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)


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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)

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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,

October 12th, 2010 | Keywords:tsavorite , Lemshuku , Tanzania , Kenya , garnet Travel |
Blog Title: Article about Lemshuku tsavorite deposit, Tanzania

Dear all,
I would like to inform you of a new publication about tsavorite. It is about the geology of the Lemshuku deposit in Tanzania where these green garnets were discovered there in 1967.

"Lithostratigraphic and structural controls of ‘tsavorite’ deposits at Lemshuku, Merelani area, Tanzania",

an article by Julien Feneyrol (a), Gaston Giuliani (b), Daniel Ohnenstetter (b), Elisabeth Le Goff (c), Elias P.J. Malisa (d), Mark Saul (e), Eric Saul (e), John Saul (f) and Vincent Pardieu (g)

- (a) CRPG-CNRS, Nancy université, 15, rue Notre-Dame-des-Pauvres, 54501 Vandœuvre-lès-Nancy, France
- (b) IRD-LMTG, 24, avenue Édouard-Belin, 31200 Toulouse, France
- (c) BRGM, 3, avenue Claude-Guillemin, 45060 Orléans, France
- (d) Department of Geology, University of Dar-es-Salaam, P.O. Box 35052, Dar-es-Salaam, Tanzania
- (e) Swala Gem Traders, Uchumi House, Sokoine Road, Arusha, Tanzania
- (f ) ORYX, 3, rue Bourdaloue, 75009 Paris, France
- (g) GIA Laboratory Bangkok, 10th Floor, U-Chu-Liang Building, 968, Rama IV Road, Silom Bangrak, Bangkok, Thailand


The first study of the Lemshuku ‘tsavorite’ mining district is presented. From bottom to top, the lithostratigraphic column corresponds to a metasedimentary sequence composed of quartzite, fine-grained graphitic gneiss, kyanite-graphite gneiss, biotite-almandine gneiss, metasomatized graphitic gneiss and dolomitic marble. ‘Tsavorite’ occurs in quartz veins and rarely as nodular concretions. Two factors control mineralization: (1) lithostratigraphy, with ‘tsavorite’ in association with pyrite and graphite confined to quartz veins within the metasomatized graphitic gneiss; and (2) structure, with the mineralized veins characteristically controlled by tight isoclinal folds associated with shearing.

It was published in Comptes Rendus Geoscience, Volume 342, Issue 10, October 2010, Pages 778-785.

It is also currently available online


(Mark Saul of Swala Gem Traders presenting the author a piece of tsavorite he just mined at Lemshuku
Photo: V. Pardieu / Gubelin Gem Lab, 2007)

The author visited the Lemshuku deposit in 2005 and 2007 when Swala Gem Traders mined it. In 2009, few months after Julien Feneyrol to spend several weeks at Lemshuku to study the deposit, Swala Gem Traders stopped their mining operation there. While returning to East Africa in October 2009, the author was not able to get in contact with the new owner and thus could not visit it once again. If what is currently happening at the former mine operated in the past by Swala Gem Traders is not clear to the author, the area is nevertheless still very interesting as Tanzanite One with their "Tsavorite One" project have started also to prospect in the region around Lemshuku. The author would then not be surprised to read or hear again about Lemshuku in the future as one of the main tsavorite supplier in East Africa.

Note: Update about the July 2010 tsavorite workshop in Nairobi, Kenya:

Today I was able to communicate with Dr. Gaston Giuliani from the Nancy University on another subject related to Tsavorite: Last year in October 2009, we tried to visit together the ruby and tsavorite deposits in Kenya but our expedition was not really succesful (see blog Kenya 2009).
Dr. Giuliani and Dr. Ohnenstetter were then just back from a tsavorite workshop in Dar Es Salaam (Tanzania) and they were working on a similar project for 2010, this time in Nairobi (Kenya). Today I was told by Dr. Giuliani some excellent news about the Nairobi 2010 workshop he was then planning:
The workshop happened and reportedly turned to be very successful. After the workshop more than 40 people also were able to go on a field expedition to Tsavo lead by Dr. Cedric Simonet.
Currently a research program about tsavorite in collaboration between Kenyan and French Universities is in preparation. Dr. Giuliani told the author that he was very happy about the way things happened during summer 2010.

