Thursday, May 20, 2010

Oregon sunstone and treated feldspar from Mexico are easily identified by Raman photoluminescence: Rossman and McClure's findings in error

ISG: The story of the ISG Raman Microscope scans of andesine.
Numerous errors in claims and reports abound throughout the industry!
At the recent Sinkankas Symposium on Gem Feldspar, Dr. George Rossman posted up a slide (you see at left) of one of our composite Raman scan images and declared our findings to be incorrect.....based on a quote he attributed to us that we never made. Indeed, Dr. Rossman has never seen any of our study specimen group (in spite of our offering same) and has not actually tested any of our specimens. And yet, he incorrectly made the declaration that we were wrong in our findings.
The problem: what he claimed we said wrong, we did not say at all. What we did say...he totally ignored.
Confused? So are we! This brings to light the problem with this entire andesine fiasco, certain members of the industry have continually tried to protect the alleged perpetrators of the andesine problem at the expense of truth.
Since Dr. Rossman chose the Symposium at the GIA to present his case without our having the opportunity for rebuttal of his statements, we feel it only fair that we have the opportunity to do so here
We will first share with everyone what our andesine study group actually looks like...or at least part of it. Rather than allowing the alleged perpetrators of the andesine fiasco to supply our specimens, the ISG has purchased hundreds of specimens on the open world markets. We have sought out mine owners from the various mines to obtain proper specimens from as many locations as possible, received specimen submissions from consumers for testing, and we have paid for virtually all of our other specimens so that our research will remain independent and without encumberance to outside influence. Pictures of just a few are below including the inbound shipping envelopes we maintain for records.

With the help of many consumers who wanted answers, the ISG obtained an Enwave Raman Microscope that we had custom built with a Meiji Techno MX microscope. We proceeded to do over 1000 Raman scans of the specimens including specimens from all origins and all colors. The image you see at the top of this page is only a single composite of two scans. We thought you would be interested to see the whole ISG Raman Story.
We wish to acknowledge and thank Marty Haske of Adamas Gemological Laboratory for his research and website covering the topic of Raman Photoluminescence. Mr. Haske's work proved pivotal in our research to identify the diffusion treatment of andesine. Here is how it worked......
In the image at left you see a composite of many scans done on Oregon Sunstone from as many mines as we could gather. We have literally thousands of specimens of Oregon Sunstone in our office, and the Raman Photoluminescence scan you see at left is classic for all.
Then, we tested a number of the Chinese and Mexican feldspar specimens.
At left is a composite image of the scans from the Mexican yellow feldspar and Chinese red andesine. The Chinese andesine includes stones claimed to be from Tibet, Mongolia, and the Congo.
As you can see, we did not rely on the peaks as claimed at the Sinkankas Symposium, but rather the whole of the Raman Photoluminescence reaction.
With over 4 kilos of Casa Grande/Chihuahua Mexican material, and several hundred Chinese andesine, the results we got were repeatable, and verifiable in stone, after stone, after stone, after stone....you get the idea.
Once we compared the three groups, we found that indeed the Oregon Sunstone had a unique, predictable and repeatable Raman Photoluminescense result, and that it was significantly different than either the Mexican or Chinese andesine.
In all cases, the Mexican and Chinese material all tested out the same.
Which....was our first report: That the Chinese andesine tested the same as the Mexican andesine with the Raman.
But we did not stop there.
We obtained transparent plagioclase feldspar specimens from as many sources as we could find and verify. These included: Madagascar, Oregon, Mexico, Tibet, Mongolia, Congo, India, and Tanzania.
As you can see at left, each source had a unique Raman Photoluminescent reaction with the exception of the Mexican and Chinese. These were identical.
This was the crux of our Raman reports, and our findings that the Chinese andesine tested the same as the Mexican feldspar. Did it actually originate from Mexico? Who really cares? We don't. But apparently someone at Caltech and DSN cares. However, as the California Appeals Court ruled in the past few days, the origin of the material is not as important as the selling of the diffusion treated andesine without disclosure. The origin is of little or no importance based on the findings of the court in deciding against Direct Shopping Network in their lawsuit.
But there is one step further we need to go in this ISG Raman Story....
"The GIA is currently unable to separate diffusion treated red Tibetan andesine from natural red Oregon Sunstone," GIA Executive at the Sinkankas Symposium
Also at the Sinkankas Symposium a high ranking GIA executive made a presentation statement that you read above. The GIA cannot separate the natural red Oregon Sunstone from the diffusion treated Chinese material. Regardless of the refractive index differences that we have already demonstrated, the Raman Photoluminescense can.....well, I will let you see for yourself.
At left is a Raman Photoluminesence composite of a Plush Oregon Sunstone and a Tibet red diffused sunstone.
Can you separate these two?
Just for arguments sake, we performed a set of scans on Plush Oregon sunstone and a tray of Mexican yellow feldspar and Chinese red diffused andesine.
Again, the image speaks for itself.
At the risk of appearing flippant and/or a bit sarcastic, I will tell the following true story......
I gave my 8 year old son 2 red stones and had him perform scans with our Raman Microscope. He was able to separate the Oregon Sunstone and the Chinese diffusion treated andesine by Raman Photoluminescense. He has no idea how it works technically, but the Enwave Raman and support software has advanced to the point that even an 8 year old can separate natural Oregon Sunstone and diffusion treated Chinese andesine. Seriously!
With the ruling of the California Appeals Court that says Direct Shopping Network failed to prove a prima facie case on any of their accusations against myself and Interweave this is only the end of one chapter in this never ending story.
The next part goes to Andegem and the AGTA who DSN blames for all of this. Andegem for supplying it, and AGTA for certifying it as all natural and untreated. We have implored both of these organizations to step up and do the right thing before lawsuits and court rulings began. They failed to do so.
Perhaps they will now since DSN seems to be willing to throw both of them under the bus.
But that.....is another story.
Robert James
President, International School of Gemology

2 comments:

  1. Very interesting statistics. I think oregon sunstone and fire opal are gorgeous rocks. I'd love to purchase some one day.

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  2. Thanks for sharing it........
    Meiji Techno is a modular tool equipped with a custom made system, which is used for research application.
    Meiji Techno

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