Category Archives: grain boundary diffusion

Grain Boundary Diffusion in Tourmaline; The Epochal Crisis, Part II; A Tempest in a Tabloid:

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An Open Letter to David Federman, Editor-in-chief, Colored Stone.

by Richard W. Wise, G.G.

David Federman, I just finished reading Joel Arem’s article Ending Diffusion Confusion in the current issue of Colored Stone together with your editorial titled Some Badly Needed Science. You have written so many open letters to the gemstone industry I thought I would try my hand at writing one to you. Given your reception of my January letter to the editor, I decided that the wisest course was to publish my opinion here.

First question; who is confused? For over a year you have repeatedly published your claims that tourmaline, topaz and tsavorite are being diffusion treated with little backup up of those claims other than your “long simmering suspicions” and the unsupported evidence of one man while many experts in the gemological community have been saying that the evidence presented to support those claims is just plain wrong. You state:

“Was there a better way to test James’ conjecture? I think so…It’s called experimental gemology.”

I find it ironic that you are suddenly calling for “experimental gemology.” I agree with your call, but let’s, just for a change, accurately define our terms. Continue reading →

Copper Diffusion; Is It Gemology's Worst Nightmare?

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Wednesday, September 24, 2008

Copper Diffusion; Is It Gemology’s New Worst Nightmare? Part I

By Richard W. Wise, G.G. ©2008

The Latest From Bangkok?

Rumors are reverberating through the gem trade that gem alchemists in Thailand have developed a method to diffuse copper into tourmaline. This method converts low-end pale blue tourmaline into highly saturated material similar to the high priced cuprian tourmaline currently coming out of Mozambique. The first salvo was fired by Ted Themelis a well known expert on gem treatments and repeated in an article by David Federman in Colored Stone Magazine. One of my sources, a dealer active in Bangkok, wrote me two weeks ago claiming that some of this material had actually been certified as cuprian or “Paraiba” type tourmaline by an unnamed gem laboratory. (image above left; gemologist John Koivula lectures at the World of Gems Conference, Chicago)

Adding more fuel to the fire, just as I was about to leave for the World of Gems Conference (WOG) in Chicago, Robert James, FGA, President of The International School of Gemology (ISG) released a study that suggests that tourmaline, even some of the pricey Mozambique cuprian tourmaline is deep-diffused with copper to improve its color. The conference was abuzz with Mr. James’ contentions. Though deep diffusion was not on the agenda, everyone seemed aware of the article and James conclusions were much discussed. Unfortunately, James, who had planned to attend, was unable to due to Hurricane Ike.

This is James’ second broadside in a series. In the first installment he published a study that he says proves that Andesine is being bulk diffused with copper. Many of the gemologists I spoke to in Chicago expressed admiration for the James chutzpah while at the same time questioning both his methodology and conclusions. Stuart Robertson, Research Director of Gemworld International summed up the views of many of the gemologists attending the WOG Conference: “his conclusions on andesine may be right, but his science is flawed. He is way off base on tourmaline.”

Andesine Diffusion Has Arrived:
“Ive been able to turn it red in the lab.”
Dr. John L. Emmett

“I’ve done it” said Dr. John Emmett said in an interview just yesterday when I asked about copper diffusion in andesine. “I’ve been able to turn it red in the lab and made some that look like a good ruby.” The real issue says the former associate director of the Lawrence Livermore Laboratory is differentiation. Emmett, whose firm, Crystal Research, specialized in heat treating Montana sapphire, has tested labradorite from all the major sources, including Oregon sunstone and Mexican material from the Casa Grande mine. “There is natural labradorite, heated labradorite and copper diffused labradorite.” The question now is how do you tell the difference? Emmett prefers the term labradorite to andesine because, he says, the demarcation between the two is completely arbitrary.

Studies of this kind are normally done in well equipped gemological laboratories and subjected to a long process of peer review. Preliminary findings are submitted to colleagues, methods and are minutely scrutinized and conclusions challenged. This time consuming process works to the benefit of the scam artists. Gemologists are put in the position of always playing catch up. Why is this the case?

“Gem labs are sitting there fat, dumb and happy.”
Dr. John L. Emmett

“The problem is, gemology is an observational science not an experimental science”, Dr. Emmett stated. “Gem labs are sitting there fat, dumb and happy.” No one is doing the research. If GIA had put together a small research team in the 80s when surface diffusion first became an issue they would have discovered all the possibilities and would have been able to identify the possible diffusion treatments before the Japanese bought 100 million dollars worth of Beryllium diffused padparadascha sapphire.

Peer Review Goes Public:

James decided to shortcut the review process and has courageously or foolishly, depending upon your point of view, chosen to go public before completing his research, opening himself to a potentially painful process of public review. As luck would have it, several of the world’s leading gemologists; John I. Koivula, Chief Gemologist at The Gemological Institute of America (GIA), Dr. Lore Kiefert, head of the AGTA lab were in attendance and I took the opportunity to raise the issue of tourmaline diffusion with them and a few others. Stay tuned!