For more information about tsavorite, the author also invite you to read "Tsavorite, an Untammed Gem" an article written with R.W.Hughes, first published in ICA's InColor (Winter 2008)

All the best,

October 17th, 2009 | Keywords:IGC , Merelani , Longido , Manyara , Tanzania , congress Travel |
Blog Title: GIA FE09 Oct. 08 - Oct. 15, 2009: 31st IGC Congress Arusha

GIA FE09 (GIA Laboratory Bangkok Field Expedition 09): Part 05: Oct. 08 - Oct. 15, 2009: 31st IGC Congress Arusha:

After spending many hours driving on dusty roads or visiting mines, these few days in Arusha were the occasion to meet a lot of people, attend to interesting presentations and also travel around Arusha to visit mining area with the rest of the gemologist attending the IGC.


But first you may wonder what exactly the IGC is?


The I.G.C. stands for the "International Gemological Conference". It was started in Europe in 1952 by a group of enthusiastic gemologists, including the famed Prof. Edward Gubelin. It is a bi-annual gathering which is attended by gemologists from around 30 different countries. The main goal of this organization is to enable cooperation between gemologists from around the world particularly between gemologists from gem producing countries and gem consuming countries. Membership is by invitation only, and has some specific rules: Typically each country can have only a maximum of 2 to 5 representatives (depending on country size) selected on the basis of scientific and ethical standards. This organization is independent from any commercial operation. Besides the normal members, the organizer can also invite some guests to attend to the conference. Usually the IGC is then some kind of "old timers" meeting but this time, and this is something very new, several young gemologists were among the people invited to the conference.

I was invited at the 31st IGC as a guest by John Saul and his son Mark Saul (Swala gem Traders), as they knew that I was traveling to East Africa for the GIA Laboratory Bangkok at the time of the IGC. It was my first participation to such event and it was a real pleasure. The event despite the economic crisis was successful: It was well attended with about 40 people from about 15 countries including many friends.

The conference was open on Oct 9th in the evening after a speech from the Governor of the Arusha region. The opening ceremony was followed on Oct 10th and 11th of 2 days with interesting gemological presentations at the Arusha hotel. There was an obvious focus on gemstone deposits and gems from East Africa, but these were also several interesting presentations about pearls, diamonds and some general gemological topics. As a guest of John Saul I was not supposed to give a presentation, nevertheless Thanong Leelawathanasuk from the GIT who was giving a presentation on Mozambique rubies was very nice to invite me at the end of his presentation to give an update about the different ruby mining areas in Mozambique.


The conference was the occasion for the IGC board to be renewed. It is composed now of the following seven members (by alphabetical order): Georges Bosshart (Switzerland), Emmanuel Fritsch (France), Henry Hanni (Switzerland), Michael Krzemnicki (Switzerland), Jayshree Panjikar (India), John Saul (International), Tay Thye Sun (Singapore), Gamini Zoysa (Sri Lanka) and Hanco Zwaan (Netherlands)


At the end of the conference, as usual the people attending the conference were asked about the location of the next IGC, the only proposal was from Michael Krzemnicki who proposed to host the 32nd IGC in Switzerland in 2011.


It was also proposed to create a website for the IGC which in my opinion would be a good thing as it was not easy to get reliable information about what is the IGC on the Internet.

But the IGC was not just about nice gemological presentations and coctails parties in a cosy hotel: At the end of the congress we had 3 days with short field trips to gemstones mines around Arusha...

The lab rats were going to explore rat holes!

It was a pleasure to get a chance to go to the field with some gemological monuments. A real pleasure, fun and interesting!


- On Monday 12th, 2009 we went to visit the Tanzanite One mining operation in Merelani. For the occasion Tanzanite One gave us the possibility to visit the Tanzanite Museum which will be open to the public within few weeks. With the rest of the group I went underground and visited the shaft Tanzanite One arranged for the public: The JW shaft. That was interesting as in 2005 I visited the "Main Shaft" and during my last visit in sept. I visited the "Investor shaft".

For more info on Tanzanite: Please follow the link to our Tanzanite article.


