Thanks and disclaimer:


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.


About FieldGemology. org

This website is home for "Shameless Travel Addicted Gemologist" Vincent Pardieu (B.Sc., GGA, G.G.). Vincent is "Supervisor, Field Gemology" at GIA Laboratory Bangkok. He is a gemologist specialized on "origin determination of gemstones".
This is also home for Vincent's regular traveling companions: David Bright, Jean Baptiste Senoble, Richard W. Hughes, Guillaume Soubiraa, Walter Balmer, Michael Rogers, Kham Vannaxay and many others like recently: Philippe Ressigeac, Oliver Segura , Flavie Isatelle and Lou Pierre Bryl.

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.


Website Map


Index page: Vincent Pardieu's Blog

About the Author

About me : How did a countryside Frenchman became a "Shameless travel addicted gemologist"? ( Under construction)


Contact the author:


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Popular Articles

"Tsavorite, an Untamed Gem" with R.W.Hughes, first published in ICA's InColor (Winter 2008)
"Working the blue seam" The Tanzanite mines of Merelani with R.W.Hughes first published on
"Spinel, the resurection of a Classic" with R.W. Hughes, first published in ICA's InColor (Summer 2008)

Gemological studies

(Apr. 2009) "Sapphires reportedly from Batakundi / Basil area" a preliminary study about unusual sapphires we saw at GIA Laboratory Bangkok
(Mar. 2009) "Rubies from Niassa province, Mozambique" a preliminary study about rubies we saw at GIA Laboratory Bangkok
"Lead glass filled rubies" :
First published on AIGS Lab Website (Feb 2005)

Expedition Reports

Autumn. 2009: GIA Field Expedition FE09: Rubies from Mozambique. (pdf file)

May. 2009: GIA Field Expedition FE08: Melos and their pearls in Vietnam. (pdf file)

Dec. 2008 and Feb-Mar. 2009: GIA Field Expeditions FE01 and FE04: Rubies and sapphires from Pailin, Cambodia. (pdf file)

Aug. 2008: Sapphires and Tsavorite from the south of Madagascar with the AFG (Association francaise de Gemmologie) : Available soon...

Apr. 2008: Expedition to the new Winza ruby deposit in central Tanzania with Jean Baptiste Senoble and the support of the Gubelin Gem Lab

October 2007: Gemological expedition to East Africa (Kenya and Tanzania) with Richard W. Hughes, Mike Rogers, Guillaume Soubiraa, Warne and Monty Chitty and Philippe Bruno:

Summer 2006: Expeditions to Central Asia gem wealth with Guillaume Soubiraa and the support of the AIGS, the ICA and the Gubelin Gem Lab:

Oct. 2005: Colombia by J.B. Senoble

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:

- Feb. 2005: A visit to Thailand, Cambodia with the AFG (Association Francaise de Gemmologie) (under construction)

- 2002-2007: Expeditions to Pailin (Cambodia), Chanthaburi Kanchanaburi (Thailand) Houay Xai (Laos) Mogok, Namya (Burma) (under construction)

- 2001: Expeditions to Namya, Hpakant and then Mogok with Ted and Angelo Themelis and Hemi Englisher (under construction)

Find our blogs using the following Keywords:

     black star sapphire
     Bo Rai
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     Di Linh
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     Field Report GIA
     Gemological study
     Ha Long
     Ha Long Bay
     Houay Xai
     Khao Ploy Waen
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     lead glass filled ruby
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     Richard W. Hughes
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Find our photos using the following Keywords:

     Bai Lai
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     Minh Tien
     pearl farm
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Discover fieldgemology newsletter:
(Currently under "hibernation status"...)

Number 01: Sept 2006
(I know: it was long time ago...)



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

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:




Creative Commons License

The photos and articles on are licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.
Feel free to use the photos and articles with links and credits. No commercial use without permission.
All the best,

January 24th, 2012 | Keywords:Bosshart , gemology , Pailin Travel |
Blog Title: Georges Bosshart (19xx- 2012)

This post is not about one of the author expeditions or about an article he collaborated with, but it is about one friend, who was a great source of inspiration for the author's when he was still searching his way in gemology: I mean Georges Bosshart.

Last week while I was traveling to Sri Lanka I received the sad news that Georges passed away in Switzerland after a long and very courageous struggle with cancer. He was one of these persons that I would have loved to spend more time with. All my thoughts are today to the one he used to call his best treckking companion: His wife Anna.

The first time I met Georges Bosshart, it was in 2003. I was then working as a part time consultant for the AIGS laboratory in Bangkok, but I was mainly spending my time traveling to Burma to buy gems for my boss Henry Ho, the owner of the AIGS lab. Georges came to the lab while he was on an OPT (Off Premise Testing) mission for the Gubelin Gem Lab. On that occasion Georges was willing to use some of the advance equipment we had. For a young gemologist like the author, learning from such an experienced gemologist like Georges Bosshart was an occasion not to be missed. The contact with Georges turn to be extremely easy as we were sharing similar interests not only for gemology but also about traveling to gem mining areas (particularly in Burma).

