The study is about the treatment using flux (in this case borax and silica) of rubies from the new deposit near Montepuez in Mozambique.
Since the end on 2009 we have started a collaboration with a Thai burner working on the heat treatment of this material.
Also at about the same time we started to see in our labs (in New York, Carlsbad and Bangkok) some flux heated rubies with fissures only partially healed. The unhealed fissures were filled with glass. No lead was found in the glass filling these wide fissures, nevertheless this is still a glass and thus this is a problem for the durability of the stone as glass (containing lead, bismuth or not) will get damaged much more rapidly that ruby as it is more sensitive to chemicals, heat and abbrasion.
At the end of March 2010, as such stones were becoming more common, we have decided to add a special comment on our reports for such cases.
For more details, I invite you to download and read the following study:
The views expressed here are V. Pardieu’s opinions and do not necessarily reflect those of GIA Laboratory Bangkok (http://www.giathai.net)where he is an employee since Dec 2008.
Joined: Thu Aug 20, 2009 10:36 am Posts: 118 Location: New York
Hello Vincent, a nice piece of work. For those readers who may not already be aware of this material, this "latest ruby treatment" has been entering the trade in large numbers for about 1 year now. How to disclose this material has been a major concern for the industry. AGL released last week its initial findings and the disclosure wording that we apply for the two main types: i.e. those rubies where predominantly fissures have been healed and those rubies that possess the dual characteristics of fissure healing and glass in-filling. Our release and extra information may be found on our homepage at www.aglgemlab.com
From what I understand, the treatment by itself is not really new, it seems that this is more or less the same treatment (Flux-assisted heat treatment) performed on Mong hsu rubies for nearly 20 years. Nevertheles what is new is possibly the ruby material (From Montepuez, Mozambique) used in the stones we studyed presenting these features.
In the case of Mong Hsu flux healed stones, most of the time the issue was about glass filled cavities more than glass filled fissures. Here on the other hand we see commonly glass filled fissures, which was not common with the Mong Hsu material. This is possibly due to the fact that the Montepuez ruby material, which looks to be the material with these issues, has its own specificities and may be the treatment parameters should be adjusted...
Most of the flux healed stones (from Mong Hsu, Vietnam, Afghanistan,...) send to the laboratory in the past were usually cleaned with acid before to be submitted to the lab. This is obviously not the case with many stones we saw more and more regularly since Winter 2009.
Thus we have decided about 2 months ago to adapt our nomenclature to this specific issue.
It seems that AGL and GIA have a similar approach on that issue, which is nice.
The views expressed here are V. Pardieu’s opinions and do not necessarily reflect those of GIA Laboratory Bangkok (http://www.giathai.net)where he is an employee since Dec 2008.
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
VERY informative report Vincent, WELL DONE!!!
compliments to mr. Thawatchai Somjainuek too, hope that more burner will follow soon his collaboration path..
Joined: Wed Feb 25, 2009 5:53 pm Posts: 175 Location: Toronto
Wow.. great article! Thank you for loving gemology enough to provide all of us with a wealth of information!
Heh, this is like you're own private forum! Every non-archived thread was started by you! It says something about your research (and it says something good I think!).
Wow.. great article! Thank you for loving gemology enough to provide all of us with a wealth of information!
Heh, this is like you're own private forum! Every non-archived thread was started by you! It says something about your research (and it says something good I think!).
You are welcome.
LOL, It is not really a private sub-forum... everybody is welcome to post here. It is just that it happen that I'm (among other things) the webmaster for www.giathai.net and thus I'm usually very well informed when we put a new study online there.
As I'm visiting regularly this interesting forum, I try not to forget to invite people in this forum to go to read this research reports. But this is very non-official, of course.
The views expressed here are V. Pardieu’s opinions and do not necessarily reflect those of GIA Laboratory Bangkok (http://www.giathai.net)where he is an employee since Dec 2008.
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
Hey Tresh,
thresh wrote:
Wow.. great article! Thank you for loving gemology enough to provide all of us with a wealth of information!
This is the main reason that pushed our Admin team to develop a special area where all the outstanding reports released by Vincent and his GIA collegues can be collected and commented without the risk of spreading them in other sections were they could be easily moved in older pages as the new contribute are added.
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