"Tired but happy: Tay Thye Sun (Singapore) and Jashree Panjikar (India) are returning from an underground visit

at the JW shaft: Tanzanite One oldest pit in Merelani"
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

- On Tuesday 13th, 2009 we went to visit the oldest gemstone mining area in East Africa: The Mundarara ruby mine at Longido producing mainly carving quality ruby in zoizite material for nearly 50 years. I visited already the mine in 2005 with Jean Baptiste Senoble. It was a pleasure to travel to the mine driving through the Massai in the North of Mount Kilimanjaro: On the way we saw several giraffes, oastriches, zebras, gazelles and antelopes. This new visit at Longido was interesting as unlike in 2005 we were able to go underground, witness how ruby on zoizite was mined and collect underground some interesting reference samples.


"The IGC group going down in Longido ruby mine"
Dr. Benjamin Rondeau from Nantes University (France) is getting ready to go 300 meters underground in what

is probably East Africa's oldest mining pit.
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

- On Wednesday 14th, 2009 we went to visit the Manyara emerald and alexandrite mines located near the famous Manyara National Park. It was interesting to see the difference few years after my visit in 2007. To reach the mine we entered the Manyara National Park by the north and drove for about one hour through the Park bordering Lake Manyara which was very dry. On the way we could see many wild animals: Elephants, buffaloes, antilopes, giraffes, baboons, and many birds. It is all the time a pleasure for me to see Nature associated gemstones. The fact is that national parks are truly gems as they also fit to the definition of a gem as they associate beauty, (sadly) rarity and (I hope...) durability.


"Exploring emerald and alexandrite mines in Manyara "
Visiting the alexandrite and emerald mining area near Manyara I could not resist to explore the old mine tunnels.
Prof. E. Fritsch from Nantes University (France) was following me underground. I was impressed!
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

- After that most of the people attending the conference went to visit the Williamson diamond mine while some others went to visit the Mahenge spinel mining area or the Winza ruby and sapphire mines. On my side I left for the week end with an old buddy: Swiss gemologist and geologist Walter Balmer who was also attending the conference. Walter gave a very interesting presentation about the geology of the ruby rich Uluguru Mountains near Morogoro. He was also traveling in East Africa for about a month around Mahenge and Morogoro. We decided that it was time to take two days resting. We then went to fulfill an old dream and went camping on the Ngorongoro caldera. That was gemmy!

"Camping on the Ngorongoro caldera "
Camping in the wild in East Africa is all the time an interesting experience, in the evening an elephant was quietly feeding while around the camping site, while during the night a pack of zebra visited us doing weird noise. In the morning it was nice to meet 20 meters from the camp entrance a wandering hyena!
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

It was a very interesting visit as I was able to rest and think a bit about some projects I wanted to work on for many years.

On October 17th I then left to Nairobi in Kenya to try to visit the Tsavorite and ruby deposits in Tsavo area in Southern Kenya.


All the best,

October 9th, 2009 | Keywords:Tanzania , ruby , spinel , tsavorite , tourmaline , garnet , Mahenge , Morogoro , Umba , Winza Travel |
Blog Title: GIA FE09, Part 3: Tanzania Sept. 2009

GIA FE09 (GIA Laboratory Bangkok Field Expedition 09): Part 04: Sep. 20 - Oct. 07, 2009: Central Tanzania:

This is the third part of the GIA Field Expedition to East Africa, I'm leading for the GIA Laboratory Bangkok: I arrived in Dar Es Salaam, Tanzania from Mozambique with gemologists Lou Pierre Bryl (Canada), and Flavie Isatelle (France) on Sep. 20th 2009. We met there our Tanzanian friends: Abdul Y. Msellem a Tanzanian gem broker and Moussa a Tanzanian driver working for Fortes Safaris.

Our objective was to continue the work I did during my previous expeditions in 2005, 2007 and 2008. This time our focus was to visit the ruby and spinel deposits in Central Tanzania at Winza, in the Morogoro province (in Matombo and Mahenge districts) and around Umba.

Our visit started in the Tanzanian capital Dodoma to get the support of the mining officer to visit Winza. We did not miss the opportunity to visit the Geological Survey of Tanzania in order to get some useful maps and publications.



"Our team (left to right: Vincent Pardieu, Flavie Isatelle and Lou Pierre Bryl) leaving the Geological Survey of Tanzania in Dodoma: It is all the time useful to get some good maps and publication before to visit gem mining areas"
Photo: A. Y. Msellem / GIA Laboratory Bangkok, 2009

We then left to visit Mpwapwa and the Winza ruby and sapphire mines. I visited already Winza with Jean Baptiste Senoble in April 2008 and we were then the first gemologists to visit this unique deposit.

