Gemstones & Pearls:Gemology
Groom Gematrat makes it easier to identify what lurks in your emerald
Determining clarity enhancement in emeralds has just become easier.
Groom Gematrat, the New York City company that introduced a new epoxy
resin filler last year, has added a tracer that will make the material easier
to identify when it is used to enhance an emerald's clarity.
There's Only One
The tracer is present only in Groom Gematrat treatments and isn't a factor
in determining any of the many other emerald treatments, including cedarwood
oil (which has been used for decades) and other epoxy resins (of which there
are several thousand kinds).
There are so many treatments, in fact, the Gemological Institute of America's
sophisticated laboratories list only "evidence of clarity enhancement"
rather than determine exactly which one it is.
Cap Beesley of the American Gemological Laboratory in New York City says
making such distinctions isn't hard. His reports currently list and identify
"Opticon-like" resins and cedarwood treatments.
Arthur Groom of Groom Gematrat agrees with GIA that without conclusive
identifiers for every form of treatment, it's unfair to distinguish any.
Various oils and epoxy resins have different life spans, different optical
effects and different durabilities. But Groom wanted to make his treatment
as identifiable as possible so jewelers would have no doubt.
The treatment was already identifiable because of its lower refractive
index than any other known resin. But now the addition of the tracer will
authenticate the filler as Groom Gematrat. It consists of microscopic uniquely
striped particles of a registered material that doesn't obstruct the clarity
or durability of the treatment. Lab technicians can quickly identify the
treatment with 120X magnification, says Groom. He hopes it soon will be
identifiable under 30X to 60X magnification, making it even easier for jewelers
"The tracer particles also have a unique fluorescence pattern under
short-wave ultraviolet light," he says. No pictures of the characteristic
particles or the fluorescence patterns were available at press time.
Groom also updated his technology for the cleaning and infilling process
at his lab. A new- generation machine speeds the infilling process by 70%.
"We have learned a lot about the efficiency of vacuuming, the spread
of the resin within the emerald and effects of various resin mixes,"
he says. "We've learned how different emeralds behave under different
The Groom Gematrat pro-cess applies controlled low heat in a sterile
environment the heat is no stronger than an emerald would experience
during the cutting process. The process prepares an emerald for the vacuuming
and subsequent infusion and even distribution of filler.
Groom says emeralds re-spond differently depending on the nature and
size of the inclusions. When selling a clarity enhanced emerald, it's important
to tell consumers how rare it is to find an untouched gem.
"I love to defend the concept of an unenhanced emerald," he
says. "But it is interesting to consider that a fine gem emerald that
requires no enhancement is rarer than a pink diamond."
by Robert Weldon, G.G. Copyright © 1998 by Bond Communications.