January 24 Through February 4—TUCSON, ARIZONA: Annual show
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Thu Mar 28, 2024 11:41 am

All times are UTC - 4 hours




Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3
Author Message
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sat Apr 15, 2023 11:12 am 
Offline
Gold Member

Joined: Thu May 12, 2016 2:18 am
Posts: 1542
GIA is not going to mis-identify quartz. They will have used a number of tools to do the idetification. It will have been agreed upon by at minimum two Gemoligist that do not know what the other's results were.

Their tests used will most likely include a scan with a Raman Spectrometer. If a good quality Raman scan is acheived the result is considered unique for all molecules, and definative. The Raman would have difinatively identified the SiO2 moloclule in your stone. This results in both a definative mineral identification, but also the very chemical evaluation you keep asking for.

Stephen, Barbara, and I, among others on this site own, and frequently use Raman Spectroscopes in our work. Our Raman Specrometers use quartz, and diamond as the calibration minerals for the machines. Our machines will not miss on quartz. Barbara has generously offered you to stop by and watch her test your stones. She will run a Raman test for you I am sure.l take only minutes.

The test that will provide a full qualitative and quantitative chemical breakdown of your stone will be a Laser Abligation Spectrometer. This is not a trivial machine, or test. It vaporizes some of the stones material witha lasar. This vapor is then sucked into a plasma chamber, a spectro anaysis performed. this results in the identification of any element in the periodic table, and mor eimpresively it's quantity. This test must be done by a highly trained and qualified operator, on this very expensive machine. It is usually reserved for very consequential researc or origin studies. I am not surprised that GIA and the Universities will not do this for such a simple ID as Quartz.


By the way Stephen, Barbara, and I, are all Degree holding Geologists, and Gemologist, with decades of experience doing gemstone and mineral identifications. This is way beyond what you will find in a retail jewelry shop, or even a lab tech in a Gemmological Institution.

The answers and proofs that you seek have been offered to you. Why not take advantage of this and learn something at the same time?


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sat Apr 15, 2023 11:59 am 
Offline
Established Member

Joined: Thu Mar 23, 2023 5:46 am
Posts: 19
Stephen Challener wrote:
Incidentally I'm curious where you read about 'bethenine' or 'benthenine'. There's no mineral by that name--nepheline maybe?



I was quite confused for a minute also trying to figure out if perhaps I was studying made up minerals in my sleep! No, it's a mistype on the keyboard between B and N, lol. yes, nepheline!


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sat Apr 15, 2023 4:32 pm 
Offline
Gold Member
User avatar

Joined: Tue Apr 05, 2016 7:58 pm
Posts: 1424
Location: San Marcos, CA
GemmyFarmMom wrote:
If GIA is in fact wrong, then there you have it.

You may be unhappy that the GIA inherently made a mistake on the report calling it an Oval verses Rectangular but that does not make the call an error. Simply point it out to them and I am quite sure they will replace that report.
Our business has submitted stones thru the GIA for many years and errors happen, as we have the experience to know simple entry errors and sometimes apparent potential testing calls, they are still one of the foremost authorities in the industry. It is easy to understand your wondering well if that is wrong then maybe the call is. But agreed not likely that the call of quartz is. SR/DR, SG, RI tests are all that is needed in most cases, these 15-20k testing instruments are not likely to mistake quartz.

_________________
The Gem Garden
San Marcos, CA


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sat Apr 15, 2023 10:42 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
Reading your post thoroughly, GemmyFarmMom, I find a lot of mineralogical misunderstanding.
That being said, call the GIA lab and inform them that they made a mistake on the shape of the quartz. Chances are good, they will issue you a new report.

Quartz is a mineral having a composition of SiO2. There are a myriad of additional trace elements which can incorporate themselves into the quartz which cause color and other optical phenomenon. Milky quartz is the most common variety of crystalline quartz. The white color is caused by minute fluid inclusions of gas, liquid, or both, trapped during crystal formation, making it of little value for optical and quality gemstone applications. As Stephen mentioned, major gem labs will; use sophisticated spectrographic instrumentation for stone ID. A Raman spectrum is routinely the first step. If a Raman scan identifies an unknown as quartz.....case closed.