"Swiss gemologists in Pailin, Cambodia!"
Left to right Georges Bosshart, Walter Balmer checking heat treated sapphires at a sapphire burner place in Pailin, Cambodia"
Photo: V. Pardieu / AIGS, 2006

That first visit was quite brief as it took less than one hour, just the time to make few analyses. Few months later, on a another OPT, he contacted us again and this time Jim Mullen, the AIGS lab director, made an agreement with Georges Bosshart that in exchange of the possibility to use the lab advanced instruments, he would spend some time showing to the lab gemologists how to better use them. Thanks to that on that second visit the author had the privilege to be able to spend two full days in the lab with Georges Bosshart teaching him how to better use the EDXRF, the UV-Vis and the FTIR. Then as out contact was very good, we also spent a day looking at the samples I collected in Burma during my gemology studies and discussing about them, gemology and our experiences traveling to gem mining areas in Burma. Georges was one of the rare persons to have been able to visit not only the gem mines of Mogok and Hpahant but also the small diamond deposit near Momeik.

These three days working on instruments and looking at stones besides Georges Bosshart were a major event for the author as Georges passion for gemology was very contagious: For the young gemologist still searching his way that I was then, his comments and advices were very encouraging and inspiring. After discussing with Georges, I had the great feeling that I was doing the right thing. Georges also convinced me that I could do much better because I had the unique opportunity to be a young gemologist based in Bangkok: It was then much easier for me to get some interesting samples to study visiting the numerous gem mines and markets located around Bangkok that it had been from him in his young days based in Switzerland. He encouraged me to continue going to the field in order to collect seriously reference samples, and then study them very seriously as he said it was the best way to get more knowledge.

In the weeks and months following Georges visit, I spent more and more time in the lab. I also started to travel more regularly to gem mining areas near Chanthaburi, Kanchanaburi and Pailin in order to collect reference samples at the mines, study them back at the lab and then I also started some heat treatment experiment with the help of local Burners in order to see what had changed in the samples after heat treatment.

My boss Henry Ho noticed then rapidly my increasing interest for gemology and soon accepted that I was somewhere lost for the gem trade. In September 2004, a little bit more than one year after meeting Gorges Bosshart for the first time Henry Ho proposed me to become the Director of the AIGS Laboratory. I accepted with pleasure and passion...

In December 2006, few weeks before leaving Thailand to work as a gemologist for the Gubelin Gem Lab in Switzerland I had also the pleasure to welcome again in Thailand Georges Bosshart with his wife Anna and two other Swiss friends: Walter Balmer (who had just left the Gubelin Gem Lab to start a PhD at Chulalorkorn University in Bangkok) and Michael Kremnicki from SSEF. We went on a field expedition to the sapphire mining areas near Chanthaburi and then to the ruby and sapphire mines near Pailin. It was a real pleasure to spend some time with Georges, this time in the field, help him to visit Cambodia and use that occasion to thank him for these very inspiring days we spent together in Bangkok. Again we had some great discussions about some of his favorite subjects like green minerals or Burmese diamonds.

"Georges Bosshart at the IGC in Arusha in Oct. 2009 with a large crystal of Tanzanite. If he was already struggling against cancer, his passion for gems was still vibrant, fresh and contagious."
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

I had the pleasure then to meet again Georges and Anna at their home in Switzerland for a great diner where they introduced me to Alan Jobbins, who studied the Pailin ruby and sapphire mining areas in the 1970's. We also met at few more occasions in Bangkok and in Tanzania for the IGC in Arusha in 2009. Again his discussion was very inspiring.

Georges was indeed somebody very special: It is not easy to describe him with words. He was of course a very complete gemologist and a true gem connoisseur with a very extensive knowledgeable about diamonds, pearls, jade and colored stones. He was an expert on instrumentation and a great lab gemologist. But that was not all: He was also an experienced traveler and one of the most experienced gemologists regarding traveling to gem mining areas. But most of all he was also a very sincere, passionate, and meaningful man, a great man who enjoyed sharing his tremendous knowledge with young people, speaking true to them mixing humour and sarcasm to the perfection: A very rare man and a truly a great source of inspiration for young gemologists like the author.

Georges, it was a real pleasure to have been able to meet you and to have had the privilege to have spend few days around you. I would like to thank you here for all these inspiring moments and great advices that you gave me. If today I enjoy working as Field Gemologist at the GIA, I've to say that I own you a lot as you helped me to find my way and then to keep on the right track...

You will be missed for sure but be sure that you will remain a great source inspiration for all the people who had the pleasure to have met you.

All the best,

April 6th, 2010 | Keywords:Cambodia , Pailin , sapphire , ruby Travel |
Blog Title: GIA FE15: Apr. 03 - Apr. 04, 2010: Pailin, Cambodia

GIA FE15 (GIA Laboratory Bangkok Field Expedition 15): Apr. 03, 2010 - Apr. 04, 2010:


Each last Wednesday of the month, the GIA Laboratory Bangkok and the GIA Thailand School join their forces to organize events called the GIA Gemstone Gatherings at the Pan Pacific hotel on Rama IV road in Bangkok. The hotel is conveniently located just half way between the GIA Thailand School on Thanon Sap and the GIA Laboratory Bangkok on Rama IV road. It is each time a great occasion to attend a presentation of gemological interest and also to meet people active within the Bangkok gem trade, foreign gem merchants visiting Thailand, gemology students, etc. For the author it is all the time a good place to meet new people and old friends and to find good traveling companions for weekend expeditions to gem mining areas around Bangkok.


