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Post by HankRocks on Sept 2, 2020 20:13:31 GMT -5
Another piece from the acquired stash. Someone thought Jade, I am not so sure.  IMG_2003 by Findrocks, on Flickr It's attractive backlit. Not sure what I will do with it.  IMG_2004 by Findrocks, on Flickr |
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Jade ?
Sept 2, 2020 20:22:52 GMT -5
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Post by mohs on Sept 2, 2020 20:22:52 GMT -5
whatever it be Hank that green is a go  |
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Jade ?
Sept 2, 2020 20:33:20 GMT -5
Post by taylor on Sept 2, 2020 20:33:20 GMT -5
I think that the rind screams jade. Very nice slab!
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Jade ?
Sept 2, 2020 21:34:31 GMT -5
Post by pauls on Sept 2, 2020 21:34:31 GMT -5
I think that the rind screams jade. Very nice slab! I agree, sure looks like Jade. |
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polaszko
having dreams about rocks
Member since August 2020
Posts: 58
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Jade ?
Sept 3, 2020 14:45:12 GMT -5
Post by polaszko on Sept 3, 2020 14:45:12 GMT -5
It can also be nephrite - it's very familiar to jade and even sometimes words "jade" and "nephrite" are used at the same time for one species, of course it's incorrect advertising slogans, but they show how familiar those rocks are.
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Jade ?
Sept 5, 2020 21:51:10 GMT -5
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Post by stephan on Sept 5, 2020 21:51:10 GMT -5
It can also be nephrite - it's very familiar to jade and even sometimes words "jade" and "nephrite" are used at the same time for one species, of course it's incorrect advertising slogans, but they show how familiar those rocks are. Nephrite IS a form of jade. I am betting it is nephrite, and I love the white streaks. Those are, incidentally, lacking iron, and higher in magnesium. The nephrite chemical formula is Ca2(Mg,Fe)5Si8O22(OH)2. The ratio of the mixture of Ca and Fe determines the color. All Mg is white. All Fe is “black” (actually very dark green). The apple to forest green color we usually see is an almost even mix. |
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Post by stephan on Sept 5, 2020 22:21:20 GMT -5
Just an FYI on the formation of jade, it is metamorphic, and formed by subduction. Often it is formed where continental plates meet oceanic plates (current or former), and the sea-muck is subducted. Short story: how deep it goes determines whether serpentine, nephrite jade or jadeite is formed. Often one gets rocks that are "transitional" and don't fit neatly into one of those categories. I've worked material that was sold as (and by all appearances was) nephrite, but was much softer and produced a serpentine-like foamy swarf when worked. The polish was in-between the two. It gets a lot more complicated: blueschist, greenschist, glaucophane, garnet, eclogite, omphacite and epidote are all related (and can be indicators for what species is found). There is an excellent book ("California Jade: The Geologic Story of Nature's Masterpiece" by Donald Dupras ) that explains this in-depth. |
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Post by stephan on Sept 5, 2020 22:38:27 GMT -5
Ok, one more comment  : if you have nephrite that is still closer to serpentine, there is a chance that the white veins are talc (hydrated serpentine), but it will be pretty easy to tell, as talc is soft and crumbly. You can often tell by flexing the slab. Talc will often snap. Jade, however, is one of the toughest rocks an will not. BTW, toughness is different than hardness. It rates resistance to fracture, while hardness rates resistance to scratching. Jade is tougher than diamond, with nephrite being tougher (but softer) than jadeite. |
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RWA3006
Cave Dweller 
Member since March 2009
Posts: 4,653 
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Jade ?
Sept 6, 2020 9:06:40 GMT -5
Post by RWA3006 on Sept 6, 2020 9:06:40 GMT -5
I'd say nephrite because of the rind. My experience with nephrite I've collected in Wyoming matches Stephan's comments. A lot of jade is "transitional."
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Post by stephan on Sept 6, 2020 10:29:16 GMT -5
A few more comments:
Looking at the pic again, and seeing the translucence of the white, white jade is more likely than talc.
