-George R. Rossman

This article is included in the Spring G&G 2011 available as an online or print subscription from GIA. I have just finished reading the 15 page pdf. This is copyrighted material available by subscription only, so I am unable to reprint or post a link.

The article is what the title states; the details of the results and testing performed by Dr. Rossman, with reference to a few others, up to 2009. He includes many images and charts outlining his observations and test results.

Rossman states the following in a box titled, "Need To Know":

A bar graph included in the article measuring the weight percentage of K2O (Potassium oxide) shows Tibet, Congo and China having uniformly high levels(almost identical), Mexico in the mid range and Oregon being lowest.

In an SEM graph with a high magnification image of the surface of one of the treated stones tested, Rossman shows the highly elevated levels of Copper and Potassium contained the the glassy flux residue on the stone and compares those levels to the much lower levels of both in the stone.

In closing his report, Rossman makes the following statements and observations:
Regarding Congo

Summary through mid-2009


Although the 2010 samples and testing were discussed during the GILC conference, I am unable to publish that information without breaking the confidentiality agreement I signed. As Rossman has stated in his article, further research was being conducted on these samples by a group of scientists present during the conference and their report should be forthcoming.

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In reading through Rossman's detailed report, I am still left with a question that has been unanswered for me.
As this issue has been a passion (or obsession) of mine since 2006, I have searched for and read every document published pertaining to Andesine. I have asked many questions of many people in my search for the truth, and none have been able to answer my remaining question.

How can we be so sure that none of the Mexican Feldspar was treated and sold as Andesine? Forget that we know Andegem was the supplier of Andesine for both DSN and JTV. Forget that we know Andegem purchased, by their own admission, large quantities of Mexican Yellow Feldspar.

In every report I have read, including the above report by Rossman, none has ever tested a known treated stone that began life as an authentic Mexican Feldspar. The reports all state that the difference can be detected, but I am not seeing the testing of a red mexican yellow feldspar anywhere. Does this mean none was treated? We can't know for sure.

So my question speaks to the science included in Rossman's most recent report of testing. How do we know none of the treated samples are Mexican? In his report Rossman states that he can separate the Chinese yellow from the Mexican Yellow material using a variety of tests. Yet two of the tests he presents only raise more questions for me. This may have been answered somewhere, or the answer may live in the report I just read, but I don't see it. At the risk of asking a stupid question.....


The separation between the mexican and Chinese/Tibet/Congo material is noted in Rossmans graph regarding the wt. % of K2O (Potassium). He shows clearly that the three treated stones have equally elevated levels of K2O, Mexican is a little lower, and Oregon is the lowest. I understand that. What I don't understand is the comparison of apples to oranges. The Mexican stone is yellow and untreated, yet the Chinese/Tibet/Congo are treated.

Then in his SEM graph, he shows clearly that the "glassy flux" stuck to the treated stone is very high in Potassium and Copper, higher than the body of the treated stone. Makes sense to me.

He also states that the treated material has a much higher copper content than any of the natural material. Also makes sense.

Here is where I get lost: If the copper diffuses freely into the yellow material, elevating the copper levels to above the content of natural, then why would the potassium not do the same, thereby elevating the potassium content also? Remember the Mexican K2O content falls in between Oregon and everything else based on Rossman's graph.

Summary of my question:
1. Has a known Mexican yellow feldspar been treated with this process? If so, how does the Mexican treated stone compare to the other treated stones said to be from China/Tibet/Congo?
2. If the copper diffuses into the yellow raising the copper level, wouldn't the same be true for Potassium thereby raising the Potassium level also?

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All good questions which I've also asked. Treatment itself alters things, as we've seen in turning labradorite into "andesine" or "labrasine" or whatever you want to call the frankenstone.

In addition, and although I appreciate the report and work done, one still has to wonder about sampling. Years ago, there were pictures of a supposed yellow "sunstone" operation supposedly in Inner Mongolia, but it turned out that the Chinese government hadn't heard of it (which speaks volumes). Has this "mine" yet been properly examined and documented? I think not, and it is hardly impossible that this mine was fabricated simply by trucking a backhoe and a load of material mined elsewhere out to the desert and salting.

Does all Mexican labradorite–bytownite have an identical potassium content range? Given the huge size of the Mexican deposit, I think that variations are not only possible, but probable. Once material is carted off, it cannot be treated as if we are dealing with samples properly collected from virgin soil/rock within a deposit.

I have huge reservations with the current situation in which miners, dealers and others who may have conflicts of interest are being relied upon to provide samples. It is reasonable to go out into the market to sample what is being sold to the public, but it is a fundamental error to make suppositions as to source without carefully ensuring that reference stones attributed to a certain location were properly collected and documented by independent geologists (not restricted tours, not materials provided by third parties, etc.).

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rocks2dust
My rocks on Search4Gems

It will be interesting to see what comes in the next report. There should be additional information coming that will involve other scientists as well. I anticipate seeing that sometime in August.

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What is most interesting to me is the reasoning behind Dr. Rossman's choice to limit his summary to work done prior to 2010.

This effectively excludes the most damning evidence.

Personally speaking, I am hoping that this will be wrapped up within the next couple of months. While there are still conflicting viewpoints over the matter, there is information (and in some instances the lack thereof) which should lead to consensus. I also believe that with time, the full story shall emerge regarding source materials. As mister Shakespeare wrote, "the truth will out".

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I can't speak for his reasoning behind the date limit. I can tell you a "task force" was established at the GILC Conference in Tucson, and they asked for 6 months to study together. It is my understanding that we should be hearing something by August. Fingers crossed. Hopefully it will all become clear.

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