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Hairlike Gold inclusions in Quartz??
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Duncan Miller




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PostPosted: Jun 25, 2018 05:24    Post subject: Re: Hairlike Gold inclusions in Quartz??  

zbhjzm wrote:
SEM/EDS analysis requires the specimen to have a flat surface
Ideally yes, but not in practice if you only want an approximate analysis. The operator probably can tilt the stage so that an exposed fibre end is more or less perpendicular to the electron beam. It may be worth asking. The curved surface of a cabochon will not get in the way of the emitted X-rays, which often is the problem with specimens that are not flat. I know, because in the past I did lots of SEM-EDS analyses on mineral fragments and small archaeological specimens that could not be polished flat.
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PostPosted: Jun 25, 2018 05:57    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Duncan Miller wrote:
zbhjzm wrote:
SEM/EDS analysis requires the specimen to have a flat surface
Ideally yes, but not in practice if you only want an approximate analysis. The operator probably can tilt the stage so that an exposed fibre end is more or less perpendicular to the electron beam. It may be worth asking. The curved surface of a cabochon will not get in the way of the emitted X-rays, which often is the problem with specimens that are not flat. I know, because in the past I did lots of SEM-EDS analyses on mineral fragments and small archaeological specimens that could not be polished flat.

I‘ll ask them if they can do that, thank you.
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PostPosted: Jun 25, 2018 07:00    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Duncan Miller wrote:
zbhjzm wrote:
SEM/EDS analysis requires the specimen to have a flat surface
Ideally yes, but not in practice if you only want an approximate analysis. The operator probably can tilt the stage so that an exposed fibre end is more or less perpendicular to the electron beam. It may be worth asking. The curved surface of a cabochon will not get in the way of the emitted X-rays, which often is the problem with specimens that are not flat. I know, because in the past I did lots of SEM-EDS analyses on mineral fragments and small archaeological specimens that could not be polished flat.

I asked them and they said yes, so I'll send them the specimen tomorrow.
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zbhjzm




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PostPosted: Jun 28, 2018 05:06    Post subject: Re: Hairlike Gold inclusions in Quartz??  

The SEM-EDS analysis has failed...
Because the fiber ends are too small and almost indistinguishable under electron microscope,the operator tried many times but just couldn't find the right spot, the test results were always the same , mostly SiO2 and a trace of Mg...
Maybe I should give up....



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zbhjzm




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PostPosted: Jul 03, 2018 06:57    Post subject: Re: Hairlike Gold inclusions in Quartz??  

I marked the spots out with scotch tape and did the analysis again ,and the result suggests that the inclusions are Gold.
( some of the Au in the results are from the Gold coating they did before the analysis)



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Duncan Miller




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PostPosted: Jul 03, 2018 13:40    Post subject: Re: Hairlike Gold inclusions in Quartz??  

zbhjzm wrote:
I marked the spots out with scotch tape and did the analysis again ,and the result suggests that the inclusions are Gold.
( some of the Au in the results are from the Gold coating they did before the analysis)

That is why I suggested they carbon coat your specimen. You don't gold coat an SEM-EDS specimen you suspect may contain gold!

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PostPosted: Jul 03, 2018 19:07    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Duncan Miller wrote:
zbhjzm wrote:
I marked the spots out with scotch tape and did the analysis again ,and the result suggests that the inclusions are Gold.
( some of the Au in the results are from the Gold coating they did before the analysis)

That is why I suggested they carbon coat your specimen. You don't gold coat an SEM-EDS specimen you suspect may contain gold!

I know , but they can not do carbon coating, I might have to find somewhere else to do it. But I also had another specimen with Cannizzarite inclusion tested, and the result shows that the gold coating is only about 7.9%.



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PostPosted: Jul 04, 2018 09:42    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Clear pics of the results.(Gold Quartz and Cannizzarite)
Maybe the gold coating has some effect on the results, but if the inclusions were not gold, they should have been detected, so I think they are indeed gold.



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PostPosted: Jul 04, 2018 10:20    Post subject: Re: Hairlike Gold inclusions in Quartz??  

This does look convincing, even if less than analytically ideal. I am glad you have persisted.
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PostPosted: Jul 04, 2018 20:38    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Duncan Miller wrote:
This does look convincing, even if less than analytically ideal. I am glad you have persisted.

Thank you very much.
Filiformed Gold (if they are) in quartz is extremely odd.
So, obviously, those specimens need further study. I can't do this on my own, I have to find a research institute to work with.
I've already contacted GIA, just haven't gotten the reply yet.
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Peter Lemkin




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PostPosted: Jul 04, 2018 22:54    Post subject: Re: Hairlike Gold inclusions in Quartz??  

zbhjzm wrote:
Duncan Miller wrote:
This does look convincing, even if less than analytically ideal. I am glad you have persisted.

Thank you very much.
Filiformed Gold(if they are) in quartz is extremely odd.
So, obviously, those specimens need further study. I'cant do this on my own, I have to find a research institute to work with.
I've already contacted GIA, just haven't got the reply yet.


In the book I mentioned, above, by Hrsyl et al. there are a few examples of gold in quartz - but it is RARE! That three volume book put out by the GIA will tell you more about where it has been found and just how rare, etc. They also know how to test for it. Would be interesting to know where in Brazil these are from.....
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PostPosted: Jul 04, 2018 23:27    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Peter Lemkin wrote:
zbhjzm wrote:
Duncan Miller wrote:
This does look convincing, even if less than analytically ideal. I am glad you have persisted.

Thank you very much.
Filiformed Gold (if they are) in quartz is extremely odd.
So, obviously, those specimens need further study. I can't do this on my own, I have to find a research institute to work with.
I've already contacted GIA, just haven't gotten the reply yet.


In the book I mentioned, above, by Hrsyl et al. there are a few examples of gold in quartz - but it is RARE! That three volume book put out by the GIA will tell you more about where it has been found and just how rare, etc. They also know how to test for it. Would be interesting to know where in Brazil these are from.....

Thank you, but since the seller got the raw stones from someone else, and he might have gotten the stones from someone else too, the origin of the stones is almost impossible to trace...
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Diamond




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PostPosted: Jul 05, 2018 05:39    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Wow you found god's beard :D nice item!
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PostPosted: Jul 05, 2018 07:29    Post subject: Re: Hairlike Gold inclusions in Quartz??  

Diamond wrote:
Wow you found god's beard :D nice item!

Oh yes, thank you~
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