Btw, pure white pieces of nephrite are referred to as mutton fat jade, and are highly prized by Chinese artisans (especially carvers).
Given the previously given information, be aware that nephrite has a fibrous structure, like serpentine. Sometimes that structure makes getting a high polish difficult. To combat this, I usually let the last step (the last wheel and the leather with 100k grit) run dry, so that they get hot. Without the water, there will be airbone fibrous dust. If you take this step, be aware of the potential hazard, and decide for yourself whether or not respiratory protection is warranted. For myself, it’s less than 5 minutes, and a well-ventilated space.
Jadeite, on the other hand, is granular in structure.
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Jade ?
Sept 6, 2020 10:53:10 GMT -5
Post by drocknut on Sept 6, 2020 10:53:10 GMT -5
Pretty cool slab. Looks like Jade to my untrained eye. Looks like you got a lot of feedback on it so that's great. I didn't know much about Jade but now I do ;-)
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polaszko
having dreams about rocks
Member since August 2020
Posts: 58
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Post by polaszko on Sept 6, 2020 12:10:43 GMT -5
It can also be nephrite - it's very familiar to jade and even sometimes words "jade" and "nephrite" are used at the same time for one species, of course it's incorrect advertising slogans, but they show how familiar those rocks are. Nephrite IS a form of jade. I am betting it is nephrite, and I love the white streaks. Those are, incidentally, lacking iron, and higher in magnesium. The nephrite chemical formula is Ca2(Mg,Fe)5Si8O22(OH)2. The ratio of the mixture of Ca and Fe determines the color. All Mg is white. All Fe is “black” (actually very dark green). The apple to forest green color we usually see is an almost even mix. Ohh I mistook jade with jadeite... in my language these names aren't that familiar. |
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Post by HankRocks on Sept 6, 2020 12:13:16 GMT -5
Thanks for all the comments. stephan, thanks for the lesson. Still not sure I could pass any future identification tests!! I have more of this material(or very similar) both large pieces and slabs. One piece is labeled Wyoming Jade, but is light colored. If I have time I will pull them out from where they are buried and post some pictures. Not sure what I will do with this polished piece, probably end up selling it at a Show eventually. I like to be able to identify the pieces I sell even if I use the generic term, "Agate" or "Jasper". for a few pieces. Definitely not willing to intentionally misrepresent anything I sell. See enough of that on Ebay. I had a couple of pendants out at one Shows that had a Jade-ish look to them. The lady who was interested in both asked if they were Jade. Told her I could not honestly call them Jade, she bought both because she liked the color. Henry |
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Jade ?
Sept 6, 2020 12:34:29 GMT -5
Post by stephan on Sept 6, 2020 12:34:29 GMT -5
Thanks for all the comments. stephan , thanks for the lesson. Still not sure I could pass any future identification tests!! I have more of this material(or very similar) both large pieces and slabs. One piece is labeled Wyoming Jade, but is light colored. If I have time I will pull them out from where they are buried and post some pictures. Not sure what I will do with this polished piece, probably end up selling it at a Show eventually. I like to be able to identify the pieces I sell even if I use the generic term, "Agate" or "Jasper". for a few pieces. Definitely not willing to intentionally misrepresent anything I sell. See enough of that on Ebay. I had a couple of pendants out at one Shows that had a Jade-ish look to them. The lady who was interested in both asked if they were Jade. Told her I could not honestly call them Jade, she bought both because she liked the color. Henry I applaud your honesty. All I can say is that it looks a lot like nephrite jade. Impossible to tell for sure from a picture, without physically handling it. That said, the white streaks do point tentatively toward Wyoming material. In California, it is less common, and, when present, more likely to be talc. A lot of people thing of Wyoming jade as being apple green, but there is certainly variation. The rind looks Wyoming-like, too. A few things you could do to test: - Specific gravity: if you have access to a precise scale and volumetric device, weigh it and measure water-displacement. SG should be 2.90-3.03. You can rule out other green minerals (this would be the most reliable test) - scratch test: if harder than steel you can rule out serpentine. - hand polishing (a cab-sized piece): this is hard to describe, but jade behaves in certain ways that are different than other stones (a slightly soapy feel and swarf, how well it polishes at different steps, the way it "sings" on the hard wheels. I have no experience tumbling or polishing slabs, so I can't help there. - "Chime test": strike a slab with a hard object. Nephrite will sound musical. - Jade should be cool to the touch Hope this helps |
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RWA3006
Cave Dweller
Member since March 2009
Posts: 4,653
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Post by RWA3006 on Sept 6, 2020 14:11:54 GMT -5
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Post by mohs on Sept 6, 2020 14:47:53 GMT -5
this could be might be not sure  any other ideas ? thanks ~mohs |
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Jade ?