(For more information about Winza, please visit our Winza expedition report and for more information about the gemology of these interesting rubies and sapphires, please read the complete article published in Gems and Gemology about Winza)

It was then the end of the rainy season and more than 5000 miners were working there washing the gem rich ground for rubies and sapphires and digging the hard rock underneath to get blue and pink sapphires.

During that new visit we found that around 500 miners were still working there. We could visit the mining area and collect some interesting samples. An update about ruby and sapphire mining in Winza will be soon published by the GIA Laboratory Bangkok after my return in Thailand. I will keep you informed.

"Geologist and gemologist Flavie Isatelle returning to the surface after a visit underground in Winza"
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009


After our visit to Winza we focused on visiting the ruby and spinel deposits in the Morogoro region. First we visited the ruby deposits located in the Matombo district of the Uluguru Mountains in the west of Morogoro. We visited the different mining area near the Mwaraze and Ngongolo villages, I visited already in 2005 (see our Tanzania 2005 expedition report), and which were very active during the 1980's up to the beginning of the 1990's producing rubies.

After this visit we continued to the Mahenge where we visited the spinels deposits near Ipanko, Mbarabanga and Kituti. It was interesting to see the evolution of gem mining at Ipanko after our visits in 2005 and 2007. Spinel mining stopped at Ipanko few days after our visit in 2007 and started again in April 2009 after a controversy regarding the mining rights. Ipanko is now again producing beautiful red spinels and is now the most active gem mining area in Tanzania after Merelani with nearly 1,000 miners.

Besides Ipanko we also spent some time continuing the visits I did in 2005 and 2007 of the numerous ruby deposits near Lukande, Mayote, Chipa, Gombe, Ibogoma, Nbangayao, Kitonga, Kitwaro and Kisewe. Some of these areas were reported to have produce during the 1980's and 90's some very fine and large marble type rubies and they remain very poorly known.

"Mahenge Spinel Crystal"

This rough crystal we saw at the mines was weighting nearly 100 grams, this is nothing compared to a 54kg rough spinel but this can give an idea about what we speak about...
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

After that visit we drove to the north of the country to Tanga and the Umba valley. Tanga is a special place for me as in 2005 I spent there some of the hardest days of my life when I was suffering from malaria.

This time our visit was more pleasant: We visited first the red zircon deposit at Mwakijembe then we visited sapphire, ruby, tsavorite, rhodolite, almandine and malaya garnet mines along the Umba river near Kigwasi and Kalalani. Then on our way back we turn our interest to tourmaline mines at Ngombeni and in the Usambara Mountains.

"A Massai trader present us his treasure: A pair of blue and orange Umba sapphires"
Photo: V. Pardieu / GIA Laboratory Bangkok, 2009

After that visit we returned to Arusha in order to do the export process for our reference samples collected in the field on site while visiting mines.

It is also for me the time to spend some more cozy times participating to the 31st IGC (International Gemological Conference) which will start on Oct 9th and will finish on Oct 14th.

"The 31th International Gemological Conference, Arusha, Tanzania, 2009"

The IGC conference means also that it will be time for my traveling companions: Lou Pierre Bryl and Flavie Isatelle to continue their own travelings respectively to Poland and Madagascar.

It was very nice to have them with me during that expedition as they were very helpful motivated to visit Tanzanian gem mining areas. I wish them all the best.

On my side after the end of the conference I will continue to Kenya with new travel companions: Dr. Gaston Giuliani and Dr. Daniel Ohnenstetter from Nancy University, France and Dr. Stephanos Karempelas from the Gubelin Gem Lab in Lucerne, Switzerland.

Our focus will be on visiting ruby and tsavorite deposits around Voi in Southern Kenya.


All the best,

October 7th, 2009 | Keywords:Tanzania , Meralani , tanzanite , tsavorite , Travel |
Blog Title: Minerological Record article about Merelani

New Publication: Merelani, Tanzania published by "the Mineralogical Record", Sept-Oct 2009 Vol. 40 Number 5:

I would like to invite you to read the new publication I collaborate with about the Merelani mining area in Northern Tanzania: This article was recently published by "The Mineralogical Record" It was written in collaboration with Wendell E. Wilson, John M. Saul and Richard W. Hughes.

