Part of our ongoing research into the undisclosed treatment of gemstones in Thailand!

Early on in our tourmaline research we started seeing very unusual features of blue material baked onto and into blue and green tourmalines. As always, the geographical source of these tourmalines was mixed throughout the world, but the common denominator for all was that they came from gem dealers located in Thailand . And once again, the tourmalines that we obtained direct from the mines of these countries showed no indication of this anomaly… saying to us once again that something strange is being done to tourmalines in Thailand and not disclosed to the consumers. It’s enough to give us The Tourmaline Blues.

Rather than go into a lot of rhetoric on this, we believe as always that the images will speak for themselves. Therefore below is an overview of a few of the tourmalines we purchased from Thai dealers that show this very strange blue material baked onto and into the tourmaline crystals. While certain members of the LMHC continue to go about the task of proving that all of this is just due to heating and nothing more, we have to challenge this notion when we see the following images…

Notice the image above. This was one of the first we encountered that said something was amiss. It was the first of scores of these stones we have found and continue to obtain from Thai dealers. Below you see this stone in higher magnification showing how this blue material baked into the tourmaline crystal and caused unusual blue coloring in the stone.

Perhaps most interesting is that all of these stones show this strange blue material on the “C” axis of the stone, with the coloring traveling down the crystal growth structure.

In stone after stone purchased from Thai dealers, we found this same neon blue coloring baked onto and into the "C" axis of the tourmaline crystals, with varying features extending into the gemstones.

In the case of the tourmaline crystal above, the original lavender color of the crystal is very apparent. However there is an unusual blue green color at one end, and the diffused blue color extending into the crystal from the other end with blue blotches throughout the crystal length.

In stone after stone we found the same unusual blue coloring cooked into the "C" axis of the stone.

In large parcels of cheaper rough we found yet more of these same blue features running through the stones. These do not follow the crystal growth structure as would be expected for tourmaline colors, but rather is random and concentrated along weaknesses in the crystal as would be expected for some type of artificial coloring effort.

Under high magnification it is possible to see this blue coloring agent penetrating into the tourmaline crystal.

And perhaps most important to this is the faceted tourmalines we have purchased from Thai dealers that contain the results of this treatment. Below are two views of a 3.20ct cushion cut “Paraiba” blue tourmaline purchased from a Thai dealer last year at the GJX show in Tucson . These are taken in the notorious ISG Dixie Cup Immersion cell. Again, the images speak for themselves.

In spite of their ongoing efforts to counter our previous reports, it is going to be extremely difficult for the members of the Lab Manual Harmonization Committee to come up with a report stating that this blue treatment is due solely to heating. The picture located to the upper right says otherwise to us on its face. The LMHC members are responsible for the industry confusion regarding tourmalines since it was the LMHC that is responsible for these artificially colored tourmalines to be sold as “ Paraiba ”….a complete disaster for the industry.  And litigation on this is still a strong possibility from several directions against the LMHC for this fiasco.

Currently we are receiving calls regarding a study going on at the GIA Thailand regarding tourmaline treatments that exemplifies this whole situation. For while it appears to be a large study done by the GIA, there are facts at play that have not been said.

As a result, we have a Thai based gem lab, using Thai supplied specimens from their local Thai friends, to do a study to prove that tourmalines sold in Thailand are not treated.

That pretty well sums up how things are going at this point regarding the LMHC studies on this topic. I guess the LMHC members are now going to start publishing studies on blue treatment features in tourmalines. But we need to inform them that there is much more we have not published. We’ll let that be a surprise for them.

Or… the LMHC can put an end to this absurd use of the term “ Paraiba ” for these treated tourmalines that should not even be in the same room with true Brazilian Paraiba Tourmalines.

Robert James FGA, GG
President, International School of Gemology

©2009 International School of Gemology. ALL RIGHTS RESERVED   All images are taken using the ISG Student Reference Collection of gemstones in the ISG office.  This article and the images herein have been reprinted in entirety by written permission of the ISG for publication on Nice Ice.  The statements and opinions made herein are that of the ISG and are not necessarily the opinion of Nice Ice, Inc.