For more information about the GIA Gemstone Gatherings please visit the "news" page on GIA Laboratory Bangkok website. There you will find, details about the next event. Using the calendar at the bottom of the page you will also find written reports and photos of the previous GIA gemstone gatherings.


For the 34th edition of these GIA Gemstone Gatherings, the speaker was Vichian Veerasaksri, who spoke about CIBJO and its role within the gem industry. There I met again Jonathan Muyal, a young French gemologist who graduated last year from GIA Thailand. Jonathan was regularly attending the GIA Gemstone Gatherings since then and we had the occasion to exchange some words at different occasions. Jonathan Muyal has an incredible background as a former Thai boxing champion and a true gift for learning languages: He is fluent in French, English, Spanish, Thai and Japanese and has good basic in more than 5 other languages. As many others (including myself) he became interested in gemstones after spending nearly 10 years in another field (Professional Thai boxing for Jonathan, tour guide for me). Living in Thailand for few years, he came to logically to GIA Thailand to study gemology, get a diploma with a large international recognition and try to start something in relation with gemology. Jonathan was preparing a visit to Japan but had no plans for the weekend. We decided to visit Pailin in Cambodia for our first expedition together. A classic.


We left Bangkok early in the morning on April 4th with the bus while thousands of red shirts protesters were entering the city. First as usual we travelled to Chanthaburi, the gem city of Thailand we reached in about 4 hours. From there using a small songtaew we took the road to the Thai Cambodian border distant of about 50 additional kilometers. Pailin city is located 23 kilometers from the border. Nearly seven hours after leaving Bangkok we arrived in Pailin welcomed by some heavy rains... The region around the small city was green. Such a big contrast compared to 2 weeks ago where everything was dry and brown. Then gem mining was nearly reduced to zero due to the lack of water. Ruby and sapphire deposits around Pailin are secondary deposits. Gems are found from gem rich gravels that are washed. No water, no gem mining! Obviously during the last week rain was back and thus we had then good chance to be able to witness again some gem mining operation around Pailin. We nevertheless had to wait for Sunday to witness gem mining as on Saturday the author local contact and guide Votha Un was as many people in Pailin busy farming red corn. If gem mining can wait, in agriculture there is no time to waste when the rain has come... We met Votha for diner in our usual diner spot. There we could discuss about the next expedition we were planning to in few months to remote ruby mining areas located in the jungle south of Pailin. Of course we also discussed about the program for the next day: The visit at the morning gem market was looking promising!


On Sunday morning at 7 am we visited the gem market in order to take our breakfast, to get some fresh news about who was mining and where and of course to see some gems. For Jonathan it was a great occasion to study some interesting small rough sapphires and discover their inclusions.

(Gemologist Jonathan Muyal studying a parcel of sapphires in Pailin morning gem market that takes place each morning down the Phnum Yat temple.)
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

As local gem dealers started to gather around us we saw as usual some interesting stones both rough and faceted. Most of the stones we saw were small in size as it is common in Pailin. Nevertheless it seems that the 2010 gem mining season had a good start as we could see some interesting stones that, reportedly, have been mined recently.


(Votha presenting to the author a very fine Pailin blue sapphire about 5 carats and a nice ruby about 2 carats. The sapphire was reportedly mined few years ago around Phnum Yat while the ruby was very recently mined near O Beng village, few kilometers north of Pailin city)
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)


The author could see that once again the best way to see some good stones is to show some money buying a fine gem... Local gem dealers then realize two important things: You know what a good gem is and you can afford them. At that point some merchants might invite you to their place where they might show you some fine gems they usually don't bring to the market. To your surprise you might then find out that some people you were feeling that you knew well were in fact keeping some fine gems secret and for some reason that day they feel good to let you look at them and even take some photos of them... Funny!


Of course the inverse is also true: Start your day buying a synthetic or a piece of glass in front of everybody for the price of a natural gem at the Pailin gem market, then be sure that for the rest of the day and probably also for several weeks, you will see mainly glass and synthetics as nobody will dare to show you anything good.


That weekend we were lucky to experience the first case: After spending about one hour at the gem market we were invited by some of the most serious gem miners and merchant in Pailin to visit them. We had then the great opportunity to see some stones of a quality so far never presented in Pailin to the author since 2004. That was really an interesting day!

Of course that was not meaning that production had been recently excellent: Most of the stones we saw were old stones they were treasuring possibly for years. Studying their internal world with the author GIA Dark field loupe, we found out that there was nothing that would enable to sustpect that the gems were not indeed rubies and sapphires mined in Pailin as those with visible inclusions under 10x loupe had classic inclusions for pailin gems.

(Details on the same fine ruby and sapphire presented on the previous photo. Note in the background an interesting pear shape zircon that was also mined around Pailin.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

The author did not missed the opportunity to practice macro photography with his new camera. Things were obviously not really perfect particularly regarding colors. Anyway, it has to be expected and the author will have obviously to practice a little bit with this new camera before to get back the quality expected with the old one.


Most of the fine rubies and sapphires we saw were small in size compared to fine gems from other mining areas. Fine large gemstones are truly rare in Pailin but nevertheless there were some noticeable truly beautiful little gems: We could see a very fine and clean emerald cut blue sapphire about 5 carats displaying an even rich blue color. The stone was presented an unheated. Besides this fine gem, we could see many nice small rubies between 1 and 3 carats. Most of the rubies we saw were either heated displaying a deep red color, or unheated with then a distinct purplish secondary color. Besides these fines rubies and sapphire we could also see few interesting brown zircons.

(Rough and faceted Pailin rubies and sapphires. The rubies were reportedly mined near Bang Pra Lat village few kilometers from Pailin in the direction of the Thai border while the sapphires were mined around Phnum Yat volcano in the south of Pailin city. The largest faceted ruby is a little bit less than 3 carats. Most of the faceted rubies were probably heated while the rough stones still have the common purplish color of unheated stones.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

But we did not spent our week end just visiting gem merchant, after few hours we learned that one of the most important gem miners, known usually to mine rubies near bang pra Lat village had started few days ago a sapphire mining operation few hundred meters from Pailin city on the North of the Phnum Yat volcano.


We took the road to visit that mine and found out that he was working in partnership with a local farmer. The miner was providing the machines, was financing the whole mining operation including the rehabilitation of the land in exchange of 80% of the stones produced. The farmer was getting 20% of the stones produced. He told us that he was expecting that mining will be finished within 3 months and hopefully he will have enough stones to provide the capital he will need to turn the land into a fruit plantation and get enough to be able to wait for his trees to start producing something. In fact such practices where a gem miners and a farmer collaborate are very conservation friendly practices, as the land mined today will not became a wasteland. To the contrary gem mining can then provide to a poor farmer enough capital to improve his farm.

(Sapphire mining near Pailin using high-pressure water to turn the gem rich gravels into mud. The mud will be then processed using the fact that gems like sapphires, rubies and zircons have a higher specific gravity compared to non-gem material.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

The mine was similar to those we saw in the past: a team of about 10 miners was working on a hole about 6 to 8 meters deep which had been dig using an excavator in order to remove the overburden, the miners were then using high pressure water to turn the gem and gravel rich layer into mud. This gem bearing mud is aspirated to the jig where, using gravitation to his advantage, the miner was concentrating the sapphires in traps while lighter stones were taken away bu the water flow. At the end of the day the production will be carefully collected by the miner, his team and his partner (the farmer). That day sadly we had no time to wait to see the harvest. We had to return to Bangkok in order to be there in time for Jonathan to fly to Japan and for me to be at the GIA Lab Bangkok for a new week referencing the stones collected in the field and preparing the next field expeditions.


It was a again an interesting week end in the field. Full of surprises particularly for Jonathan but also even for the author even after nearly 20 visits to Pailin.

March 30th, 2010 | Keywords:Thailand , Chanthaburi , Kho Laem Sing , Cambodia , Pailin , sapphire , MJP Travel |
Blog Title: blog GIA FE14: Chanthaburi, Pailin and meeting the MJP.

GIA FE14 (GIA Laboratory Bangkok Field Expedition 14): March. 19, 2009 - Feb. 21, 2010:


Last week end with Tracy Lindwall, a gemology student from California sharing with the author a keen interest for both gemological and conservation fields, we decided to leave Bangkok to travel to Cambodia to meet in Battembang Stephen Bognard, the CEO of MJP, the Maddox Jolie-Pitt Foundation, a conservation and community development organization with a special focus on the Cardamom Mountains, the moutainous region along the Thai border linking Pailin to lSamlaut. On the way to Battembang, we decided to spend as usual some time in Chanthaburi and in Pailin in order to continue discovering these fascinating gem mining areas and their rich historical background. It was a week end full of surprises.


We left Bangkok to Chanthaburi on Friday evening and spent the night in Chanthaburi.


Chanthaburi (Thailand): The lion and my camera: On Saturday 20th 2010, early in the morning we left of guesthouse near the river to travel to Khao Laem Sing, the mountain located at the mouth of the Chanthaburi river. There we first found the scenic jungle covered Phairee Phinat fort, the small ruin that was more than 100 years ago a small fort defending the entrance of Chanthaboon port with two canons. There we found an old jungle chedi that was built after 1908 during the reign of Rama V as an independence monument to celebrate the end of the 10 years of French occupation of Chanthaburi. The area was desert, it was nice...


Down the fort is a small shipyard. We went to visit it in order to enquiry about our main goal: The famous lion rock which, like a majestic sphinx, seems on the drawings of Henri Mouhot a French traveller who visited the region in 1859 to keep the entrance of the Chanthaburi River. The rock was famous worldwide during the past centuries as before using planes to arrive in Thailand most travelers visiting the country then known as Siam where arriving by sea. Chanthaburi was known then as "Chantaboun" or "Chantaboon". The Chanthaboon lion rock was then a common and well-known symbol of the country. The region from Chanthaburi to Pailin was of some particular gemological interest. It was reported by several famous authors (Streeter, Bauer) as the world's most important sapphire mining area, both for the quantity and the quality of the gems produced at the end of the XIX century and probably a consequent number of sapphire of the jewelry from that period were mined in the region then called "Siam".


