives in their stores.

The GIA site has the most recent October 2015 GIA article which was heavily contributed too by both Kirk Makepiece and his daughter Nikki.  Heck, they even have a photo of the two of them in the article and it is a very comprehensive overview of the current Nephrite market.  One of my most proud moments in my work with Jade was the fact that Kirk gave his daughter and husband Paul, a set of kitchen knives I did for their wedding.  So, yes with my work with Jade from the Jade West mines  -  I am a bit tied into the mining and sale of Nephrite including into China.

Here is the link: -

http://www.gia.edu/gia-news-research/nephrite-jade-road-evolution-green-nephrite-market
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« Reply #28 on: December 18, 2015, 06:11:02 am »

I am not an expert my any means but  I have worked quite a bit of jade of many colors though and what I make the most are solid jade rings (no metal). Jade is the only thing tough enough to hold up as a ring and I have tried a lot of other stones to prove it. For example agate, quartz and jasper rings won't last a day on the finger without breaking.

Nephrite and jadeite rings will break but it takes one hell of a whack on steel or stone to break them. I have not been able to break one on wood or composite table top (the cheap veneer). This is a crude and non expertite testing method but it works for me. I break test to the point of bruising my hand so I do not sell junk but the ones I give away are not tested to extreme for pain sake.

I had heard rumors and rumblings about Arizona black jade but could not find any and the other people looking for it could not find any or a location. Bang, Arizona black jade on the market but was told it was not jade. I had to know so I bought some at an exorbitant price to check it out because at times I want true black for other projects.

I did my testing and I would NOT give away a ring made from the Arizona black whatever. I have not had the opportunity to make a ring from the Edwards but I have other black jades (really really dark green) and all of them hold up quite well. Some of what I have I am not sure where it came from but one is from an extinct mine in Joshua Tree CA. It may not have a GIA but I would sell it as a ring even though the end on a couple of pieces have an excessive amount of tremolite which I stay away from.

After all those words I probably could have just said "stay away from the AZ black ?stuff? that is on the market unless you are just looking for a black rock". I have a copy of an article from a prominent rock and gem magazine that states "one in twelve tests at the Smithsonian said it was nephrite" so when the owner of the ?stuff? saw that one test it must have been enough for him to say it was nephrite.

 dunno dunno dunno
Jim
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« Reply #29 on: December 18, 2015, 07:09:05 am »

finegemdesigns - it did and thank you!   dancer5
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« Reply #30 on: December 18, 2015, 11:44:53 am »

One of the questions asked was that all nephrite is amphibole but not all amphiboles are nephrite.  This is correct as nephrite requires the amphibole crystals to be felted which is what give nephrite its strength.  If the crystals are elongated but not felted you will have an asbestiform variety of amphibole in the tremolite-actinolite solid solution series. 

So the answer is that nephrite is amphibole but not all amphiboles are nephrite.  It all depends on the formation.

Bob Johannes
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BSc. Geological Engineering '85
Colorado School of Mines
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« Reply #31 on: December 18, 2015, 04:15:41 pm »

Ah, so! Thank you. I wondered what made the difference - if it was a difference in the mineral makeup ("recipe"), or what. Your explanation helps crystalize (aaargh) this new knowledge within the rocky structures of my brain.

When you said "asbestiform" I looked up chrysotile, but see it's in the serpentine group. A completely different recipe. Thanks again.
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« Reply #32 on: December 18, 2015, 04:47:14 pm »

The "asbestos" minerals are Chrysotile which is a serpentine and the amphiboles; Tremolite, Actinolite, Crocidolite, Anthophyllite, and "Amosite" which is actually the solid solution series cummingtonite-grunerite.  There was a battle a few years ago during the clean-up of Libby Montana as to whether or not the Libby amphibole could be called asbestos as it was not tremolite or actinolite but one of the defined minerals in the solid solution series.  EPA won that one so any amphibole with releasable fiber greater than 5 microns long and a 3 to 1 aspect ratio is asbestos per the EPA's regulations.  I know all this as I have been a state asbestos regulator for the last 24 years.