The origin of the article was the report of the 2007 expedition I had with Richard W. Hughes, Guillaume Soubiraa, Mike Rogers, Monty and Warne Chitty and Philippe Brunot.

Thanks to the contributions of Richard W. Hughes, John M. Saul and Wendell E. Wilson this expedition report turned into a terrific 63 page article beautifully illustrated with many photos of some of the finest Tanzanite, tsavorite, Axinite and diaspore crystals ever mined in Merelani.



"Merelani, Tanzania "
The Mineralogical Record, September-October 2009

It was a pleasure to collaborate to this article and even more to read it. I hope that you will enjoy it as much a I did.

All the best,




September 5th, 2009 | Keywords:Tanzania , tsavorite , tanzanite Travel |
Blog Title: FE09, Part 01: Arriving in North Tanzania

GIA FE09 (GIA Laboratory Bangkok Field Expedition 09): Part 01: Aug. 29 - Sep. 02, 2009: Tanzania:

This is the first part of the GIA Field Expedition to East Africa, I'm leading for the GIA Laboratory Bangkok: I arrived in Arusha, Tanzania from Bangkok with Canadian gemologist Lou Pierre Bryl on Aug. 28th 2009 in the morning. We were joined there in the evening by Swiss gemologist Stephane Jacquat.

Our first task was to prepare the things for the coming expedition to Mozambique and Tanzania scheduled for Sept 2009. We met our usual local Tanzanian contacts: Mark Saul from "Swala Gem Traders", Abdul Y. Msellem, a Tanzanian broker I had already as guide in 2005, 2007 and 2008 and Moussa our driver (from Fortes Safaris). Thanks to their support after a short visit to the Arusha mining officer and few phone calls to different miners, we got rapidly everything ready regarding our vehicle, our schedule, the necessary paperwork to enter the mining areas.

Few hours after our arrival we could start our visit with the Arusha market and the "Tanzanite Experience", a very interesting museum dedicated to Tanzanite located just opposite of the Tanzanite One office in Arusha. There we could have a very interesting visit. That museum really worth the visit as at the end we had the pleasure to be able to see and manipulate a very fine and large Tanzanite crystal which is used for demonstration:

"Tanzanian beauties"
Teddy Kallaghe, a sales staff at the "Tanzanite Experience" in Arusha is presenting us a fine tanzanite crystal reportedly unheated.
Photo: V. Pardieu/GIA Laboratory Bangkok, 2009

The next day on Aug 29th, with the help of Tsavorite miner Rafael Manyosa, we traveled to the new tsavorite deposit at Namalulu, a small village located south of the Lemeshuko and Lendanai areas. The areas was reported to have been discovered in Aug 2008 by Massai "moranis" (young Massai "cow boys"). Rapidly two Massais: Mr. Urubundu and Mr. Saruni started to mine the area. Within few months in Dec. 2008 about 500 people were mining and trading tsavorite at Namalulu. Then as it was necessary to go underground to do hard rock type mining, we were reported that many miners left to go to mine at the Lemeshuko area after the departure of the Saul Brothers when they closed their mine at the end of 2008. At the time of our visit about 150 people were mining in Namalulu. There was 3 important and deep underground mining operations and several smaller ones. After meeting the local miners and explaining the purpose of our visit we were able to visit 3 mining pits: First the Yoshua Kivuyo (Massai miner) pit which was about 30 meters deep, then the exploitation from Rafael Manyosa (our guide) and his Massai partner: Mr. Kikanai. There we were lucky to witness the discovery of a fine tsavorite pocket. Finally we visited the mine of Mr. Saruni, a very deep mine (about 150 meters) which is also one of the oldest as Mr. Saruni was the second miner to start working at Namalulu.

"Rough green gems from the Massai steppe"
A Massai miner is presenting us a parcel of rough tsavorite he found mining underground in Namalulu.
Photo: V. Pardieu/GIA Laboratory Bangkok, 2009


For the following 2 days we decided to focus on Merelani, where Tanzanite is mined:

On Aug. 30 we travelled to Merelani to visit the "Bedui Camp" mine located in the Karo area (Merelani bloc D"). The Karo area is famous to have produced not only Tanzanite but also some very large tsavorite. Using wooden ladders and ropes we went down to the deep of the mine where we could study the local geology. The visit was easy as it was Sunday and the miners were on week end: As nobody was working there at the time of our visit the mine was not too dusty and it was more easy then to breath and study the rocks 300 meters underground.

