Showing posts with label cuprian mozambique. Show all posts
Showing posts with label cuprian mozambique. Show all posts

Wednesday, February 11, 2009

Drama In The Desert: ISG Seminar---A Dry Hole!



Drama In The Desert: ISG Seminar--A Dry Hole:

by Richard W. Wise, G.G.


The much ballyhooed "Epochal Crisis" never quite materialized at the International School of Gemology's "Let the Science Speak" seminar held February 6th at the Arizona Hotel. In a rambling presentation, ISG President Robert James
back-pedaled on some of his previous statements and presented the results of advanced tests that contradicted his own theories.

The silence was eerie. It was painful to watch. Thanks to Colored Stone Magazine's drum beating, the talk was attended by a who's who of gem scientists. James' attempts at folksy humor fell flat. The scientists sat quietly and listened to the presentation of evidence. After the presentation, they politely applauded, asked few questions and filed out, leaving Robert James' reputation as a gemologist in a heap of smoldering ruins.

In a series of internet broadsides last September, James made sweeping claims that large amounts of Mozambique cuprian, as well as other tourmaline, were being subjected to copper diffusion treatment. Recently he c
ast his net wider, suggesting that what he now calls Grain Boundary Diffusion, is being used to improve the color of not only tourmaline, but garnet and topaz as well.

Goop In The Tubes:

The presentation centered on what James called "goop in the tubes." Hollow growth tubes are a characteristic tourmaline inclusion. What James finds telling is the fact that in some Mozambique tourmaline, these tubes are filled with a yellow-red substance that James cannot identify. In a previous GemWise blog, serious questions concerning these claims were raised by John Koivula and Christopher Smith, questions that James failed to address. In a significant variation on last September's theme, James has now backed away from his claim that the filling material is copper. In fact, he carefully avoided using the term copper diffusion throughout the lengthy talk.

James showed slides showing what he calls diagnostic "footprints" which prove treatment. However the footprints he finds in topaz do not in the least resemble the "footprints" he finds in tourmaline. His tourmaline slides showed straight growth tubes; his topaz slides showed a spider web of tiny lines. He presented absolutely no proof of diffusion in tsavorite garnet; he simply suggested that the appearance, in the past decade, of tsavorite over two carats is ominous. He never explains how that relates to his diffusion theory. Last September, he claimed he discovered that undisclosed amounts of synthetic tourmaline were being sold, but now admits that he was wrong. (image right: large chunks of tsavorite rough from a 2007 strike at the Scorpion Mine, Voi, Kenya, that yielded several stones above 10 carats. Courtesy: Tsavorite USA)

The conclusions drawn from the advanced testing promised last September conclusively demonstrated that James understands neither the characteristics of his test material, nor the diffusion process itself. According to James, LA-ICP-MS testing (commonly called laser ablation) conducted by Evans Analytical showed differing concentrations of manganese and iron in the tourmaline samples tested, with higher concentrations toward the center of the specimens. James suggests that this is another "footprint" left b
y the treatment process, and fails to note that the characteristic color zoning in tourmaline is the result of compositional differences within the stone. For example, higher concentrations of manganese produce richer pink zones in tourmaline. In a later Q&A session, when the soft-spoken Dr. Adolf Peretti, former head of the Gueblin Lab and President of the GRS Lab in Bangkok, told him flat out that varying concentrations of elements are characteristic of natural tourmaline, James suggested that Peretti's test samples had been altered by diffusion. (photo left: Gemology 101, a natural "footprint" crystal cross-section: pink color zone caused by concentrations of Mg. in the center of the crystal. Similar images exist in the literature going back 150 years)

How Diffusion Works:

Diffusion is the word currently bandied about, but what is it, what does the term mean? Let me share with you an analogy suggested to me by one of the world's leading authorities on the use of diffusion treatment in gemstones:

