Final Edition of the Feldspar Testing

[YourGemologist]

Here is the last installment on the feldspar issue. Some thoughts are below.
================================================== ====

More facts on our feldspar testing report!

Based on requests for more of our results!

As a licensed Property and Casualty Insurance Adjuster I deal in facts, not truths. Because one man’s truth is another man’s untruth. But facts are verifiable and stand up in court. Truths are often not verifiable and rarely stand up in court.

We have already established the facts that the JTV feldspar is not equal to the Oregon Sunstone Labradorite in gemological properties or quality. And we have established the fact that it is possible to separate the Oregon labradorite from the JTV feldspar with a refractometer and a trained gemologist who knows how to get an optic character and sign as well as an RI.

But I have been challenged to present other facts of our test results regarding consumer questions on the color. Because there are a few who are picking and choosing which of our facts they want to deal with, and which they do not wish to deal with. Rather than armchair quarterbacks, I like to call them armchair gemologists.

So here are more, but not all, of the facts on our investigation of this topic. And we turn to Dr. Rossman of the CalTech Internet Site that provides the absorption spectrum for red and green Plagioclase Feldspar, Ponderosa Mine , Oregon Reference: Hofmeister and Rossman, Exsolution of metallic copper from Lake County labradorite. Geology 13, 644-647 (1985).

Below is that spectrum graph.

You can see an absorption spike at around 580nm. Next, I want to take a look at the actual absorption spectrum in visible light from the red (below left) and green (below right) labradorite from Oregon . Notice below that the strong absorption band in the 580nm area is in complete factual agreement with the absorption graph provided by Dr. Rossman. I have reversed the red/blue sides to accommodate the US readers.

Next, we want to look at the absorption spectrum of the JTV red and green feldspar. Note that the red feldspar (below left) is identical to the Oregon red labradorite, but the green feldspar (below right) shows no visible spectrum.

Based on these facts, a reasonable person might expect that the JTV green feldspar is of a different coloring element than the red. But that the red JTV feldspar could indeed be colored by the same element that is coloring the Oregon material. Namely: native copper.

But here is where another fact comes to play. Copper in the Oregon Sunstone Labradorite leaves very unique inclusions. Namely copper granules inclusions as we see below on the lower left and center of both of the images.

And in virtually all of the Oregon rough material that we inspected (we have several bags that were sent to us) all of the material exhibited some type of native copper inclusion.

The problem is that this fact does not hold for the JTV red feldspar. In fact, the JTV feldspar shows virtually text book inclusions for the oligoclase sunstone feldspar found in India . Below you can see some photographic examples taken in our lab.

First, as outlined in the PHOTOATLAS of Inclusions in Gemstones, E Gubelin and J Koivula, 1997 edition, the Indian oligoclase feldspar is known for the platelet inclusions of hematite. In fact, the image below left could be right out of the book had it not been taken in the ISG office a few hours ago. But below right is the same shaped platelet inclusion, including the same rhomb shape and termination cut, that was photographed in a JTV red feldspar. Compare them. No gemological textbook lists any other feldspar as having this type of inclusion but oligoclase sunstone from India.

And below left again is a ribbon inclusion from an oligoclase Indian sunstone. And at right are ribbon inclusions that we have only found in a JTV red feldspar. We find no reference to any other feldspar having this kind of ribbon inclusions except oligoclase sunstone from India .



Now, we have a few facts to line up:

Fact: The JTV red feldspar and the Oregon Sunstone Labradorite have the same absorption spectrum.

Fact: The Oregon Sunstone Labradorite shows textbook inclusions for a labradorite feldspar colored by native copper with verifiable copper inclusions.

Fact: The JTV feldspar shows textbook inclusions for oligoclase sunstone from India .

Based on these facts we can draw one of two possible conclusions:

Conclusion #1: That the JTV red feldspar has textbook inclusions for oligoclase, an exact match for the Oregon Sunstone Labradorite spectrum, which by a remarkable quirk of nature gives it the color of a very rare type of labradorite feldspar while all of the inclusions of a common type of oligoclase feldspar. Or

Conclusion #2: That someone has taken some cheaper and more plentiful Indian oligoclase feldspar and diffusion treated it with enough copper to impart the Oregon labradorite color, and spectrum.

And we know after the beryllium sapphire treatment fiasco that many labs can be fooled by a new diffusion treatment. And that some diffusion treatments can be very difficult to identify until the method is known.

But occasionally an anomaly will happen that allows the diffusion treatment to be easily identified. Such as the blue halos in the Be treated sapphires. But one of the industry’s accepted first tests to identify diffusion treatment is to use an immersion cell to inspect the facet junctions. Because diffusion is sometimes known to cause color concentrations along facet junctions. Not always, but it is a strong indicator when you do find it, and it is an industry standard test.

So we simply started looking through all of our known JTV red feldspars and one indeed presented itself that showed red color concentrations along the facet junctions.