"Hope is the Merelani miner mistress... Hard work his daily life."
"Rasta man" is mining underground in Merelani for nearly 20 years,
He was our guide, 300 meters underground visiting the "Bedui Camp" mine in Karo area, Bloc D", Merelani.
Photo: V. Pardieu/GIA Laboratory Bangkok, 2009

On Aug 31, we visited the "Tanzanite One" operation located in Bloc C at Merelani. The visit was again very interesting starting with some good explanations about the local geology with geologist Vitus Ndakize then a visit of the "Investor pit" with Mining Engineer and Manager Damien Massala and finally Mervyn Dettmer took us to visit the processing plant and the sorthouse.

A truly very interesting visit, particularly after visiting a mine in Karo area.


On Sept 01 we took the bus to Dar Es Salaam in order to fly the next day to Nampula in Mozambique to start the second part of this GIA FE09 expedition to East Africa with a visit of the famous tourmaline deposit in Mavuco (near Alto Ligonha) and the two new ruby deposits in Niassa and Cabo Delgado provinces.

All the best,

October 26th, 2008 | Keywords:tsavorite , Bridges , Kenya , Tanzania , Madagascar , Tsavo , Merelani , Umba , Gogogogo , Ruangwa , garnet Travel |
Blog Title: Tsavorite untamed beauty

Tsavorite: An Untamed Beauty:


This article written by the author in association with Richard W. Hughes was first published in InColor, Fall 2008, pp. 36–45, the magazine of the ICA (International Colored stone Association).It was a special request from the ICA as they had appreciated another article from the author about tsavorite called "Tsavorite, une pierre Africaine" published in the French gemological magazine: "Revue de gemmologie AFG" in 2005.

The article is also available online on and also on Richard W.Hughes website:




"Tsavorite cut, rough and porphyroblast from Tsavo region, Kenya"
Stones courtesy: Genson Micheni Musa/ Tsavolite Co Ltd, Photo: V. Pardieu/Gübelin Gem Lab, 2007


Traveling to East Africa in 2005 with Jean Baptiste Senoble, the author priorities were mainly rubies and sapphire, nevertheless Jean Baptiste Senoble had a contagious passion for green stones and motivated the author to add to their visit schedule the tsavorite deposits located in Tsavo near the ruby mines. Things became worse for the author when JB Senoble got the support of African mining veteran Campbell Bridges, then he got into a passion for the "Untamed green beauty".

There is nothing more contagious than traveling to the source with a gem afficionado. Few years after that first adventure, the author was each time he got a possibility, the author was enjoying visiting tsavorite deposits. With this article the authors are trying to explain their interest for this fascinating gem.

All the best,

August 31th, 2008 | Keywords:spinel , Burma , Mogok , Namya , Vietnam , Tajikistan , Tanzania , Travel |
Blog Title: Spinel, the resurection of a classic

Spinel, the resurection of a classic:

This article written by the author in association with Richard W. Hughes and Edward Boehm was first published in InColor, Summer 2008, pp. 10–18, the magazine of the ICA (International Colored stone Association).

With that article the author wanted to share his old interest and understanding of spinel, a stone that he discovered while studying gemology in Burma, living with a Burmese spinel dealer and then working for a short while as a spinel buyer for a great spinel connoisseur: Henry Ho.

The article is also available online on and also on Richard W.Hughes website:




"Gemologist Hai An Nguyen Bui studying a spinel crystal from Namya mining area, Northern Burma"
Photo: V. Pardieu, 2006

Hoping that you will like it.
All the best,

July 30th, 2008 | Keywords:Tanzanite , Tanzania Travel |
Blog Title: Working the blue Seam

Working the Blue Seam, the Tanzanite mines of Merelani:


This article was published in the Australian Gemmologist July September 2009, Vol. 23, Number 11. pp. 482–494.
For that article author Richard W. Hughes used as inspiration the expedition report by author Vincent Pardieu published on this website after the Oct. 2008 joint expedition they had in Tanzania.

The article is currently available online on and also on Richard W. Hughes website:



"Working the blue seam, the Tanzanite mines of Merelani"
Photo and artwork: Richard W. Hughes.


As usual it was a pleasure to work with Richard on such article. Thanks Richard to have taken the time to do the necessary to improve that report...

