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 "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 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. Adolph Piretti, 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 Piretti’s test samples had been
altered by diffusion. (photo left: Gemology 101, a natural
crystal cross-section: pink color zone caused by concentrations of
Mg. in the center of the crystal. Similiar images exist in the
literature going back 150 years)
How Diffusion Works:
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
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.
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,
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 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
Secrets Of The Gem Trade: