Important Note: The author: Vincent Pardieu is an employee of GIA (Gemological Institute of America) Laboratory Bangkok since Dec 2008. Any views expressed on this website - and in particular any views expressed by Vincent Pardieu - are the authors' opinions and do not necessarily reflect the opinions of GIA or GIA Laboratory Bangkok . GIA takes no responsibility and assumes no liability for any content on this website nor is GIA liable for any mistakes or omissions you may encounter. GIA is in particular not screening, editing or monitoring the content on this website and has no possibility to remove, screen or edit any content.
We are gemologists (gemmologists) sharing a passion for gemstones, gemolology (gemmology), gem people and traveling.
You will find in this website gemological expedition reports and some studies of gemological interest.
Visiting many gem mining areas we saw that people in remote mining and trading areas have difficulties to access to gemological publications. As today the Internet can be accessed in most of these gem mining areas and trading centers, the author started to build this website to give gem people living there the opportunity to see the result of the gemological expeditions they were associated in. It is a way to thanks them for their time and collaboration and to help them to get access to more gemological information.
At the same time the author hope that these expedition reports will please the people from consuming countries interested in gemstones and fascinated by their mysterious origins. Our purpose here is to help people facing difficulties to get quality first hand information about gems and their origins to get the information they need through this website and its links.
With our field expeditions to gemstone mines and gem markets around the world, we intend also here to share our passion for photography, gems and our fascination for the work of the "Gem People" bringing gemstones from the ground to magnificent jewelry.
From the gems external beauty to the intimate beauty of gemstone inclusions, from gem lore to the mines, the people and the landscapes gems origin from, we expect to share with you our passion for gemstone beauty.
We also invite you to join us on some gemological forums we are active in as they are convenient tools to get rapid answers to your questions as they are regularly visited by many other passionate gemologists, jewelers, hobbyists and professionals willing to learn more and share their knowledge about gemstones.
Index page: Vincent Pardieu's Blog
About the Author
About me : How did a countryside Frenchman became a "Shameless travel addicted gemologist"? ( Under construction)
Sep. 2005: Madagascar with Richard W. Hughes and Dana Schorr (Will be available one of these days...)
Summer 2005: Gemological expeditions to South East Asia (Vietnam) South Asia (Sri Lanka) and East Africa (Kenya, Madagascar and Tanzania) with J.B. Senoble and Tanguy Lagache with the support of the AIGS, the ICA and the Gubelin Gem Lab:
- Introduction to AIGS/ICA/Gubelin Gem lab 2005 Expeditions
Special THANKS for their support for our field expeditions since 2005:
about gems, gemology, field expeditions, studying gemology, minerals, jade, pearls or jewelry? We recommend these FORUMS where the author is contributing:
Do you want to STUDY GEMOLOGY?
Here are some recommended institutes where the author studied gemology in Thailand ... and was happy about his investment!
For those willing to go further after their gemological studies: Recommended Advanced Gemological Courses:
To finish here are some BOOKS about gemology the author have read and appreciated and would like to recommend to people willing to learn more about gemstones, gemology and the places where gemstones are found:
The ruby deposit in Montepuez was discovered during spring 2009 (see our GIA Mozambique expedition report). Rapidly many rubies from that new location were seen in Bangkok, Thailand. First we saw at GIA Lab Bangkok many unheated rubies but then more and more heated rubies. Unlike rubies from the Niassa deposit that were commonly seen treated using lead glass, these rubies were treated using some flux assisted heat process.
Dont get us wrong: It is not what we can really call a new treatment:
Flux healing using borax and silica is going on for nearly 20 years with rubies from Mong Hsu (Burma) and rubies from other deposits (usually marble type like Vietnam, Afghanistan, Tajikistan, Kenya, Tanzania,...) But the treatment is now performed also on rubies from the new deposit in Montepuez, Mozambique (which is not a marble type deposit). Usually what lab gemologists used to see with flux healed Mong Hsu rubies where healed fissures and sometimes glass filled cavities, but most of the time the stones were cleaned with acid before to be send to the lab and thus there was no glass filled cavities.
The new thing is that most of the flux heated rubies from Mozambique which were submitted to the GIA labs recently in Carlsbad, New York and Bangkok were obviously not cleaned with acid and has some large fissures filled with glass or partially healed and partially filled with glass (as the healing was obviouly far to be complete):
"Glass filled and healed fissure in Mozambique ruby"
On the right part of the photo taken using a microcope under 40x magnification and using dark field illumination, we can see a curved vertical line on the right side of the photo, on the top. It is the area where the fissure reaches the surface of the ruby. Note that this line is continuous. It means that the fissure is not healed. Close to the surface, the fissure is filled and it is possible to see inside the fissure some strait lines that are in fact devitrification features and small round features (in fact gas bubbles). Deeper inside the fissure (on the left side of the photo) we can see some fingerprint like designs first something like honey combs, then something more like a fingerprint design. It is the area deep inside the fissure where some healing was taking place.
To illustrate the fact that we are not really facing a new treatment, it is interesting and useful to remind and study carefully the excellent diagram published in 1998 by Prof. H.A.Hänni (reproduced with permission). Prof. H.A.Hänni was trying to explained what was going on inside these fissures during the flux-assisted heat treatment process:
"Flux assisted healing process by H.A.Hänni (Reproduced with permission)"
It is interesting to see that Prof. Hänny already saw devitrification features in surface reaching lass filled fissures during the 1990's in the case of rubies heated with flux (nothing really new in this treatment then...):
- In "D. after possible devitrification" we can see that the surface reaching area is filled with glass, with gas bubbles and devitrification features (it is exactly what you see on the inclusion photo in this blog) but we can see also that after D, there is E (logic...):
- "E. after cleaning by surface-etching": Flux healed rubies were usually cleaned and the glass was removed before the stones to be released in the market.
This last step in the process was obviously not performed in the case of the stones which were recently submitted at the GIA labs as we saw commonly that glass was still present in some surface reaching fissures. This is the new thing and the issue here:
- If the fissure is healed, then it is closed by recrystalization of ruby (synthetic ruby) and thus the final product is stable.
- Now if it is just filled, the durability of the final product will depend on the durability of the filler...
As such stones with healed and also glass filled fissures were becoming more commonly submitted at the GIA labs, at the end of March 2010, the GIA gemological laboratories in Carlsbad, New York, and Bangkok started to issue reports disclosing clearly the presence of these filled fissures in addition to the healed fissures. The reason is that glass (with lead or without lead) is much less durable than ruby and glass as a filler is likely to get damaged by chemicals, heat or abbrasion dparticularly during the stting or jewelry repairing process.
Thus it is important that the presence of such filler is disclosed to the consumer.
To get more details about this issue and the research we dit at GIA, please read the following report:
Important Note: Vincent Pardieu is an employee of GIA (Gemological Institute of America) Laboratory Bangkok since Dec 2008. Any views expressed on this website - and in particular any views expressed by Vincent Pardieu - are the authors' opinions and do not necessarily reflect the opinions of GIA or GIA Laboratory Bangkok. GIA takes no responsibility and assumes no liability for any content on this website nor is GIA liable for any mistakes or omissions you may encounter. GIA is in particular not screening, editing or monitoring the content on this website and has no possibility to remove, screen or edit any content.