April 27th, 2008 | Keywords:Tanzania , Winza , ruby , sapphire Travel |
Blog Title: A visit to the new ruby and sapphire deposit in Winza, Tanzania

A visit to the new ruby deposit in Winza, Tanzania: (Apr. 15 to Apr. 22, 2008):

"In November 2007, rubies of high quality and pure red to pinkish-red colour were found near the village of Winza, (Mpwapwa district), in the Dodoma region of Tanzania, and quickly attracted attention outside Tanzania - most recently at the BaselWorld show (in April 2008). The superior quality of these rubies and sapphires is characterised by outstanding transparency..." ( text from the Gübelin Gem Lab Newsletter n22 published on May 05, 2008)

Obviously when such exceptional gems appear in the market for a gemologist specialized on origin determination of gemstones, a visit to the new mining area makes a lot of sense. I decided, with the support of the Gübelin Gem Lab, I was then working for, to visit this new deposit few days after the end of the BaselWorld show at the end of April 2008. Jean Baptiste Senoble, an enthusiastic young French gemologist and gem lover who used to travel with me in Tanzania in 2005 joined me on this expedition. The purpose of this expedition was to collect first hand data and samples in order to maintain the Gübelin Gem Lab gemstone reference collection up to date and to collect first hand data about gem mining and trading in Winza for future articles and presentations on these stones.

This specific April 2008 expedition was facilitated by the fact that in August 2005 and October 2007 , the author did two very complete surveys of the gemstone mining areas in Kenya and Tanzania (see following map) with Tanzanian gem broker Abdul Y.Msellem as guide and with the support of Eric Saul (ICA Ambassador to Tanzania) and his brother Mark from Swala Gem Traders in Arusha, which are licensed gem miners and dealers in Tanzania. These expeditions were very useful to collect, of course, additional samples and data from known gem sources but also to build and maintain a strong local network (with Tanzanian gems dealers, brokers, miners, mining officers and technicians) which turned to be very useful and reliable for the Winza case.

"Winza rubies"
A group of Winza ruby and sapphire crystal specimen collected by the author while visiting the Winza gem mining area in 2008 associated with two beautiful faceted rubies seen in Paris.
Stones courtesy: Gübelin Gem Lab / Van Cleef and Arpels / Piat / Swala Gem Traders, Photo: V. Pardieu, 2008

From April 15 to 22, 2008, with the support of our Tanzanian friends and from the Tanzanian local authorities we succeeded to reach the new mining area where we stayed 3 days at 2 nights in order to witness and document the mining activity. A complete report about our field expedition is currently available on this website:

Now a complete field trip report is available on this website at the following link:

The Winza ruby and Sapphire mining area,
Mpwapwa district, Dodoma province, Tanzania

"Winza landscape"
A view over the Winza ruby washing and mining area on the Mtindiri riverbanks and on the Mangalisa mountains.
Photo: V. Pardieu / Gübelin Gem Lab, 2008

About 2 weeks after the author and Jean Baptiste Senoble visit of the Winza mining area, in May 2008, GIA gemologists: James E. Shigley and Brendan M. Laurs also succeded to visit Winza in order to document the location, the geology, and the mining of the new ruby and sapphire deposit. They were accompanied by gem dealer Dimitri Mantheakis (Ruvu Gemstone Mining Ltd., Dar es Salaam ), who arranged the logistics and helped them to obtain the necessary permissions for that visit, and by several government officials for their security.

After these two expeditions, the Gübelin Gem Lab, the GIA and other researchers decided to collaborate to produce a common article about " Rubies and Sapphires from Winza, Central Tanzania " by Schwarz D, Saul J.M., Schmetzer K., Laurs B.M., Giuliani G., Klemm L., Malsy A.-K, Erel E., Hauzenberger C., Du Toit G., Fallick A.E., Ohnenstetter D. and Pardieu V. in Gems & Gemology, Vol. 44, No. 4, Winter 2008, pp. 322-347.

Besides the article, some addtional photos taken during the 2 expeditions by the Gübelin Gem Lab and GIA and some additional inclusion photos of Winza gems are also available on G&G Data Depository on GIA website.