We could imagine that most of these sapphires, left probably the region and the country they were mined sailing on the Chanthaburi River and passing then near the majestic Chanthaburi lion of Khao Leam Sing before to leave Siam.


The lion was our objective on that Saturday morning. At the Shipyard we met its owner: Mr. Nuu a very friendly man who run a nice and remote home stay between the shipyard and the old jungle covered fort. He welcomed us, told us very interesting things the area and provided us a small canoe to be able to sail up to the famous rock. The water was quiet, but nevertheless the entrance of a river is not without dangers when you sail on a small canoe with a camera: While I was taking photos of the rock as small wave surprised me. I lost partially my balance and dropped my camera. My Nikon D300 felt into the sea. I had just the reflex to grab it before it to sink too deep in the salted water. Hopefully only the camera felt into the water and our 2 other cameras survived the short but hazardous marine expedition...

(Here is the last photo of my Nikon D300 camera associated with a drawing by Henri Mouhot, A French traveller who visited Chantaboun in 1859)
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010

Back on land we took the road to the Thai Cambodian border where our friend and local contact in Pailin Votha Un was waiting us. We drove then to together to Pailin. As usual in March, at the end of the dry season, the whole region was suffering from the lack of water the hills once covered by green jungle during the rainy season were now covered with ashes. The destruction of the jungle and the forest is a major problem in Pailin region. In the south the Cardamon mountains were still green, but here or there we could see from the road several columns of smoke...


Pailin (Cambodia): Update about gem mining (March 20, 2010): We tried to find the ruby miner we met few weeks ago near Bang Pra Lat village but he was not working as there was not enough water to wash the gem rich ground. Votha took us then to the only place where we could possibly find gem miners during the dry season: Near the river. It was getting late in the afternoon and in all the areas we inspected we found the stream deserted. At the end of the afternoon as we were not hoping to find any gem miner, on the way to Pailin city between the river and Ta Ngan Krom, we saw a mining pit. A miner was digging less than 5 meters from a house just near the dirt road we were driving on. Inside the vertical mining pit, which was less than two meters deep, we found a former Khmer rouge soldier. The man was over 45 years old and one of his legs was missing under the knee. Outside of the hole his wood leg was placed near the tree dominating the mining pit. Seated in the deep hole he was nevertheless very actively mining, filling baskets of river pebbles which were then taken out of the hole by another, yet younger, miner. Both of them were friendly and we started discussing about their work and their life mining gems near Pailin. The old war veteran working as miner explained that he lost his leg on a land mine during the war more about 20 years ago. As a former Khmer rouge soldier, he said that he was not receiving any money from the Cambodian government and had then no other choice than working hard to be able to survive. With only one leg, digging for gems was the best way he found to make some money to survive.

Few minutes after our arrival, a local Pailin gem dealer arrived at the mining site, obviously to buy the production of the day. Today was a different story, I was already there and the production of the old soldier was already in my pocket to become GIA reference samples. There was no problem, it was only about few small stones and the dealer and I knew each other for many years. We spent the end of the afternoon together around the mining pit looking at the production of the day, at what the dealer had collected during the past days and discussing about the life of the people mining sapphires around Pailin.

It was a nice. Then as suddently a heavy rain started we all left in a hurry.


(V. Pardieu discussing about sapphire near a mining pit with a Khmer miner and some local people farmer including the gem dealer financing the small mining operation (with the cap and the sun glasses)
Photo: Tracy Lindwall, 2010

We then drove to Pailin. We found that the small city was dusty with road works. Hundreds of workers were building around and inside Pailin the major road that will link Phnom Phen to Battembang and the Thai border through Pailin. Pailin will then probably not be anymore a small and remote village close to the Thai border but a small boomtown on a major communication axis.


On Sunday 21st 2010, as usual we started our day visiting the small gem market located down Phum Yat temple. There, around some tea and noodle soups each morning between 7 and 9 am most of Pailin gem dealers are gathering to discuss and trade gems. About ten dealers, gem cutters, and gem burners were present. After few minutes an important gem dealer of the region came to meet us. During the French colonial times his grand father and then his father were already gem cutters and gem merchants in Battembang.


On an old traditional brass plateau he presented us a very interesting faceted sapphire:


Sapphires of interest seen in Pailin: The blue sapphire we saw that day is an attractive dark blue coussin weighting around 10 carats. Its color could be described as an even deep dark blue with nevertheless the typical grey overcast commonly found on most large basalt related blue sapphires. The stone was very clean with as inclusions just few tiny crystals, their aspect suggest that the onwer was probably right to say that the stone was not heated. Something very rare in Pailin, where several gem burners are working.


If that sapphire was not the best blue sapphire I was given to see, it was far to be a bad looking stone and taking in consideration all its different aspects including its large size and exceptional clarity, it was probably the best stone the author saw in Pailin after nearly twenty week end expeditions since his first visit in 2004: In Pailin, fine sapphires over 10 carats are extremely rare, so rare that so far I never saw one. The largest fine Pailin sapphire I was told about from reliable source was a fine stone reportedly about 15 carats, but I could not get any details except that it was nice.