Some of the material I have seen sold as ghost jade would probably be classified as asbestos under the regulations.  Most "nephrite" has too tight a felted structure to release fibers so cannot be classified as asbestos.

Bob Johannes
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« Reply #33 on: December 18, 2015, 05:22:50 pm »

How does this Australian material factor into this discussion? For sale on thegemshop's site - says it's comparable to Edward's Black and is "Nephritic".

-Jeremy

http://thegemshop.com/collections/rough-rock-1/products/black-jade

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« Reply #34 on: December 18, 2015, 05:43:07 pm »

The fracture line and grain does not look like any I have seen on Nephrite.  It is very difficult to be definitive from a photo.
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« Reply #35 on: December 18, 2015, 06:37:52 pm »

"The definition of nephrite is even more controversial. Mineralogy texts have traditionally listed nephrite as a variety of actinolite, a monoclinic member of the amphibole group. As in the case of jadeite, however, actinolite is very closely related chemically and structurally to other members of its group. Actinolite [Ca(Mg,Fe),(SiO,),] is so closely related to tremolite [CaMg, (SiO,),] that their optical and physical properties may be indistinguishable. The magnesium in tremolite is commonly replaced by iron, and the two minerals do, in fact, grade into one another. The color of the material. however. indicates the amount of iron present: the iron in actinolite imparts a green to grayish-green color, whereas the iron-poor tremolite is normally white to gray. The fact that nephrite is, in reality, a variety of two mineral species recently led the International Mineralogical Association (I.M.A.) to discredit nephrite as a valid mineralogical variety."

Source: THE JADE ENIGMA By: Jill M. Hobbs

"Although nephrite has been "discredited" so far as referring to any known mineral species by the CNMMN [Commission on New Minerals and Mineral Names] of the IMA [International Mineralogical Association], it seems likely that it will persist in the world of gemology."

Source: http://www.dolphingems.com/Completeview.aspx?code=Nephrite_Jade&cat=Gemstones&subcat=Stones

And here is the International Mineralogical Association website with complete list of minerals:

http://nrmima.nrm.se/

So this supports my earlier contention about "nephrite" in agreement with Glen Laidlaw:

 "It is a GENERAL descriptive term"

Glenn Laidlaw (wrminerals) Wind River Minerals
Glenn Laidlaw (quoted above) has 35 years of experience with Wyoming minerals and had some Edwards Black Jade analyzed on two separate occasions.
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« Reply #36 on: December 18, 2015, 07:08:30 pm »

So - in general terms - anything that fits into the parameters of the GIA fact sheet info is in fact "nephrite" jade?
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« Reply #37 on: December 19, 2015, 07:01:21 am »

Bob;    Could you explain your statement " If the crystals are elongated but not felted you will have an asbestiform variety of amphibole in the tremolite-actinolite solid solution series. As you can see in the pictures I attached I had jade that crumbled in the saw. When I turned it to cut with the grain it was excellent and made great cabochons. Mike H. explained to me this is not all that uncommon in lower grade jades. I am just concerned this could contain asbestos and be dangerous.


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* IMG_7666.JPG (2734 KB, 3456x2304 - viewed 7 times.)
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« Reply #38 on: December 20, 2015, 07:55:36 am »

55fossil,

I would describe the block in question as having layers of felting with weak layers in between.  This causes it to break up when cut across the layers but hold together when cut with the layers. 

I would not consider this to be dangerous as ling as it is worked wet as any amphibole should be or with the use of appropriate breathing protection; a well fit respirator with p100 filters.  The P100 are specifically designed to filter out asbestos fibers and are effective to 99.97% of all particles 0.3 microns or greater.  They will also filter out viruses.

Glad you were able to get some good stone out of the block, it have lovely color.

Bob Johannes
The Amethyst Rose
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« Reply #39 on: January 06, 2016, 04:13:48 am »

Nephrite is problematic in definition (jadeite is not immune either). Most gemstones are minerals and as such are defined by their chemical composition, eg rubies being corundum with chromium as the colouring agent. Minerals have a specific chemical composition (with some variabilily where one element substitutes for anther in a series) that can be determined the XRD and other methods. Rocks are distinguished from minerals in that they are made up of a combination of minerals, this can be obvious in the case of granite where each mineral is present as discrete crystals, or as a mixture of minerals as is typical with serpentinite.

The problem with nephrite is that it is defined by the physical characteristics of the rock, specifically toughness due to felting of the crystals in the rock. Usually nephrite is defined as a combination of actinolite and tremolite where the crystals ave felted together. If not fully felted the rock will fall apart when cut. Actinolite and tremolite can exist together and not be nephrite if the felting is not present. Whether pure actinolite or tremolite can be nephrite has long been debated. This is further complicated by the fact that a rock can grade in and out of nephrite in a single piece.

If I understand Finegems argument correctly, he is stating that since nephrite does not have a specific chemical composition (is not a mineral) it does not exist, and points to the GIA's reluctance to identify nephrite as proof. That the mineral naming organisations do not recognise nephrite is not surprising as it is a not a mineral it is a rock.

The term jade was in common usage several thousand years before XRD was invented. It's generally accepted use is good enough for me, though I expect the arguments will rage forever.

Jadeite is sometimes referred to as the only 'true' jade (often by jadeite sellers) as it is an identified mineral with a specific chemical composition. However it is also problematic for two reasons, firstly the GIA in testing discovered that some gem quality jadeite was actually the related mineral omphacite, hence their inclusion of omphacite under the heading of "jade" (if they did not do this many of the certificates they previously issued would be invalid, plus gem quality jadeite and omphacite at least once cut can only be differentiated via XRD. Secondly, jadeite itself rarely occurs in pure form, jadeite rocks are commonly a mixture of jadeite, omphacite, other pyroxenes and other minerals such as feldspar and quartz. So a problem for jadeite is what percentage of jadeite is required to call a rock "jade", Google the technical papers on Turkish purple jadeite for examples, Guatemalan jadeite is also commonly a mix.

So for me, jade is by definition a historic term that refers to rocks that have a toughness that exceeds all other rocks (btw nephrite is tougher than jadeite due to the felting of the crystals, in jadeite the crystals are interlocking but not felted) therefore I am happy referring to nephrite and jadeite as jade.

David
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« Reply #40 on: January 06, 2016, 02:07:57 pm »

Thanks for posting southerly. This is probably the best explanation. The key is the felting which gives the rocks their toughness and ability to be carved into thin pieces and sculptures.

Of course this felting can't be quantified/qualified 100% and used to define which amphibole is "nephrite jade" and which is not "nephrite jade."

There is no scientific dividing line which defines jade by it's percent of felting.

At least not to my knowledge at this time.

BTW I still have your awesome quote on my website.

http://www.finegemdesigns.com/blackjadesprojectpage3.htm

:o)
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« Reply #41 on: January 06, 2016, 10:53:20 pm »

Edwards Black on a Case peanut finished yesterday - sold today.....



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« Reply #42 on: January 06, 2016, 11:31:14 pm »

Well done.

 dancer7
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« Reply #43 on: January 07, 2016, 12:10:10 am »

Great looking knife Michael.
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« Reply #44 on: January 07, 2016, 12:17:18 am »

BTW.. lapis lazuli is also a rock not a mineral, with variable composition, made up of lazurite, sodalite, calcite and pyrite, in varying concentrations which create the different grades of lapis and also suffers from the problem of when does the lazurite percentage become too low to call it lapis lazuli?
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« Reply #45 on: January 07, 2016, 06:34:59 am »

All this talk about black jade, makes me hungry to try another project in Black jade.
How does a Grimm sound? Any good designs out there I could hold on too?
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