"Abdul M'Sellem and a winza sapphire specimen"
A special thanks to our friend Abdul M'Sellem, an Arusha based Tanzanian gem broker, who was the first to inform the author about the new ruby deposit in Winza at the end of November 2007. Thanks to his support, we were able to have a very succesful expedition in April 2008 and to be the first gemologists to visit that area.
Photo: V. Pardieu / Gübelin Gem Lab, 2008

Visiting Winza and studying Winza rubies and sapphire was a great gemological adventure for me, it was probably one of the best things I will remember about my two years working as a gemologist specialized on Origin determination of gemstones at the Gübelin Gem Lab in Lucerne, Switzerland. We had the occasion then to do some great team work under the direction of Dietmar Schwarz in order to provide rapidly to the gemological community a complete article published in GIA's Gems and Gemology magazine about these unusual stones. This adventure was very interesting as the team was not only composed of the gemologists working at the Gübelin Gem Lab but it was also including many other gemologists and scientists working in different universities or at GIA. It was a pleasure and an honor to collaborate with such a team.

All the best,

November 25th, 2007 | Keywords:Tanzania , Hughes , Merelani , Morogoro , Mahenge , Songea , Tunduru , Ruangwa , Lendanai , Komolo , Manyara , Lemshuku , ruby , spinel , tsavorite , tanzanite , emerald , alexandrite , tourmaline , moonstone , garnet Travel |
Blog Title: Tanzania 2007

Expedition to gemstones mining areas in Tanzania: (October 2007):

Introduction: This report (in two parts) presents the details of the field expedition to Tanzania lead by the author in October 2007. The author was then working as a gemologist for the Gubelin Gem Lab in Lucerne, Switzerland when his friend Richard W. Hughes (working then at the AGTA GTC Laboratory) asked him if he could help him to visit Tanzanian gem deposits in East Africa. After some difficult negociatiosn with his laboratory the author was allowed to take some holidays and travel to Tanzania with Richard W. Hughes and his group.

The group was composed of Richard W Hughes, the author of "Ruby and Sapphire", Warne and Monty Chitty, Mike Rogers, Guillaume Soubiraa and Philippe Brunot. For the expedition we got the support of Mark Saul (From Swala gem traders) and Abdul Y. Msellem a young Tanzanian broker who was already the author guide in Tanzania during his previous visit in 2005.

We started our visit in the north of the country in Arusha.

We travelled first to Morogoro where we visited some moonstone (I should probably say "peristerite"...) and corundum deposits. Then we continued to Mahenge to visit ruby and spinel mining areas. The visit was interesting as it was just few months after the discovery of several huge spinel crystals. Then we took the road to Songea and Tunduru famous for their sapphire mines. After that we continued to Ruangwa to visit its tsavorite mines. We returned then to the north of the country where we visited the Tanzanite mines at Merelani, emerald and alexandrite mines at Manyara, tsavorite mines near Komolo village and tourmaline mines near Lendanai in the Massai steppe.

Two reports are available on (with the old design of, before Dec 2009)

"Tanzania, October 2007, A Gemological Safari. Part 1: Ruby, Sapphire, Moonstone, Spinels, Tsavorite, Alexandrite: Gems from central and south Tanzania"

"Tanzania, October 2007, A Gemological Safari. Part 2: Tsavorite, Tanzanite, Chrome Tourmaline, Emerald and Alexandrites: Gems from the Massai Land (North Tanzania)"



"Mahenge Spinel"
Eric Saul, (from Swala Gem Traders) presents proudly to the author an exceptional red spinel from Mahenge. The stone weighting more than 10 carats is exceptionally clean and is believed to have been cut from one of the giant crystals found in Mahenge during summer 2007.
Photo: V. Pardieu, 2007

This expedition to Tanzania was in fact very succesful not only for the areas visited and the samples collected but also for the contact created with local miners and traders. Few weeks after the author return in Switzerland, his local contact Abdul Y. Msellem informed him of the discovery of a ruby deposit near Winza.

These expedition reports were also the base of two publications in collaboration with Richard W. Hughes:
- "Working the Blueseam: The Tanzanite Mines of Merelani" about Tanzanite mining at Merelani, available both of and
- "Downtown: Gem hunting in Central & Southern Tanzania" about our expedition to the south of the country, available also both on and

Finally thanks to that expedition Warne Chitty was able to get the samples he needed for his Bsc Thesis in gemology and applied mineralogy (Kingston University, UK).

All the best,

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.