(A fine blue sapphire from Pailin associated with small pailin rough I collected the day before at the mines. The faceted stone, probably unheated, is about 10 carats and is the best faceted blue sapphire the author ever saw visiting Pailin since 2004)
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010


Back home I was thinking that if I had seen the same stone at the Bangkok Gem Show in a classic booth from a dealer in the middle of hundred other stones, I would have seen the gem in a very different way. I was not just enjoying a lovely stone, but it was also about the moment, the place, the people and the whole story. Enquiring about the origin of the stone with its owner, Votha and the crowd of dealers who gathered around us, I was told that the stone was found few days ago on the ground at the back of Phnum Yat, the pagoda covered volcano, dominating Pailin. Later I heard another story about another recent find on Phnum Yat volcano: A large sapphire was reportedly found in a piece of basalt weighting about two kilos. A 20 carats rough sapphire was reportedly broken from the basalt and sold separately. Nevertheless a large broken piece of sapphire crystal, weighting probably still around 10 carats, was still present in the piece of basalt (see following photo)


Was the 10 carats faceted sapphire the author saw in the morning the piece that was broken from the basalt? It seems that they were found at the same place at the same period... That would be a lovely story. The author was nevertheless not able get confirmation about it. Nevertheless, the following week end, on March 28th the author returned to see the stones and was then able to see them together and document them. The sapphire in the basalt has, like the faceted stone, a large milky area in its center. Their dark blue color was also quite similar but only a serious study in the laboratory will be able to find out if the faceted stone and the sapphire still in the basalt could have been in the past a single sapphire crystal. Even if we don't know yet if this could be the case, the following photo might nevertheless be of interest for readers.

"Sapphires reportedly from Pailin as faceted stone and as xenocryst in basalt"

(Another photo of the same faceted sapphire in association with the sapphire xenocryst in Phnum Yat basalt. The Phnum Yat volcano is known to be the source of Pailin blue sapphires. Such pieces of sapphire taken in basalt are not commonly found as in Pailin most sapphire mining is performed from secondary deposits resulting from the weathering of the basalts. This sapphire in basalt was the third the author was able to study in Pailin since 2004.)
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010


For more information about Pailin, please visit the GIA Laboratory Bangkok, "Lab Ongoing research - Field Reports Page" where you will find, among several other gemological expedition reports and gemological research pdfs, the following expedition report to Pailin:

Concise Field Report Vol. 01: Pailin, Cambodia: (Dec. 2008 - Feb. 2009) by V. Pardieu
"The Pailin gem mining area in Cambodia. It is a known source of basalt related rubies and blue sapphires since the end of the XIX century. This report provides an update about the current mining there and illustrates the way GIA field gemologists collect specimens at the source."


Meeting the MJP (Maddox Jolie-Pitt Foundation): After visiting the market we took the road to Battembang in order to meet Stephen Bognard from the MJP Foundation, it was the first time we met and we had a very pleasant lunch exchanging ideas and experiences. We spoke of course about conservation and gem mining. It was interesting to listen what was their experience in the region. In Pailin as in East Africa I was able to see that conservationists have some very similar problems. The main issue, there as in Pailin is the destruction of the habitats. Around pailin and samlot the region is still beautiful in the south of Pailin but in the north it is mainly dust and ashes. the whole are is as we could see at each of our visits is facing many threads. For more details, a visit to MJP website might be a good idea:


In 2003, Ms. Angelina Jolie created the Maddox Jolie-Pitt Foundation (MJP) an organization for the conservation of Cambodia’s endangered Cardamom Mountains. Its initial focus of its conservation work was on the protection of Samlaut National Park (Samlaut Protected Area), an area that contains most of the region’s biodiversity: forests, freshwater ecosystems, and endangered species...


We will meet again in the future and try to see if there is a way for Pailin and Samlaut rubies and sapphire to help to protect the gem that are the Cardamon mountains one of the last natural area in the whole South East Asia.


After lunch we left Battembang to return by road to Pailin, then Chanthaburi and finally we returned to Bangkok around midnight in order to be fit to return to work at the GIA Lab on monday morning. Back in Bangkok I got the confirmation that my camera and my lenses were beyond repair. I got also the confirmation that my insurance was useless in that case. That was a very costly week end but well, I will survive!

January 3rd, 21st0 | Keywords:Chanthaburi , Khao Ploy Waen , Thailand , Pailin , Cambodia , sapphire , ruby Travel |
Blog Title: FE10, Thailand and Cambodia: New Year's Day visiting ruby and sapphire mines near Chanthaburi and Pailin.

GIA FE10 (GIA Laboratory Bangkok Field Expedition 10): Dec. 30, 2009 - Jan. 02, 2010:


With two veterans of the recent expedition to East Africa: gemologists Jean Baptiste Senoble (France) and Lou Pierre Bryl (Canada) we decided to celebrate 2010 New Year's Day far away from the party crowds and close to both gems and nature. On December 30th 2009 we left Bangkok to travel to Chanthaburi, the former Chantabun of the XIX explorers and one of the most active gem trading centers in Asia.

The idea for that short week end field expedition was to get an update about sapphire mining around Chanthaburi and about ruby and sapphire mining around Pailin in Cambodia, at the same time it was a good occasion to travel with some new "padawans": Tracy Lindwall from USA and Neil Doohan from Switzerland, two fans of who contacted me after deciding to study gemology in Thailand as I did also few years ago.

