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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Fieldgemology Page on facebook

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:

Find our photos using the following Keywords:

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,


An update on Ruby and Sapphire mining
in South East Asia and East Africa.
Summer 2005

By Vincent Pardieu
and Jean Baptiste Senoble

General Presentation:(visit here)

Part 1) Introduction:(visit here)

Part 2) Vietnam (visit here)

Part 3) Sri lanka: (visit here)

Part 4) Madagascar: (visit here)

Part 5) Kenya:

I would like to first thank ICA Ambassador Suzie Kennedy and her husband Kennedy Kamwathi for their decisive help regarding this expedition, both for the preparation and for its execution. I've to say that I never had that much help from anybody on a field trip. It was wonderful to have Kennedy with us all along this trip. Thanks to him, we were able to learn so much. Thanks to Kennedy and Suzie, we were able to go to the mines we wanted to visit and we were able to have some very nice talks with Kenyan miners and dealers. I want to add that throughout trip, we have been really fantastically welcomed in all the mining operations we visited.

Our schedule was the following: We arrived in Kenya on July 8 th , 2005 from Madagascar where we had spent a little bit more than one month visiting also ruby and sapphire mines. We left this country on July 27 th, 2005 to Tanzania in order to continue our study of rubies, sapphire, and tsavorite.

The main focus for this trip was on ruby, but we could not visit Kenya without getting interested by Tsavorite.

We first visited the ruby and tsavorite mining areas in the Tsavo region, which is currently the main Kenyan gem mining area. We used Voi as an operational base for our visits in the Tsavo area. It is interesting to notice that this city, which is also a touristic gate to Tsavo national park, was said to have been mainly built with “Tsavorite money”.

First we focused in Kasigau and Mangare areas located in the border of the Tsavo West National Park. There, several companies are involved mainly in ruby mining but some of them have also started some smaller scale tsavorite and chrome tourmaline mining. These operations are mostly mining primary deposits located in metamorphic rocks. Most of the companies there are already well established as they started in the 1970's after Campbell Bridges' and John Saul's discoveries near Taita-Taveta districts. We visited the following companies which are located very close by:
- “EQUADOR”, involved mainly in ruby but which is also beginning to mine some Tsavorite deposits very close to its main ruby operation.
- “HARD ROCK”, which is a neighbor to Equador, is mining rubies.
- “AQUA” is mining both rubies and tsavorite and in planning to build a camp to welcome people interested in gems who are willing to visit the area.

(Left to Right: Visiting the Equador mine, J.B. Senoble and K. Khamwathi at Hard rock ruby Mine.
Photos: Jean Baptiste Senoble and Vincent Pardieu, 2005)

(Left to Right: Going down to visit “Aqua” mine, A fine ruby crystal from “ Rockland ” mine,
Photos: Jean Baptiste Senoble and Vincent Pardieu, 2005)

We also went to visit the famous “ROCKLAND”, also known as “John Saul's mine”, which is the most well known mine in the Mangare area and finally the new “MEGALITH” project which is, by the size of its mining concession, the largest operation in the area. But this last operation is the most recent one and has not currently produced as much as the other older mines.
The rubies we were able to see during these visits were to the best fine cabochon grade, some of the stones also look to have some heat treatment potential. It had been reported that some gem quality stones have been found, but we were not able to see such quality. This gem quality material was reported to us to have been mined, most of the time, in the elluvial deposits that were mined on the surface when the operations started. It was not very surprising as only the most durable stones can survive to the natural weathering. The mining operations there started the same way: First some elluvial deposits were located and mined then a gem bearing rift was found and hard rock mining operations started. Currently some mining shafts or trenches are more than thirty meters deep. It was also interesting for us to see that within such a small area the stone color, quality, and types were very different from mine to mine. This was also true within the same mining operation depending of the rock in which they were located.
After visiting the Kasigau and Mengare areas, we went to visit mainly tsavorite mining operations in the Kuranze area a few kilometers from the Tanzanian border southeast of the Kasigau area. We also visited the Mwatate area in the Taita Hills on the other side of the Tsavo West National Park.
In the Kuranze area, we visited “BOCREST GEM ENTREPRISES LTD”, “TSAVOLITE MINING LTD”, “MBERILLI” and “NADAN” while in Mwatate area we visited “BARAKA”, “BRIDGES EXPLORATION” and finally “DAVIS”.