Consider a dollop of blue ink dropped into a glass of water. The ink will slowly diffuse throughout the water, eventually turning the water a uniform light blue. Ion diffusion, or deep diffusion, works exactly the same way. Diffusion moves from higher to lower concentrations. Just as the ink does not remain concentrated, outside substances such as Beryllium and copper, when introduced into gem material, spread out and diffuse throughout the material. The ions do not concentrate as James suggests--concentration is the result of slow natural crystal growth and results in zones of color, a common trait in tourmaline. Thus, James' advanced testing proves, as Dr. Piretti and Dr. Kiefert have pointed out, exactly the opposite of James' contention. Concentrations of manganese and iron in tourmaline prove that the color is natural.


Industry writer and James acolyte David Federman has been warning for months that James' presentation would spark what he terms as an "epochal crisis" in the gem trade. Abandoning any pretense of objective journalism, he has written three articles praising James and ignoring prominent scientists such as John Kiovula, Richard Hughes, Christopher Smith and Ted Themelis who profoundly disagree with James' methods and conclusions. In the current Colored Stone, Federman says we are living in "gemological end-times." What did all this apocalyptic rhetoric amount to? What James actually presented was mostly old, largely discredited information that although full of sound and fury, flies in the face of science and logic and proves his own theory to be totally false.

AGTA and GJX:

There was definitely more action at the gem shows, but then gems are the major reason most people are here in Tucson during this two-week period. Most dealers I interviewed said that sales exceeded their expectations, though they didn't say what those expectations were. All signs point to a tough year ahead. As dealer Chris Johnston pointed out, its a Darwinian crisis, and as usual, the strong will survive.


Visit Burma's Valley of the Serpents and learn how sapphire is mined and graded. Follow me on gem buying adventures in Burma, Thailand and Sri lanka. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.


“Wise is a renowned author... He’s done a marvelous job of this first book
, monumental work, a tour de force...My recommendation: Buy this book”.
Charles Lewton-Brain, Orchid


whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."



Midwest Book Review
April 2006

Only $39.95 in paperback. Read a couple of chapters online an order: We recently discovered about a dozen copies of the out of print hardcover: $79.95 signed by the author www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

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!

R. W. Wise Unveils New Website:

Finally the new website is up and running. We can boast a number of updated features:

The new site is quicker loading. The homepage looks more like a newspaper front page with a changing array of new designs from our workshop and a monthly featured gemstone.

One Click Access:

The search function at the top of the page allows you to navigate to any part of the site with a single click. You can view our entire gem, contemporary or antique jewelry inventory or go right to rings.

Multiple Large Product Images:

Now you can see the jewelry top, front and back. Gemstones sport multiple image much larger than the old site. You can really get a sense of the gemstone., multiple larger images of each gem.

Prices too...

We love to talk to our gems and jewelry and I doubt that anyone is going to buy a fine piece of jewelry or a gemstone without having questions. Still no market basket and we will maintain this policy of not pricing our finer pieces, but many pieces will now be priced. We have also updated the query form and will be pleased to call you with information. Take a look: www.rwwise.com


Visit Burma's Valley of the Serpents and learn how sapphire is mined and graded.

Follow me on gem buying adventures in Burma, Thailand and Sri lanka. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.

“Wise is a renowned author... He’s done a marvelous job of this first book, monumental work, a tour de force...My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Only $35.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com


Wednesday, April 30, 2008

Paraiba Tourmaline; The Controversy Goes on and on…:



GIA Weighs In:

The Spring 2008 issue of GIA's Gems & Gemology features a full length article on Mozambique cuprian tourmaline. Under the heading “Nomenclature Issues” the authors, there are eight of them, four work for GIA, make the point that the now infamous Laboratory Manual Harmonization Committee (LMHC) has made it optional for its member to use the term Paraiba as either a variety designation or a trade name. The members of LMHC include AGTA, CISGEM, GAAJ, GIA, Gubelin and SSEF. Most members, they note, have opted to use Paraiba as a trade name. (Photo: above left: The real thing, 0.88 carat Paraiba Tourmaline from Paraiba, R. W. Wise collection)