Feldspar is the name of a very large group of rock-forming silicate minerals that make up over 50% of Earth's crust. Feldspars will have the same arrangement of atoms and one basic chemical formula: X(Al,Si)4O8, where X stands for Na, K, or Ca. Ramans are also essential for accurately separating members of the Feldspar Group into minerals.
Plagioclase feldspars :
Albite
Oligoclase
Andesine
Labradorite
Bytownite
Anorthite
Orthoclase Feldspars:
Microcline
Sanidine
Orthoclase



"Moonstone" is NOT a mineralogically recognized term. It is a trade name which has been used to describe minerals (often varieties of feldspar but not exclusively) displaying adularescence.
Here is a link to an older thread on the causes of adularescence in feldspar:
https://www.gemologyonline.com/Forum/ph ... =6&t=13834


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sun Apr 16, 2023 7:15 am 
Offline
Established Member

Joined: Thu Mar 23, 2023 5:46 am
Posts: 19
It would seem Raman scopes are vastly out of my budget, and while I am trying to locate someone close by that I can take them to and perform this test and have them explain the results, it still would be helpful to understand what additional minute chemicals are involved in changing these from a normal "rock crystal quartz" to a milky quartz. I am curious (again, not having first hand knowledge on how a raman works and differentiates various chemicals), that since the chemical formula for quartz and milky quartz is the same, how do they conclude a stone is milky or common rock quartz?

I could understand that perhaps milky (as well as rose quartz) would contain additional impurities, but these would be found by use of complete chemical analysis, correct? And not through a Raman?


On a side note, in theory, could I on my own end, end this debate once and for all using a short wave UV lamp? From what I have researched, quartz, IF it glows under short wave UV light, it glows a yellow green, while most of the feldspar varities will glow a pink/red/orange red color or blue: http://www.fluomin.org/uk/fiche.php?id= ... e=feldspar depending on which variety. You can type the variety into the search box and pull up that mineral.

I have also read that certain minerals can only be seen with long exposure photos. I'm not sure if that applies to feldspar or quartz, but any experience you have with either under UV light would be helpful.

I might try the UV test, I did find a budget friendly shortwave lamp with great reviews online, so it would be worth my investment. Unless you feel the results might still be conflicting, then please let me know and why.

Thankyou


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sun Apr 16, 2023 10:05 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
The GIA does not teach the use of Raman, FTIR or LIBS spectroscopes in their courses, nor offer them for sale.
But they are available and essential in their labs for research and identification. More sophisticated Laser Induced Breakdown Spectroscopy (LIBS) is available through Caltech in Pasadena..

Gemstones can be positively identified using standard gemological tools. This is what is currently taught with the GIA, FGA, AIGS and FGG.
Training is essential.

Breaking down the chemicals present in minerals (gemstones are minerals) has been successfully done for us already. This is not new science or technology.
-Georgius Agricola is considered the "Father of Mineralogy". His work was done in the early 1500s
-James D. Dana published published his first System of Mineralogy in 1838.

You mentioned rose quartz. The color is caused by microscopic inclusions of aligned silicate mineral fibers. Advanced testing has shown that they’re generally similar—but not identical—to the mineral dumortierite. George Rossman, the leader in research of the causation of color in gemstones calls this specific variety of dumortierite "didumortienite".

Similar, thorough and accurate research on causation of color has been done on all known gemstones and their varieties. Here is an excellent series of articles:

An Update on Color in Gems. Part 1: Introduction and Colors Caused by Dispersed Metal Ions

An Update on Color in Gems. Part 2; Colors Involving Multiple Atoms and Color Centers

An Update on Color in Gems. Part 3: Colors Caused by Band Gaps and Physical Phenomena


I'm sorry, I don't remember a discussion on UV light sources and fluorescent minerals. If we had one I missed, no, YOU could not end the discussion. Most gemologists use LWUV (365nm) not SWUV 254nm). UV reactions simply provide another clue when identifying an unknown, their results are not, on their own, conclusive.

With all due respect, you are approaching gem identification half ass backwards.
As with mineralogical chemistry, proven methods for identification have already been fine tuned.

May I suggest you start reading
Introduction to Gemology by Barbra Smigel, Phd, GG


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 4:45 am 
Offline
Established Member

Joined: Wed Jan 18, 2017 1:08 pm
Posts: 41
Location: Bergisches Land
Hello,
Since you said :
I am 100% certain this is either a feldspar OR a feldsparthoid. Reason #2, visually it cannot be quartz.
I don't see a way anyone ,or any wavelength of UV , could provide an end to this quest.


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 5:10 pm 
Offline
Gold Member

Joined: Thu May 12, 2016 2:18 am
Posts: 1542
I am very confident that I, and any competent Gemologist, can identify and separate Quartz from Feldspar using only standard gemological equipment.

The rest of this conversation is just inane babbling from an uneducated member. It is akin to an uneducated patient trying to instruct Doctors on the way to test for a particular medical condition because he/she has made a different diagnosis by reading things on the internet. In this case the diagnosis was made by the foremost lab on this subject in the World.


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 5:52 pm 
Offline
Established Member

Joined: Thu Mar 23, 2023 5:46 am
Posts: 19
1bwana1 wrote:
I am very confident that I, and any competent Gemologist, can identify and separate Quartz from Feldspar using only standard gemological equipment.