Now, if we take all of our facts together. We have (a) a red feldspar with properties below labradorite, (b) a red feldspar showing textbook inclusions of plentiful oligoclase feldspar, (c) a red feldspar showing a classic color of a rare red labradorite, (d) a red feldspar showing a spectrum of a rare red labradorite, and (e) a red feldspar that demonstrates clearly defined color concentrations that indicate diffusion treatment.

Based on these facts, and until more facts are attained, it is our position that the most reasonable and justified conclusion is that the red feldspar that has been sold to us and that we have in our office, is most likely a form of oligoclase feldspar that has been diffusion treated. By what method or with what element, we do not know. But the facts leave us with no alternative that could explain what we have.

If anyone has more facts on this issue, such as Dr. Rossman and his upcoming report, we welcome them. And as new facts are received we are certainly ready to adjust our position based on the new facts.

We welcome any professional responses, additional facts, and evidence regarding this matter. Otherwise, we will wait until more facts are available. At which time we will review our position.

And this is, once again, for all of the consumers out there who have been essentially patted on the head, slapped on the butt, and told to go sit down when they asked for answers on this issue from the gemstone industry.

We have not provided you with the final answer, but we have provided you with facts. And beyond that perhaps our facts and questions will motivate the industry to get some answers for you. And whatever action may or may not be required.

At this point we have given you all we have to give you, other than a few more facts that we just don’t have time for here. In the future we will have our own RAMAN and other technology to provide you with more assistance. Until then, we will have to wait along with you.


Robert James FGA, GG
Fellow, Gemmological Association of Great Britain
Graduate Gemologist, Gemological Institute of America
Property and Casualty Adjuster, Texas Department of Insurance #1300433
Certified Continuing Education Provider, Texas Department of Insurance #3391 (and others)

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About Us: JewelryAdjuster.com is part of the family of gemological reference and study sites established by Robert James FGA, GG. These educational websites are operated under the registered name of the International School of Gemology located in San Antonio, Texas. The ISG provides educational services to the jewelry and insurance industry through our ISG Registered Gemologist and ISG Registered Gemologist Appraiser titles, and to the insurance industry through our certified CE courses relating to jewelry and gemstones. For 5 years Robert was Senior Gemologist / Buyer in the Claims Replacement Service and Gemological Laboratory of USAA Insurance in San Antonio, Texas. During these 5 years, Robert worked to establish new procedures that were adopted in the operations procedures for USAA, and taught classes for underwriters, policy service staff, adjusters, and Special Investigations Units throughout USAA. Robert was also active in the SIU division and assisted in the Major Claims division for USAA Special Investigations Unit.





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[YourGemologist]

Everyone, one note on something I am seeing posted at various places. And this is not for anyone in specific, just an FYI for everyone.


Getting a cup, putting some baby oil in, and dropping a stone in...is not an immersion cell.

You have to have a proper light source, and most important you have to know what you are doing.

I am seeing some people just pour out some baby oil and drop a stone in. First time to try to make an immersion cell and already they are experts.

This is not the way to do it. Unless you are trained on what you are seeing, have the proper light capabilities, and have some experience using an immersion cell with known stones to know the reactions, you are not going to know what you are seeing......and not seeing.

I am reading about people just dropping the stone in the baby oil, no light, no training, and no experience. And thinking they can make a proper gemological evaluation.

This is just not possible.

Just a note. If it was that easy everyone could do it. But it takes proper conditions, proper training, and proper experience on this level we are talking about here.

Just an FYI. I appreciate the efforts but this stuff on the JTV issue is not school and classroom, this is for some high stakes. Please understand the level of standards that are required on this.

Robert

[Smith]

Originally Posted by YourGemologist

Here is the last installment on the feldspar issue. Some thoughts are below.
================================================== ====

More facts on our feldspar testing report!

Based on requests for more of our results!

As a licensed Property and Casualty Insurance Adjuster I deal in facts, not truths. Because one man’s truth is another man’s untruth. But facts are verifiable and stand up in court. Truths are often not verifiable and rarely stand up in court.

We have already established the facts that the JTV feldspar is not equal to the Oregon Sunstone Labradorite in gemological properties or quality. And we have established the fact that it is possible to separate the Oregon labradorite from the JTV feldspar with a refractometer and a trained gemologist who knows how to get an optic character and sign as well as an RI.

But I have been challenged to present other facts of our test results regarding consumer questions on the color. Because there are a few who are picking and choosing which of our facts they want to deal with, and which they do not wish to deal with. Rather than armchair quarterbacks, I like to call them armchair gemologists.

So here are more, but not all, of the facts on our investigation of this topic. And we turn to Dr. Rossman of the CalTech Internet Site that provides the absorption spectrum for red and green Plagioclase Feldspar, Ponderosa Mine , Oregon Reference: Hofmeister and Rossman, Exsolution of metallic copper from Lake County labradorite. Geology 13, 644-647 (1985).