Tracy was looking very motivated to help me on the "Conservation Gemology" project and during the next expeditions around Bangkok she will focus on such issues as ethical and conservation gem mining.

On December 31st we visited the sapphire mining area near Khao Ploy Waen and Ban Ka Cha few kilometers from Chanthaburi. The area was quiet but around ten mechanized sapphire mining operations were visible around the lovely jungle covered volcano and its old pagoda. If most operations were stopped during the New Year weekend, we could nevertheless see two mines in operation and speak with several miners. All the mines in the area are working to produce black star sapphires, some blue sapphires but the main production is yellow and green sapphires, which are later turned into bright yellow/orange sapphires (Locally called "Butsarakam") after heat treatment usually using the "beryllium" technology.

After visiting the lovely area around Khao Ploy rich not only with sapphire mines but also lovely houses and fruit plantations, we were joined in the evening by Neil Doohan, a young Swiss American studying gemology in Bangkok. After a great diner near Chanthaburi River, we decided to return to Khao Ploy Waen volcano to reach the old pagoda on its top and wait there for midnight to come.

At midnight, standing on the top of the volcano, which is the source of all the sapphires in the area, we could enjoy the fireworks all around in the plain... Simply nice!

(Sapphire mine near Khao Ploy Waen volcano, Chanthaburi, Thailand.

Note the different bassins built in order to return to the river only clean water.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009)

On January 01 2010 we left Chanthaburi and Thailand by road to Pailin in Cambodia, a small Cambodian city we like to visit regularly despite its bad reputation for land mines and malaria (July 2009 and more recent) as it is an interesting ruby and sapphire mining area not very far from Bangkok. Pailin is located just north of the Cardamon Mountains one of the most interesting and endangered ecoregion of South East Asia. For some background information about Pailin and its gems, please download the "Concise Field Report Vol. 01: Pailin, Cambodia" on

In Pailin we met our Cambodian friend and guide: Votha. With his help, we visited several small ruby and sapphire mining operations around the city. Mining was quiet as most of Pailin population was busy with maize harvests:

Near Bang Pra Lat, we could meet a team of five miners we met last year at O Beng. As last year they were mining rubies with a small old jig and some high-pressure water. During the last month they produced few small rubies including an interesting stone about 3 carats rough.

In another area near Suan Umpal we met two groups of old men mining sapphires with iron sticks in holes in an area that was mined by Thai companies during the "Khmer Rouge" period. Finally near O Ta Prang we met a man and his wife mining in the river for sapphires. Near them an 83 years old Cambodian woman living usually in California, and currently spending some holidays with her family in Pailin, was also enjoying searching for zircons and sapphires in the stream with one of her grand sons.

The visit was interesting as we could add to the GIA reference collection the daily production of the miners composed of several small rubies and blue sapphires.

Our main surprise was to see how the city had changed in just few months as the new road built by a Chinese company linking Battembang to the Thai border had reached Pailin. The new road and the fact that Pailin is became a full Cambodian province since December 28th, 2008 has turned the small sleepy village into a small boomtown.


(A Cambodian sapphire miner searching gems in a stream near Pailin.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

On Jan 02nd, 2010 we visited Pailin gem market near the Phnum Yat pagoda were we met again all the usual traders and miners. Very few stones were visible at the market as the dealers said that there was very few mining during the past days.

(A small parcel of rough blue sapphires seen at the Pailin gem market on January 02nd, 2010
Photo: V. Pardieu / GIA Laboratory Bangkok, 2010)

Around noon, after a short lunch at Samaki market, we returned to Chanthaburi where we could see that the traditional weekend gem market was very slow. Nevertheless we could see many rubies reportedly from Mozambique including numerous large "paw mai" (lead glass treated) and several parcels of small-unheated attractive faceted stones. We returned then to Bangkok in the afternoon.


It was a short visit but it was interesting to visit again Pailin and Chanthaburi after several months away in East Africa and it was a great occasion to meet and spend some time with Tracy and Neil.

May 13th, 2009 | Keywords:Field Report GIA , Pailin , Cambodia , ruby , sapphire Travel |
Blog Title: GIA Field Report 01 Online!: Pailin, Cambodia

GIA "Field Report": May 13, 2009: Concise Field Report Volume 01: Pailin, Cambodia (Dec. 2008 - Feb 2009):
Today we have created a new page on GIA Laboratory Bangkok Lab Research pages: In this page will be posted in the future the different public versions of GIA Field Gemologists' field trip reports. The first report to be put online is about Pailin in Cambodia: This report forms part of a series of simple yet informative reports that describe field trips undertaken by GIA Field Gemologists in order to obtain specimens from mines producing a variety of gemstones throughout the world. You can download the field report on the GIA Laboratory Bangkok "Field Reports " (follow the link) where you will find also many other interesting gemological studies from my friends and colleagues at GIA Laboratory Bangkok.