A new wrinkle has been added. According to LMHC Information Sheet no. 6, Paraíba Tourmaline is defined as “a blue electric blue, neon blue, violet blue) or green elbaite tourmaline of medium to high saturation. That the gems have the proper chemistry, be copper and magnesium bearing is not sufficient. Violet, reddish-purple and yellowish green gems are excluded by definition and, say the authors, “The saturation necessary for blue-to-green Cu (Copper) bearing tourmaline to be considered ‘Paraiba’ does not have widespread agreement.” (Photo: above right: Exceptionally fine pair of Mozambique cuprian "Paraiba" tourmaline)

This definition offers up all sorts of interesting possibilities in the ongoing certificate game. One lab may decide that a given stone has sufficient levels of saturation and is of the proper hue to be called Paraíba while another lab might simply call it “Cu- and Mn-bearing.” This creates a situation similar to the LMHA decision regarding pinkish-orangy sapphires. Depending upon saturation, the lab may decide the stone is or is not padparadscha. For years now labs have been making a distinction between emerald and green beryl on the basis of saturation. This means that getting a Paraiba certificate on may be something of a crap shoot.

Reductio ad absurdum:

The decision to define the hue/tone of Paraiba tourmaline might have another embarrassing if unintended consequence. Gems from the original Paraíba mine, some of which, particularly the unheated material, was definitely in the violet and reddish purple hues described above, will no longer fit the definition of Paraiba tourmaline while stones of the appropriate hues from Mozambique and Nigeria will. Oh what a tangled web we weave!

Not Quite Like Padparadascha:

In a recent article The Paraiba Predicament posted on the Colored Stone website www.colored-stone.com Editor in Chief David Federman draws a comparison between the current tourmaline terminology issue and a similar debate over the use of the term Padparadscha sapphire.

In the 1980s a large strike of fancy colored sapphire was found in the gem gravels of the Umba River in Tanzania. These included a portion of reddish-orangey-pink-brownish-red stones that were marketed as African Padparadascha. (Photo: left: 3.96 carat Natural Sri Lankan padparadscha sapphire, R. W. Wise, Collection) Many in the trade found this objectionable. In the 1983 article published in Gems & Gemology, legendary gemologist Robert Crowningshield defused the controversy by defining the color of padparadascha. This is correct. However, Federman goes on to say:

“Although "padparadscha" referred to color rather than place, it was always assumed that this corundum had one origin only: Sri Lanka. So use of the term "padparadscha" implied a single source.”

Federman’s analogy breaks down on a question of fact. Crowningshield did exclude Umba River stones from the definition not because they were from Africa but because, as he states in the referenced article, these gems were a brownish orange to deep orangy-red did not, therefore, fit the definition of padparadscha. Crowningshield did not exclude stones simply because they were not of Sri Lankan origin. The term padparadscha "implied" a single source only because, at that time there was but one source.

Since that article was published a number of natural stones from Vietnam and East Africa from newer sources have entered the market. These gems fit Crowningshield’s definition and qualify for the designation padparadscha despite lacking the traditional geographic lineage. Padparadscha as defined by Crowningshield as “light to medium tones of pinkish orange to orange-pink hue.” This is the same definition that I use in my book, Secrets Of The Gem Trade, and it has become universally accepted in the trade.

In his seminal Ruby & Sapphire, Richard Hughes appears to draw the same conclusion as Federman but goes on to say that “The best ‘padparadscha’ this author has seen was unearthed in Vietnam, not Sri Lanka.” He goes on to say that the best way to resolve the controversy would be to define the color range (p.398). Ironically, he suggests that a “set of printed color references” (ibid.). Two years ago, the LMHC came up with just such a set of color references which has generated its own set of problems. (see GemWise: Boldly Going...)

Well the best padparadscha this author has seen was found near Songea, Tanzania and who knows where the next one will come from. Actually a few stones from the old Umba River source also fit Crowningshield’s definition.