[FONT=Arial][SIZE=2][COLOR=#333333]Below is that spectrum graph. [COLOR=#000000][COLOR=black]
[COLOR=#000000]
[SIZE=3]You can see an absorption spike at around 580nm. Next, I want to take a look at the actual absorption spectrum in visible light from the red (below left) and green (below right) labradorite from Oregon . Notice below that the strong absorption band in the 580nm area is in complete factual agreement with the absorption graph provided by Dr. Rossman. I have reversed the red/blue sides to accommodate the US readers.

Next, we want to look at the absorption spectrum of the JTV red and green feldspar. Note that the red feldspar (below right) is identical to the Oregon red labradorite, but the green feldspar (below left) shows no visible spectrum.

Based on these facts, a reasonable person might expect that the JTV green feldspar is of a different coloring element than the red. But that the red JTV feldspar could indeed be colored by the same element that is coloring the Oregon material. Namely: native copper.

I think you may have the spectrums crossed on the JTV green and red feldspar as the green shows a readable pattern identical to the natural in your images.

[YourGemologist]

Yep, no doubt I will get flamed for that. I will send out a correction.

Robert

[Bouvet]

Originally Posted by YourGemologist

Everyone, one note on something I am seeing posted at various places. And this is not for anyone in specific, just an FYI for everyone.


Getting a cup, putting some baby oil in, and dropping a stone in...is not an immersion cell.

You have to have a proper light source, and most important you have to know what you are doing.

I am seeing some people just pour out some baby oil and drop a stone in. First time to try to make an immersion cell and already they are experts.

This is not the way to do it. Unless you are trained on what you are seeing, have the proper light capabilities, and have some experience using an immersion cell with known stones to know the reactions, you are not going to know what you are seeing......and not seeing.

I am reading about people just dropping the stone in the baby oil, no light, no training, and no experience. And thinking they can make a proper gemological evaluation.

This is just not possible.

Just a note. If it was that easy everyone could do it. But it takes proper conditions, proper training, and proper experience on this level we are talking about here.

Just an FYI. I appreciate the efforts but this stuff on the JTV issue is not school and classroom, this is for some high stakes. Please understand the level of standards that are required on this.

Robert

From what I've seen and read whenever I get the occasional google link to that forum, is that there are a lot of misinformation that get posted, without anyone bothering to check it's accuracy, or even to correct it.

The level of incorrect and unuseful advise is enough to keep me away, sure there are some info that are good, but like lisa said the other day, I also don't have the time to filter the bad from the good.

I sometimes wonder though as to the real reason of having such a gemology forum, and why so much unreliable information?
Are there any real gemologists that actually moderate the site? and why aren't they doing it?

I feel really sorry for all those folks that go there seeking answers, you can sometimes find better info on google.

[ravirus]

Originally Posted by Bouvet

I sometimes wonder though as to the real reason of having such a gemology forum, and why so much unreliable information?
Are there any real gemologists that actually moderate the site? and why aren't they doing it?

Hi
i think it's quite easy to check for admin/mod/forum member credentials
alberto

[Willy]

It is real easy to look at what a person posts and wants you to see in the way of credentials, education, etc., but it is not always that easy to verify it, especially in this age of deception.

[YourGemologist]

That is a good point, Willy. Indeed, it is very easy for someone with no knowledge to post up credentials and act as if they are well trained. And with the anonymity of the internet, they can get away with it until their lack of knowledge catches up with them.

Or someone like a Senior Buyer from Jewelry Television can act like some industry expert from somewhere else, its no problem. Just go by a couple of initials, for instance, rather than a name. We have had it happen here, it can happen anywhere.

On the internet anyone can be anything, until their lack of knowledge or hidden agenda is exposed. Very difficult to find out who people really are if they want to be sneaky.

On a side note: I am getting a lot of information on the QT regarding our report. Particularly from some dealers in the Far East.

Based on the reports, our evaluation of this material is right on the money. The exact how and who is still unknown. But the what seems to be right on.

I have not had a single person write to me to say they have seen the rough of this andesine material.

Not on person from that region has written to say anything other than ALL of the material (even the Congo material) is all coming out of China, and its all cooked.

Also, one more issue:

We did not include anything further about the green JTV material in the final newsletter on the topic. I felt we had covered that pretty well, and it is pretty much a slam dunk as far as I am concerned. So it was the red material that needed the additional info, which is what we did.

Time will tell.

Robert

[bob]

you might look toward radiation it can cause defects in plagioclase to expand into nanometer sized tubes that could provide a diffusion pathway

[YourGemologist]

Bob,

That is a very good point. We are hearing that one possible scenario is that the material is being radiated, then tumbled in a high copper/iron environment for months.

Which would account for the immersion cell reaction to the greens.

Excellent point.

Robert