"Pailin ruby and sapphire"
Two rough ruby and blue sapphire seen on a typical brass plate used by most Pailin's gems dealers at the gem market. The stones present the typical tumbled aspect of stones mined from secondary deposits.
Photo: V. Pardieu / GIA Laboraotory Bangkok, 2009

After these two expeditions we have been able to get a good update about the present mining activity around Pailin and were also able to collect some very interesting samples for our Origin Specific Reference Collection. These stones will be very useful for our research about rubies and sapphires from South East Asia.
I will keep you informed but if you want to help, please contact me at the GIA Lab Bangkok indicating of course my name.
All the best,

March 2nd, 2009 | Keywords:Field Report GIA , ruby , sapphire , Pailin , Cambodia , Chanthaburi , Khao Ploy Waen Travel |
Blog Title: GIA FE04: Thailand, Cambodia: Back to Pailin!

GIA FE04 (GIA Laboratory Bangkok Field Expedition 04): Feb. 27- Mar. 01, 2009: Back to Pailin!
A second week end visit to Pailin in order to complete the visit we had few weeks ago: This time our objectives for this new week end expedition were to visit again the Khao Ploy Waen sapphire mines near Chanthaburi, the gem mines near Pailin and last but not least to visit the Phnum Trop volcano located in the mountainous jungle south of Pailin: With a group of friends we visited already this volcano in 2004. Five years after that visit it was interesting to get an update. During the past week Votha did the necessary with the Pailin authorities to get an approval for our visit.
For that expedition I travelled with a large group of friends: Richard W. Hughes and Wimon Manoratkul (Thailand), Loretta Castorro (USA), Walter Balmer (Switzerland), Flavie Isatelle, Philippe Ressigeac, Olivier Segura (France) and Randy Price (Canada).
In fact the visit was much easier as expected: The Russian Company who got the mining license few years ago did some good job repairing the dirt road to the top of the volcano and the Pailin local authorities provided us a good pick-up and an escort. We reached the mines after just one small mechanical problem, few short walks and several not so rough drives.

(The pick up loaded with 9 gemologists, a guide, an escort officer and a driver is ready to go!,
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009)

Sadly we could not witness any mining activity on the Phnum Trop as the Russian company was only doing some exploration work and the Russian miners were not present at the time of our visit. Only two guards were present. We return then to Pailin in the afternoon earlier than expected but it was not a bad thing as we were able to visit again the ruby mines we visited during FE01. It was again a good occasion to collect some useful ruby samples just out of the jig!

(A Khmer miner presenting us the result of one day working near O Beng: mostly garnets and few rubies.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009)

On Sunday morning we could visit the Pailin gem market which was less busy compared to last December. Nevertheless we could see some interesting parcels which pleased the young gemologists traveling with me that day. On the way back we could also witness some sapphire in a stream and again some ruby mining near O Beng.

(Down Phnum Yat Temple, Randy Price is checking some stones at the Pailin gem market.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009)

Again a very good week end expedition even if we could not witness any mining on the Phnum Trop as I was able to collect some interesting Pailin ruby and sapphire samples for the GIA's reference collection.

Here is a link to a beautiful photo gallery by Richard W.Hughes and Wimon Manoratkul which was put online on after our expedition to Pailin:
"Rhapsody in blue: A Pailin photo gallery"

Hoping that you will enjoy it as much as I did!

Here is a link to "Gems and Geology": Flavie Isatelle new website. She was.. lets say "convinced" by Richard and myself that the best thing for her to do was to build her own website and start writting about her gem and geologyl expeditions. You will find there her report about her Pailin experiences.

All the best,

December 21th, 2008 | Keywords:Field Report GIA , Chanthaburi , Thailand , Pailin , Cambodia , ruby , sapphire Travel |
Blog Title: GIA FE01: Thailand, Cambodia: Scouting for rubies and sapphires around Chanthaburi and Pailin

GIA FE01 (GIA Laboratory Bangkok Field Expedition 01): Dec. 18- Dec. 20, 2008: Chanthaburi and Pailin!
For my first "week-end" type Field Expedition since my arrival at GIA Laboratory Bangkok, a visit to Chanthaburi (Thailand) and to Pailin (Cambodia) was making a lot of sense: From 2001 to 2007 I visited regularly Chanthaburi and Pailin which are very interesting areas to visit in my opinion for any gemologist visiting Thailand.
It was a good occasion to start doing some good field work close to the lab, to get a first hand update about the ruby and sapphire mining there and to visit again old friends.
For that expedition Stephane Jacquat a gemologist from Geneva (Switzerland) joined me. It was a real pleasure to travel with him:

(At the morning gem market in Pailin, gemologist Stephane Jacquat enjoy breakfast and looking at sapphires.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2008)

We visited a mechanized sapphire mine just down Khao Ploy Waen temple just few kilometers away from Chanthaburi. This mine and the others in the area are known to produce black star sapphires, blue sapphires and yellow sapphires locally known as "Butsarakam".

(A mechanized sapphire mining operation near Khao Ploy Waen,
Photo: V. Pardieu / GIA Laboratory Bangkok, 2008)

After this visit we travelled to Pailin in Cambodia. During 2 days with the help of my friend Votha we were able to visit the local gem market and to witness sapphire mining inside Pailin and ruby mining in O Beng area and to after witnessing the mining we could collect some interesting samples directly out of the jig for the GIA reference collection.

(Here is one of the most interesting piece we saw that day: A milky blue sapphire crystal presenting a trapiche structure.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2008)

This first Field Expedition for GIA was a very successful one! It was also very nice to see again the Pailin gem miners and dealers.

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.