The rest of this conversation is just inane babbling from an uneducated member. It is akin to an uneducated patient trying to instruct Doctors on the way to test for a particular medical condition because he/she has made a different diagnosis by reading things on the internet. In this case the diagnosis was made by the foremost lab on this subject in the World.



Huh funny . . . my mom died because her "educated" doctor kept insisting she had a urinary tract infection and chose to listen to him instead of me telling her she should get a second or third opinion . . . turned out it was a rare form of bladder cancer, and all the meds they kept giving her for MONTHS to treat what they assumed was a normal infection ended up delaying surgery and killed her.

But I'm sure his education assured him he was correct, and the cancer was secretly a urinary tract infection . . .

Come to think of it . . . I haven't had ONE doctor in the last 20 years diagnose anything correctly . . . but my online research proved to be correct and I was able to correctly diagnose issues AND treat them. And no, I don't do doctors anymore . . . total waste of time.

So pardon my questioning of an educated facility . . . there are few "educated" people I have found to actually be educated. Education is an ever evolving process, not something achieved. It's always questioning the status quo, current ideas and current solutions. It's pushing for progress and better answers.

I'm sure you are aware of the "recent" discovery of dark matter (1970's). It was discovered by a woman who studied the stars, and was convinced the GREAT Galileo and his laws concerning outer space and light and matter were WRONG. Watching how the planets in another galaxy interacted with their star, she realized that by definition, our current ideas about gravity were incorrect. Gravity is the push/pull relationship between one or more objects based on size and density, and under Galileo's version, our universe would have scattered itself across the cosmos . . . there wasn't enough gravity able to be generated by the currently understood masses of planets and stars. By questioning old ideas, and those certainly more knowledgeable than herself, she introduced to us "dark matter" and was able to show that only 10% of everything is made of atoms . . . the remaining 90% still UNKNOWN.

Of course, many like you questioned her ideas (she was a woman after all), and it was years before they were accepted as fact and generated new quests for NASA to explore beyond our currently known planets.

The quest for progress IS questioning currently held ideas and "laws".

Also funny enough, some of the smartest people in the world current questioning everything AND inventing everything do NOT have college degrees, lol. Probably for the best.

You can be upset that I am challenging the ideas and seeking the "how" and the "why", but I like progress and I like learning :)


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 7:44 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
Please. This is a gemology forum.

Have you read my posts, followed any of the links I offered? Doesn't appear so. Why are you here?

I may be totally wasting time and effort with you but I feel other people will ultimately benefit from the posts which is why I am not deleting this thread.


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 8:08 pm 
Offline
Moderator
User avatar

Joined: Mon Apr 02, 2012 9:31 pm
Posts: 4015
Location: North Carolina
The story you were told about dark matter is not so. There are details here that are easy to spot with a basic grounding to put things in their appropriate context--I am not super into astronomy but I do know who Galileo was for instance. It doesn't take much further reading to confirm that dark matter was not first proposed by a woman nor in the 1970s.

I'm not trying to dunk on you with this--the point I'm making is that you need at least some basic context to meaningfully discuss a topic, much less make new discoveries.

I have a feeling that your approach here is going to be antithetical to making much progress. If you're going to assume from the start that you know more than experts in the field by default you're going to have a tough time of it.

_________________
Rough and cut classic and exotic synthetic gems:https://store.turtleshoard.com


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 8:35 pm 
Offline
Site Admin
User avatar

Joined: Sun Oct 16, 2005 12:22 pm
Posts: 21602
Location: San Francisco
Quote:
You can be upset that I am challenging the ideas and seeking the "how" and the "why", but I like progress and I like learning :)

No, you like spreading nonsense you find while trolling nutters on the the internet. Why aren't you challenging the rubbish?


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Mon Apr 17, 2023 8:43 pm 
Offline
Gold Member
User avatar

Joined: Tue Apr 05, 2016 7:58 pm
Posts: 1424
Location: San Marcos, CA
Ok I am out! Sorry to hear about your Mom. By the way I haven't really felt anyone's upset until now. We just a bunch of dumb rocks in the garden I guess. Earth is flat and all that. Sorry guys I guess we didn't need educated geologists based on the latest.

_________________
The Gem Garden
San Marcos, CA


Top
 Profile  
Reply with quote  
 Post subject: Re: Feldspar Moonstone or Milky Quartz, or . . . .?
PostPosted: Sat Apr 22, 2023 4:10 am 
Offline
Established Member

Joined: Tue Dec 22, 2020 4:13 pm
Posts: 17
Location: The Netherlands
This topic was fun while it lasted. It reminds you what happens when you are overly polite to the internet know it all's.

That being said, GIA did a huge disservice by declaring the shape as oval. The single most identifying property that can be verified by any person was wrong. In that way "mommy" did a service to the industry to point this out.

So what would you expect what happens next in the mind of the house variety conspiracy theorist?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 44 posts ]  Go to page Previous  1, 2, 3

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 7 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