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Every thing JADE and about Jade

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Author Topic: Every thing JADE and about Jade  (Read 2349 times)
wyrock
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« Reply #30 on: November 25, 2013, 08:00:26 am »

The rock shop in Buffalo closed a few years ago shortly after I started playing with rocks. The father died, the mother was 80s and the son seemed a little bit slow minded. I bought some things to help them out but there was just no traffic through the shop. The father was a jeweler and when he died that income ceased.

I got to know them and the next time I am over that way I want to see what they might still have. Their house is a ways behind the shop and I think the daughter helps to support them.

The shop in either Rochester or Daton was open, closed then open again but all he had/has is mineral and agate samples and dino stuff (a lot of coppies, teeth and skulls).

I do not know of any other. I went to the rock show in Cody a couple of years ago but was looking for mostly IDs. There were a lot of vendors there. I was at a vendors table getting IDs from him and a young guy walked up with an apple green stone in his fist (tight fist). He would not let go of it and the vendor had to ID it in the guys hand. It was a beautiful piece of apple green with no inclusions and was priced by the vendor high enough to make me suck in my breath. That is the only apple green that I have seen.

The nephrite that I have I pick up all over the place around here. The only way for me to be sure (fairly sure) that it is nephrite is by SG, break (almost impossible) and the look of it. I have gotten to the point now where I can pick up a stone and pretty much tell by the weight of it that it is nephrite or a very close cousin. I find some pieces that have a higher SG than nephrite but it does not look like jadeite which is a little heavier. There are so many nephrite/jade wanabees out there that sometimes it is hard to tell what you have picked up. nephrite is made up of actinolite and tremolite so some of what I have may be one or the other of those two.

Way too much guessing.
Jim
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Cowboy
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« Reply #31 on: November 25, 2013, 11:55:19 am »

Thanks Cowboy. I'll see if I can find any of those online.

This made me laugh inside!  Having set foot in all the shops I mentioned, and met the proprietors, I would be utterly dumbfounded to learn that any of them owns a computer, let alone operates a website.

The Torrington rock shop has one very nice chunk of jade that I'd like to own. It's not typical "apple" green, as it's about the same shade as the very palest green apple you'll ever see. It has some inclusions, but looks absolutely lovely anyway. A huge uniformly colored  block, probably ten pounds, cut on all sides but one, into a blocky rectangle, probably three inches thick and roughly 8 by 10 inches. They want every penny for it. I think the asking price on the tag is around $6000.

Oddly, I bought a very nice chunk of apple-ish jade from them a couple years ago, a nice 5 by 5 by 5 inch cube, for only $175. I thought it was a bargain, especially after I cut a few cabs and it came out looking like this:



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VegasJames
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« Reply #32 on: November 26, 2013, 11:22:38 pm »

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.
"

Yes, bamboo has the highest silica content of any plant.  It is 7 times higher in silica than horsetail grass, which is often claimed to be the highest silica source.

Another interesting fact is that the sap of bamboo will sometimes form opal referred to as vegetable opal.
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3rdRockFromTheFun
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« Reply #33 on: November 27, 2013, 01:41:58 am »

Beautiful cab there Cowboy. Thanks for the info and yah - I know; but maybe I'll find phone numbers at least. This is by no means urgent - if it takes a year I'm good (so many things going on and things I'm trying to work out lapidary-wise).
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southerly
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« Reply #34 on: December 26, 2013, 06:00:02 pm »

Here is some more jade samples.

The first two photos are from the same block of Tamworth nephrite, the first slab is cut across the grain, this has the better pattern but the edges crumbled in the saw and I am not sure it would stand up to carving or cutting. The second slab is cut with the grain, I used this to make the 501 I posted recently.
I had trouble with the pointy edges of the scales where they meet the bolster as the grain direction meant they had little support, luckily when the edge fell apart on the grinder it just missed the area I needed for the knife and I was able to move to sanding only on those edges.

The third photo is a bottroydal jade, the fibres are radiating and it splits really easily along the fibres.

The 4 & 5 photos are of a piece of jade I trimmed carelessly, you can see the circular shatters is caused as it lifted the fibres. The second shot on the side shows how the fibres were deformed.

The last photo is of a chunk of jade showing the shistosity that some jades have. This one will be hard to cut as it is very layered.

David



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southerly
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« Reply #35 on: December 26, 2013, 06:11:34 pm »

Not all nephrite jade has well defined layering and direction, in fact the best carving nephrite has very finely compressed fibres and the grain is very hard to determine.

This photo is of a very thin slab of very well compacted nephrite jade from Tamworth, the colour only shows in thin section. The slab is wedge shaped about 4mm at the thickest end and 0.5mm at the thinest, even at 0.5mm it is solid and cannot be broken by applying force by hand, it also has a superb 'jade' ring. There is no easy why to tell the direction of the grain in this jade as each cut face is shiny smooth. It needs to be very thin to show off the jade, would be excellent at plectrum material.