(Left to Right: Tsavorite rough from Kuranze area, Kenya; J. B. Senoble and Kennedy Khamwathi checking daily mining production with Campbell Bridges at his mine in Taita hills, Kenya .
Photos: Vincent Pardieu, 2005)

(Left to Right: Kennedy with a happy miner and a large tsavorite; Leaving a Tsavorite mine in Kuranze area.
Photos: Vincent Pardieu and Jean Baptiste Senoble, 2005)

The tsavorite mining operations we visited were globally smaller scale compared with the ruby mines but were also mining the same way: The first step is to localize some elluvial deposit on the surface and then to find the primary deposit and to mine it. Mining tsavorite requires some serious practical geologic and mining knowledge in order to optimize the localization of the porphyroblasts or the boudins which are respectively locally called “potatoes” and “eyes” and are the tsavorite rich. But few of the miners we visited had that serious technical mining or geological knowledge. Anyway it seems that regarding to tsavorite mining, even in the most technically advanced mines, “being lucky” is the thing that makes the difference. We were able to see lots of very nice tsavorite rough in colors from deep bluish green to green and to yellowish green. If the colors were very attractive, most of the stones were small in size.

As a result of these visits to tsavorite mines in Tsavo district, some data were collected so AIGS Gemological Laboratory will be able to soon produce an article on tsavorite for the AFG, the “Association Francaise de Gemmologie” (the French Gemological Association). To complete this work, we planned to visit some tsavorite mining operations in Tanzania in the next few days.

It was interesting to notice that none of these areas had any visible security or illegal mining problems except for the “ DAVIS ” mine in Taita hills which has some serious troubles with illegal miners, locally called “Zaruras”. All the mining areas were quiet and the only “disturbance” was the common encounter with wild elephants, antelopes, and zebras which are common around the mining operations. This is a good point for the miners which, in both Kuranze and Mangare/Kasigau areas, are searching for investors in order to help them to develop their operations, mechanize their mines and market their production.

After our visits to the Tsavo area, we came back to Nairobi and went to visit a very promising ruby and pink sapphire mining operation in the Baringo district which is getting ready to seriously start its mining operations after a long preparation time. The stones produced in this area present some different qualities but most of the stones are going from pink to red, with the pink and purplish dominating the deposit. The stones are found in alluvial deposits from basaltic origin.

(Left to right: Visiting “ Corby ” mine in Baringo area, ICA Ambassador to Kenya Suzie Kennedy presenting Baringo rubies, Nitin. N Pattni director of Corby Ltd at his mine in Baringo.
Photos: Jean Baptiste Senoble, 2005)

Now besides these two areas which are currently in production or on the edge to start production, several other corundum deposits are known in Kenya as in Garba Tula (blue and green sapphire), Turkana (sapphire) and in other areas all over the country which, due to its location along the Mozambique belt, present some very high potential for future major gemstone discoveries. All these areas are currently producing small amounts of gems and/or are presenting some serious security problems, especially along the Ethiopian and Somali borders, so we decided not to go to visit them.

Nevertheless, the very good news is that we were able to visit a new promising ruby deposit producing stones much more saturated in color compared to the gems found in the Baringo district. The samples we could find in this volcanic area look very similar to the rubies mined in the Thailand/Cambodia deposit. With the pink rubies from the Baringo area, these new rubies present some serious hope for the Kenyan gem industry as the stones we saw were of commercial to very fine facet quality. Now as this new deposit was just found few weeks before our arrival in Kenya, and regarding the fact that we saw only around twenty samples from this location, it is still difficult to say if this new ruby deposit presents a major economical potential and is suitable for large or small scale mining. Anyway, the quality of the rubies we saw there was globally the best that we saw on our entire Kenyan trip. Besides that, I'm currently not able to disclose the location of this new find as an agreement with the owner of the mining rights who invited me to visit this promising area. Nevertheless, we have collected some samples in order to study them.

I would finally like to advise people and companies interested by the present report to contact ICA ambassador in Kenya, Suzie Kennedy, to get more details about the local situation and to conveniently contact the correct persons.

Part 6) Tanzania(August 2005)(visit here)

Visit also our 2006 fieldtrip reports

Introduction: Presentation of the AIGS, Gubelin Gem Lab, ICA 2006 fieldtrip to central Asia: (visit here)

Part 1: Pakistan: The Central Asian capital of the gemstone trade. (visit here)

Part 2: Afghanistan: Land of beautiful gems and unique people. (visit here)

Part 3: Tajikistan: Gems from the Pamirs. (visit here)

Part 4: China (Xin Jiang): Emeralds from the silk road. (visit here)


Note: For more information and photos about all these different areas, please visit our photo galleries available from our home page.

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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.