Category Archives: Alta Lighona

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

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

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 cast 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 "crud 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 by 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

Tourmaline: Copper, copper, whose got the copper?

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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

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

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

Mozambique Cuprian Tourmaline, Part III

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Mozambique Cuprian Tourmaline, Part III

Purple Cuprian; A dilemma:

By Richard W. Wise, G.G.

“I know what you’re thinking. Did he fire six shots or only five? Well, to tell you the truth, in all this excitement, I’ve kinda lost track myself. But being as this is a .44 Magnum, the most powerful handgun in the world, and would blow your head clean off, you’ve got to ask yourself one question: Do I feel lucky? Well, do ya punk?”

Clint Eastwood

As tourmaline aficianados know, there are few truly rare colors of tourmaline. A pure yellow without a stong green secondary hue is quite rare and I have never seen a true violet but until recently, purple was the one spectral color that absolutely did not exist in tourmaline. Yes we had purplish reds but until last year when the Alta Lighona tourmalines from Mozambique entered the market, never a stone with a purple primary hue. (pictured above: 15.5 carat purple Mozambique cuprian tourmaline courtesy Pala International)

In early 1989 when the first curpian tourmalines from Paraiba appeared in the market in Brazil some were sold unheated. Most of these stones were a dark toned greenish “sapphire” blue, a “Thai sapphire blue” to be precise. In those days, blue was the most expensive, elusive and sought after color in tourmaline. Rumors whispered of a pure blue gem that was reputed to rival the finest in Burmese sapphire. This was the holy grail of tourmaline. I recall holding on to one parcel of natural dark blue Pariaba for several years before I burned them just in case the demand for the medium electric blue proved to be a passing fancy. Well, as we know it did not and when I finally did heat it, the result was a half dozen pure medium toned visually pure Carrribean blue gems that I sold at a substantial profit.

Since that time I have seen many examples of blue tourmaline including the famous Manoel Mutuca (described by Proctor as “sapphire blue” see Gems & Gemology, Spring 1985, p.11)) and Santa Rosa material but none (at least so far) with a true pure blue hue. Blue tourmaline always has a distinct greenish secondary hue which becomes quite evident when it is compared stone to stone with fine sapphire. Blue tourmaline can be exceptionally beautiful but it looks like tourmaline not sapphire.

To burn or not to burn or “Do I feel lucky? Well, do ya punk?”

With the entry of Mozambique curprian tourmaline we have a dilemma similar to the situation with the early Brazilian curprian tourmaline namely that some of the unburned material has a rich pure purple hue that reminds one of Siberian amethyst or fine purple sapphire. The difference is that unlike the rather dull greenish blue unheated Paraiba, this stuff is beautiful,

The Mozambique purples have a hue that is rich and pure. So, to burn or not to burn, that is the question, according to both Gene Flanigan from Precision Gems and Josh Hall at Pala International, these deep purples are also the best candidates for the oven, they heat to a neon pure medium “Paraiba” blue.

Some dealers have chosen the obvious solution. If you want a pure purple but burnable stone they will charge the same price as for the neon blue.(pictured above: unheated cuprian rough from Mozambique). Pictured below is an exceptional 1.89 carat custom cut Carribean blue cuprian stone cut from the center piece of rough. After and before; the first image shows the cut stone before heating. The second image shows the stone after the heating process was completed. The stone, currently available for sale at www.rwwise.
com was cut by Gene Flanigan a very talented lapidary artist from upstate New York. (Images courtesy Gene Flanigan: www.precisiongem.com)

Will purple tourmaline go the way of fine star sapphires that hardly exist anymore because they can be burned and faceted? I don’t think so, some of the fine purples simply possess problematic inclusions that make them risky candidates for burning. I found an 8.19 carat oval, a lovely example of Mozambique purple on my last trip to Asia. This stone faces up clean but under magnification shows long growth tube inclusions and cannot be burned. It is out having its picture taken and will be posted in a later blog. Logically purple cuprian tourmaline will have a two track price structure. Stones with a high degree of clarity under the loupe will sell for prices that may be double that for stones with certain types of inclusions whether visible or not.

Bits and Pieces:

I get lots of emails. Don’t think I’m not grateful. Every once in a while a real interesting one comes through the mailbox. take this on:

Position Available:

Dear Mr Wise,

We are Stargate, diamond trading division of Ebenhaezer Bank Consulting Group of Belgium, operating in thirty countries worldwide. We have read your blog regarding the appraisal of stones by qualified experts. We have constant need of qualified gemologists, expert in assessing ROUGH DIAMONDS, and have great difficulty identifying where they can be located.

We offer good working conditions, contracts, and a fair remuneration.

A special need has arisen in Bangui, Central African Republic, where we are currently (this week) accepting a large consignment. We require the services of a qualified gemologist, expert in rough diamonds, to assist our team there.

Would you be kind enough to assist us at your earliest convenience?

Yours sincerely,

Lucilla Arioti

Global Client Relationship Manager, EMEA

Stargate,

a division of Ebenhaezer Bank Consulting Group

Telephone: London +44 207 870 5389

I am not familiar with Stargate but believe the lady is serious. She even called and left a message on my machine. So if you are a gemologist in search of adventure give Lucilla a jingle. This time next month you could looking at sparklies and sipping pina colodas in beautiful downtown Bengui. As for myself I’d love to go along but I can’t give up my day job but when you get there be sure to drop me a line and oh do be sure to take along a flack jacket.

New Site with excellent online library of inclusions:

Got an email from a French gemologist: Marie-France Boursier-Brard. Ms Boursier-Brard has developed an excellent site with online images of inclusions. The site is quite comprehensive and well organized. Just click on: www.gemmes-inclusions.com

Check out my book Secrets of The Gem Trade; The Connoisseurs guide To Precious Gemstones: www.secretsofthegemtrade.com.

Now at 30% off just $27.95

“This book takes a much-needed sledgehammer to the industry’s conventional wisdom about what makes a gemstone precious, and in the process builds a solid foundation for anyone who wants to understand the true beauty and value of gemstones.”

Morgan Beard
Editor-in-Chief Colored Stone Magazine

Mozambique Cuprian Tourmaline: Part II; Beyond the hype