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JoJo
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« Reply #36 on: January 06, 2015, 07:13:43 am »

I have some nice pieces of jade I picked at Jade Cove.  It is already really nicely shaped.  I feel kinda naive here, but can I just put it in my rotary tumbler to finish the polish?  Most of it already seems naturally polished.  But should  I tumble it more to put a high gloss on it, or leave it natural?  At some point I would like to make some pendants. 
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« Reply #37 on: January 06, 2015, 10:17:28 am »

So...  is the apple green worth more?
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Michael S Hoover - Redrummd
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« Reply #38 on: January 06, 2015, 08:53:06 pm »

Apple green is the most valuable color in China and most of the world but white in Korea.  So, it is somewhat "cultural" in assessing value.  I prefer the bright "apple" green as it shows best in low light and normal work and shopping locations.
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snowmom
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« Reply #39 on: February 11, 2015, 03:38:52 am »

As nephrite jade is the name given to a actinolite/tremolite mix where the crystals are felted together and often includes or grades into other minerals it is highly variable in the tightness of the felting, the grain size of the crystals and the direction of the grain and impurities. Therefore every piece of jade is different and as Michael points out often varies in the same boulder.

To further complicate things further nephrite is an alteration product of other minerals and grades between them in a metamorphic melange. It is these properties that make it both very tough and able to take fine carving and a challenge to cut and polish. There is probably more written about selecting, cutting and polishing jade than perhaps any other lapidary material.

It is just this variability that is throwing me in learning about jade. I joined the fourm because it is evident we have several Jade experts available and I want to learn about jade. My interest started when I learned that Jade had been found in Michigan. There was an article in a rock and gem magazine and it seems it was largely ignored. The discoverer was  a Dr Julian Greenlee, who was a science teacher among many other interests and abilities.  There was mention of his jade finds being verified by several universities and the Smithsonian, and I found several articles online, one which claimed he had found nephrite AND jadeite.   Flash forward to a couple of weeks ago when a rock I had found was examined by a geologist at University of Tennesee and thought it might be jadeite- tests pending.  Here is my problem. All Jade found in locations here are most likely glacial transports. They are extremely varied and most have inclusions. Not one suspect I have picked up has had any translucence.  I have heard Edwards jade is not translucent, and this stuff resembles the photos I have seen of it.  I have done test polish windows on many pieces looking for "jade milk" and many seem to produce something like that, but having no experience with jade before I can not confirm this is what the stuff is.
Can the stuff I am finding be nephrite and not be jade?


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Debbie K
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« Reply #40 on: February 11, 2015, 08:15:49 am »

I'm not the foremost expert on jade on this forum, but I do know quite a bit about it.

One of the easiest tests you can preform is determining the suspect rock's specific gravity. This is done by determining the stone's weight, then the stone's weight in water. You subtract the water weight from the air weight, and then divide the air weight by the difference.

In other words,

Air Weight
(Air Weight - Water Weight)           = Specific Gravity

There are many ways to rig up ways to do this. Do a youtube search, if you come up empty-handed I'll try to find you a link.

Serpentine (s.g. approx. 2.57) and many other jade lookalikes will usually be considerable lighter-weight. Jadeite (s.g. approx., 3.34)  is even heavier than nephrite (s.g. approx. 2.95).

Not all jade is translucent. The black jade from Australia will not allow any light to pass thru. Some of the Alaskan and Wyoming and even the New Mexican jade are extremely opaque. You need an edge or slice to be able to determine if it has any translucency. If you can find an edge, put a flashlight behind it and see if any light passes through.

I shared your frustration about understanding jade and jadeite. About ten years ago I went to a talk given by a Chinese carving manufacturer and inquired how you determine if something was jade. His roundabout answer was, whatever we say it is. I had the good fortune to meet a lady who was studying to be GIA accredited; and she and I went through a huge education regarding what makes something "jade". I have also had the opportunity to see and handle jade from all over the world, and it makes a huge difference to have that experience. Just stick with it, and you will learn.

Debbie K
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Michael S Hoover - Redrummd
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« Reply #41 on: February 11, 2015, 09:46:54 am »

The photos do show what looks to be Jade.  That black colored Jade is often found on the Washington coast beaches and is referred to as beach Jade here.   
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snowmom
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« Reply #42 on: February 11, 2015, 04:10:00 pm »

Debbie K and Michael H, thanks for the input, that is encouraging. I have sent samples to several people from another forum, and some thought maybe jade, some thought  other things. But what I find is so variable that each piece I sent to somebody might have been different.  Specific gravity tests show the stuff is right in the jade ballpark or it is heavier/more dense than jade. I am still a beginner and do not have all the right equipment (saw and scientific scales) to do tests on many of these large pieces. There are plans to aquire them in the future. I'll get there!
 Jade as a subject is fascinating and I know it is complicated.  I have read all back posts on any forum I can find regarding jade, looked at countless photos, annoy people with questions, and hope to continue to learn. Thank you!
Deb in Michigan. 
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Debbie K
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« Reply #43 on: February 11, 2015, 05:04:15 pm »

Deb:

If you'd like, my friend (the GG, Graduate Gemologist) and I could get an RI on a small sample. If you have a small chip I could polish it and get a spot reading which would tell us a little more than just the specific gravity.

Nephrite and Jadeite both are composite type stones, they both have varying degrees of different elements in them and my understanding is that the elements need to conform to certain defined ratios to be considered jade. With this in mind, it may behoove you to send some to a gem lab and have a chemical analysis done, something well beyond my capabilities.

Frank and Mick are both real experts in finding jade in the wild, and I'm really hoping that they will weigh in as they have so much knowledge on the subject.

I'm excited today because a friend brought me back some Washington blue jade from Tucson; it makes my Guatemalan blue look very bad in comparison. Michael Hoover, who answered your post also, has done some beautiful knife scales out of the same type of blue jade, I forget what the website was. I'm trying to figure out what I want to carve out of it.

Debbie K

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« Reply #44 on: February 11, 2015, 11:42:56 pm »

Debbie, are we gonna get to see a some photos of it?
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