Sept 6, 2020 22:21:50 GMT -5
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Post by stephan on Sept 6, 2020 22:21:50 GMT -5
Don’t know much about purple jade, other than that it is from Bursa, Turkey. It looks legit, with the caveat that it’s hard to tell from a photo. I haven’t heard much about there being counterfeit material, which is kind of surprising.
There does not appear to be a consensus as to whether it is “pure” jadeite, or a rock.
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Jade ?
Sept 6, 2020 23:22:44 GMT -5
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Post by mohs on Sept 6, 2020 23:22:44 GMT -5
Thanks for the information Stephan
I bought that stone when I first got into the hobby
As a purplish jade
from a vendor at the Flagg Rock & Mineral show.
Long time ago now
I recall the vendor was very informative
Now there may be some cognitive bias from your information
But I do believe the vendor was saying something about the material being from that area.
I only bought a small slab. About 2” x 1" x 1/4"
Probably paid 20.00 dollars Maybe more.
Anyway he was telling me that jade likes heat in the polishing stage to get it to shine.
So that my goal.
The finish on it now is o.k.-- but really-
its not that much better than the raw slab itself.
I’d like to improve on that. Yet, not really sure what I can expect ?
So I just keep polishing it on leather w/14,000 diamond/
Although I haven’t got it hot yet.
I shy away from that for obvious reasons.
Really appreciate the chiming in
Ed
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Jade ?
Sept 7, 2020 1:13:06 GMT -5
mohs likes this
Post by stephan on Sept 7, 2020 1:13:06 GMT -5
Anyway he was telling me that jade likes heat in the polishing stage to get it to shine. So that my goal. The finish on it now is o.k.-- but really- its not that much better than the raw slab itself. I’d like to improve on that. Yet, not really sure what I can expect ? So I just keep polishing it on leather w/14,000 diamond/ Although I haven’t got it hot yet. I shy away from that for obvious reasons. I suppose we could use that as another test. If it’s jade, heat won’t make it shatter. As for polishing at 14k, some jade I’ve worked didn’t progress past the satin finish until 50k or 100k. Some not even then. At least jadeite won’t orange peel on you. I do understand the hesitation when working with a scarce material. Also, it looks like your pendant is made of two glued halves. I’ve never subjected cyanoacrylate to heat (other than what connects the cab to the nail), so I don’t know for sure how it would behave. That said, I haven’t launched any cabs, due to glue failure. To get it hot, you will want to ‘dop’ with superglue (actual dop wax may give out on you — I guess I answered my own question), and then you’ll have to get it off the nail without separating the halves.... Good luck. |
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quartzilla
Cave Dweller
Member since April 2020
Posts: 1,242
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Jade ?
Sept 7, 2020 11:22:16 GMT -5
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Post by quartzilla on Sept 7, 2020 11:22:16 GMT -5
I’ve always understood jade, whether nephrite or jadeite, to be one of the hardest stones to identify. This thread helps explain why. Thanks Stephan.
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: if you have nephrite that is still closer to serpentine, there is a chance that the white veins are talc (hydrated serpentine), but it will be pretty easy to tell, as talc is soft and crumbly. You can often tell by flexing the slab. Talc will often snap. Jade, however, is one of the toughest rocks an will not. BTW, toughness is different than hardness. It rates resistance to fracture, while hardness rates resistance to scratching. Jade is tougher than diamond, with nephrite being tougher (but softer) than jadeite.