Just Do The Right Thing:

The fact is that none of the issues and absurdities associated with the current nomenclature would be issues at all if CIBJO and the labs had done it right in the first place. For the past fifty years every new gem that has come on the market has been named according to a simple convention. Though I am no fan of the ite word it has worked. Tanzanite, tsavorite, spessartite have done the job. With the new copper bearing Mozambique tourmaline a slight change is required. Since a mineral named cuprite already exists, cuprian as in cuprian elbaite tourmaline is the proper name.

We don't need lab gemologists to get into aesthetics or connoisseurship, areas for which they have not been trained. We don't need to exclude copper bearing stones from any source. We don't need another scandal. We don't need to confuse consumers. Try to explain the whole Pariaba thing and you will confuse buyers and confusing people is not a good way to market gemstones. We do need to knock of the BS.

Some say its too late, its a done deal, to that I say, nonsense! We all know that the naming of this gemstone is the result of a cynical and very well orchestrated attempt on the part of a group of dealers to hijack and build a marketing campaign on the good name of a very rare gemstone and we need to do it right.








Learn the truth about how tourmaline, padparadscha sapphire and other fine gems are graded and priced!

Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.

“Wise is a renowned author... He’s
done a marvelous job of this first book, monumental work, a tour de force...My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Only $35.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com


Saturday, October 13, 2007

Tourmaline: Copper, copper, whose got the copper?



You can't smell it, you can't taste it, you can't see it but its presence or absence can make a difference of tens of thousands of dollars in the price of a tourmaline. What is it? Copper!

By Richard W. Wise

©2007



In late 1990 copper bearing tourmaline from Paraiba first entered the market. In 1991 I wrote an article for
Colored Stone "Tourmaline, A Modest Proposal" in which I predicted that just as Paraiba had established a tourmaline aristocracy, inevitably stones that exhibited the light to medium saturation and hue similar to Paraiba stones would escalate in price. What I did not anticipate and could not predict was the discovery of Paraiba-like-copper-bearing- tourmaline in Nigeria and Mozambique. (Pictured above left 0.88 Paraiba tourmaline from Brazil from the R. W. Wise collection.)

Prices have, indeed, escalated and the hierarchy has been established. Regardless of the quality of the stone, genuine Brazilian stones from the Paraiba mining region will bring the highest prices followed by Mozambique followed by Nigeria.
(Pictured below right: 14.70 carat pair of pear shaped Mozambique cuprian tourmalines. Cutting Edge Award Winners, sold) Problem is, areas such as Afghanistan are producing vivid blue green non-cuprian gems that are superior to some of the cuprian stones. What determines the price, beauty, oh no, its all about the copper. We have become inured to such absurdities in the ruby, sapphire and emerald markets but Virgina its only a tourmaline! (pictured below left 3.97 carat Afghan non-copper bearing blue tourmaline from the R. W. Wise Collection)

So at every booth in Hong Kong showing a pretty blue green tourmaline. What was the first question? "Is it copper bearing?" Without asking that question is was impossible to price the stone.


Staggering Prices Differentials:

Price differentials can be staggering. The 14.70 pair of pear shapes pictured above right are certainly the finest of the Mozambique stones yet they sold at a price that was less than half what a comparable, if you could ever find a comparable, pair of Brazilian Paraiba stones would bring. Stones that compare in beauty but are not copper bearing bring hundreds of dollars while copper bearing look-alikes command prices into the low thousands of dollars per carat.

Whats New on our website:

Still haven't given up my day job. Just finished uploading a number of new pieces to our online catalogue. Several new tourmalines plus sapphires and some lovely new and antique jewelry pieces. www.rwwise.com




Whats a buyer to do?

Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.


“Wise is a renowned author... He’s
done a marvelous job of this first book, monumental work, a tour de force...My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise's masterpiece."

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and ... pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Only $37.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com