CIBJO releases Gemmological Special Report: considers process of separating measurable facts from opinion; See Gemological Articles below.
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Fri Nov 15, 2019 6:41 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 122 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 9  Next
Author Message
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sat Jun 16, 2018 11:03 pm 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
Barbra Voltaire wrote:

I confirmed that they are quartz by using a polariscope. It is the first thing I will do, if I got something suspicious.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 5:07 am 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
Strange stuffs continue to appear...
This one really looks like silver foil wire(with a darker color)in glass.
But it has also been confirmed to be genuine quartz by polariscope...


Attachments:
1.JPG
1.JPG [ 68.09 KiB | Viewed 1003 times ]
2.JPG
2.JPG [ 61.23 KiB | Viewed 1003 times ]
3.JPG
3.JPG [ 36.29 KiB | Viewed 1003 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 5:08 am 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
More pics:


Attachments:
4.JPG
4.JPG [ 40.55 KiB | Viewed 1003 times ]
5.JPG
5.JPG [ 33.75 KiB | Viewed 1003 times ]
6.JPG
6.JPG [ 36.05 KiB | Viewed 1003 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 5:08 am 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
More pics:


Attachments:
7.JPG
7.JPG [ 43.81 KiB | Viewed 1003 times ]
8.JPG
8.JPG [ 45.03 KiB | Viewed 1003 times ]
9.JPG
9.JPG [ 47.02 KiB | Viewed 1003 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 10:55 am 
Offline
Gemology Online Veteran

Joined: Thu May 12, 2016 2:18 am
Posts: 645
How does the polariscope prove that it is quartz. Can you post a picture of the test?


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 12:24 pm 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
The pic blow shows the difference between Quartz and Glass under polariscope.
But the polariscope can only confirm that it is genuine quartz, as the quartz is so clear,there is no way to tell if it is natural or lab-grown.
So, there sill the possibility that it could be a lab-grown quartz.


Attachments:
p.jpg
p.jpg [ 62.35 KiB | Viewed 987 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 4:44 pm 
Offline
Gemology Online Veteran

Joined: Mon May 26, 2014 9:42 pm
Posts: 804
I was just wondering how difficult it would be to fake this -- inserting quartz, filling the cracks with glass or something. I am not saying it *IS* - I just would like to have a lab actually look at these weird things and decide.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 5:03 pm 
Offline
Gemology Online Veteran

Joined: Thu May 12, 2016 2:18 am
Posts: 645
I suspected that this might be your answer to my question. The test you posted doesn't prove that the material is quartz. If in fact you are getting the blink, it only proves that the material is doubly refractive. Yes, quartz is double refractive, as are many other colorless materials. Also, there are things like snake lines, and anomalous double refraction that will easily fool those not well experienced in the use of a polariscope.

There is one polariscope test that would be definitive for quartz. That is the presence of the uniaxial "Bulls eye" optic figure on the C axis.

Here is a great paper on this:

http://www.minsocam.org/msa/OpenAccess_ ... educed.pdf

This U Tube video will be easier to understand and has a nice discussion just after 10 minutes on optic figures an quartz.

https://www.youtube.com/watch?v=4MtKkyKaX_0


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 8:45 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19887
Location: San Francisco
I suspect, as does Steve, you may be seeing anomalous double refraction (ADR), zbhjzm, which mocks double refraction.

Steve has supplied some informative links for you.

Acicular gold does not exist in nature. But acicular gold foil clearly exists in Taiwan.

The ability to incorporate gold into glass has been well documented since ancient Roman times.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 10:38 pm 
Offline
Valued Contributor

Joined: Fri Jun 25, 2010 12:04 am
Posts: 147
Location: Idaho
Nice round bubble inclusions in picture 3.jpg

I would be checking for hardness, flow structures, etc. to make sure it is quartz.

_________________
Lapidarist by Love
Goldsmith by Necessity

Facetron
GemCad/GemRay
Matrix 8/Rhino 5
REVO A
EnvisionTEC Micro
Indutherm MC-15


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 10:45 pm 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
I don't thinks those specimens are glass not only because the polariscope testing, but also because they all hard enough to scratch glass. But the only way to get a definite answer is to send them to a lab for analysis. Finding a lab might be hard for me ,but I'll try.


Last edited by zbhjzm on Sun Jun 17, 2018 11:38 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 10:58 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 19887
Location: San Francisco
Send a couple to me. No charge.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 11:03 pm 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
abeck wrote:
Nice round bubble inclusions in picture 3.jpg

I would be checking for hardness, flow structures, etc. to make sure it is quartz.

Some of the bubbles are caused by glue which they introduced into the quartz before the cutting and polishing process.
The raw stones are full of fissures and cavities, so the reason why the glue are there is to protect the stones from cracking apart during the cutting and polishing process.
I hate glue in quartz, I would rather they give me the raw stones.But I got no choice ,it has already been down.
But, glue in quartz also proved that the stones are natural , lab-grown quartz or glass do not need to be glued.
Also, the glue only in the fissures and cavities , the haire-like inclusions with exposed ends on the surface are surrounded by quartz, because I can prove that by a needle.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Sun Jun 17, 2018 11:10 pm 
Offline
Valued Contributor

Joined: Fri Oct 06, 2017 6:12 am
Posts: 135
Barbra Voltaire wrote:
Send a couple to me. No charge.

Thank you, but I live in China, sending something overseas is also very costly.
I'll try to find a lab in my city first, If the testing is not too costly, I'll do it.


Top
 Profile  
Reply with quote  
 Post subject: Re: Hairlike Gold inclusions in Quartz??
PostPosted: Mon Jun 18, 2018 8:19 am 
Offline
Gold Member
User avatar

Joined: Mon Apr 16, 2007 12:05 am
Posts: 1462
1bwana1 wrote:

There is one polariscope test that would be definitive for quartz. That is the presence of the uniaxial "Bulls eye" optic figure on the C axis.

Here is a great paper on this:

http://www.minsocam.org/msa/OpenAccess_ ... educed.pdf

This U Tube video will be easier to understand and has a nice discussion just after 10 minutes on optic figures an quartz.

https://www.youtube.com/watch?v=4MtKkyKaX_0


The use of a conoscope with a polariscope is also described in The Gemology Project.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 122 posts ]  Go to page Previous  1, 2, 3, 4, 5 ... 9  Next

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock