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.


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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)

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:




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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:

Tanzania 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: (visit here)

Part 6) Tanzania:

I would like to first thank ICA Ambassador to Tanzania, Eric Saul and his brother ICA Member Mark Saul, for their time and help throughout this trip, who were so instrumental in the success of this expedition. Thanks to Eric and Mark Saul , we were able to get a very reliable and knowledgeable local guide-translator that had an excellent knowledge about all the mining areas. Besides this, they provided us an excellent car, an experienced driver, and some good information about the local mines and market situation. All this was really helpful for us as few days before arriving in the country, we had to stop the negotiations with the person that was supposed to help us for this trip, so we were without any local contact. Thanks to ICA Vice President Jean Claude Michelou who connected me with the Saul brothers after this problem. This expedition turned to be a great success.

Our schedule was the following:

We arrived in Tanzania on July 27 th, 2005 from Kenya . The main focus for this trip in Tanzania was on ruby and sapphire, but we had also an interest in other gemstones such as spinel, tanzanite, tsavorite, and alexandrite.

We traveled in Tanzania from north to south, trying to visit as many mining areas as possible but as we lost seven days due to the fact that I got malaria in Umba, and my assistant Jean Baptiste Senoble had serious food poisoning in Songea. We had finally to decide to shorten a our trip a little bit and could not visit Ruangwa (tsavorite) and Nanjirinji (blue sapphire) areas in the southern Lindi province and also the Manyara area (alexandrite, emeralds) near Arusha that we kept for our return.

Trip details:

On July 27 th, 2005, after our arrival in Arusha, Tanzania we had an interesting visit to Eric and Mark Saul's company: “Swala Gem Traders” to organize our trip and meet our local contacts.
The trip began on July 28th with a visit to Merelani tanzanite mining area where we went for a one day visit to “Tanzanite One” mine. The visit was very interesting as we had the chance to have Bernard Olivier as guide for our general visit. Mr. Olivier is a very knowledgeable “Tanzanite One” consultant geologist working to complete his PHD on Tanzanite. Then for our underground visit, M Faustus Ruta, the mine geologist and finally we had an interesting meeting with Ian Harebottle, president of “Tanzanite One” group.
The Tanzaniteone mine was not really producing at the time of our visit, but the visit was nevertheless impressive.

(Left to right: With geologist Bernard Olivier, Jean Baptiste 200 meters underground with geologist Faustus Ruta; Photos: Jean Baptiste Senoble, Vincent Pardieu, 2005)

From July 29th to July 31 st , 2005 , we went for a three day expedition to Eric and Mark Saul's tsavorite mine in Lemshuko, a few hours drive from Arusha near Komolo village. The visit was particularly interesting as it is the place where Tsavorite was first found and which is a very important alluvial and primary deposit. We had the opportunity to stay two nights at the mine. We witnessed the work there and spent a lot of time with mark Saul and his team. Mark and Eric Saul's mining operation is now six months old. The mining camp construction is nearly completed and the problem with illegal miners and the lack of water in this arid area looks to be on the way to being solved. Production is currently low but is expected to grow within the next few months. If hard rock mining is also present on the area, Mark and Eric Saul's mine is focusing on the important alluvial deposit were a few months ago several thousands of local miners were working.

(Left to right: With Marc Saul at Lemshuko mine, A fine tsavorite rough, Photos: Jean Baptiste Senoble)

(As Lemshuko is close to Lossogonoi, we went during this three day expedition to visit this mine owned by ROCKLAND , the same group that currently owns the “John Saul ruby mine” in Kenya . We had a great welcome and visit there by the Brazilian mine manager Mr Ebeson. Lossogonoi is as Lemshuko on the way to get seriously in production. Lossogonoi started two years ago to settle the camp and begin the first galleries. Now three shafts and one gallery are in operation and one more gallery is in preparation with thirty-eight full time miners. But the production is not yet here. The mining there looks very serious and the mining conditions were the best we have ever seen in any ruby mine. In Lossogonoi, ruby is found as in hornblende and zoisite. All of the mining there is hard rock mining.

(Left to right: General view on Rockland mine in Lossogonoi, Preparing for a blasting in the mine. Photos: Vincent Pardieu, 2005)

On August 1 st, 2005, we continued our trip to Longido were ruby in zoisite is also mined. We visited the “Mudara Ruby Mine” which is the areas most important operation with a 150 meter deep mining pit and a twenty-six miner team. The production looks to be important, but mainly of carving material. Near the mine, several small scale mines are operated by Massai people. We could see around fifty of them working at the mines or dealing with rubies.

(Left to right: Massai tribesmen trading rubies, Ruby in Zoizite sample. Photos: Jean Baptiste Senoble, 2005)

On August 2 nd, 2005, we left Arusha area for a trip to Tanga in order to visit the Umba valley sapphire mines. There I got malaria and so sadly during the six days we spent there, only one was spent at the mines. We were not allowed to visit the main mine in the area. This was a great disappointment, as we had spent some time with one of the mine partners in Tanga who told us that we were welcome to visit the mine. It was the first time in this four month trip that we were refused a visit in a mine. Despite this problem, we were able to visit some small scale sapphire mines in the area and also some more important garnet and tsavorite operations which saved our day and Umba trip. But we added a new sentence in our field trip vocabulary about a field trip turning bad: “C'est un plan Umba!” (in French…)

(Left to right: Jean Baptiste going down a mine pit in Umba area, Studying a small sapphire near Umba river:
Photos : Vincent Pardieu, Jean Baptiste Senoble, 2005)

After this Umba experience, we went to Morogoro in order to visit the Matombo and Mahenge areas. We decided not to spend time visiting the Kwachaga area where the production is mainly spinel and said to be low and the Geiro, Mkalamo, and Mvomero areas producing, if an order comes, some low quality corundum crystals. We arrived in Matombo district on August 10th and visited several small scales ruby and spinel mining operations near Mwalazi and Kiswala villages. Currently, a few rubies and spinels are mined in these areas as in some other areas formerly more famous like Nyamunguoi and Visakasa. All operations are small scale with three to five miners and illegal as the Morogoro mining officer told us that there is currently no miner paying for any mining license there. Morogoro ruby mining had his glorious day before the arrival of Mong Shu rubies in the beginning of the 90's. Then, the demand for this Tanzanian material dropped ad most miners left to Songea in 1992 and then Tunduru in 1994 when these mines were discovered. Currently around 100 people look to be involved in ruby, spinel, and green tourmaline mining there.

(Left to right: “Spider JB” visiting an underground mine and Vince studying small scale mining in Kiswila area.
Photos: Vincent Pardieu and Jean Baptiste Senoble)

In the Mahenge area, the situation is quite different. Ruby was mined mainly in two areas; Lukande and Ipanko. Several thousand of miners were working in Lukande from ‘87 to '92, but again, after the arrival of Mong Shu ruby, the situation got bad. We visited the Lukande area on August 12th and were able to visit several ruby mines in the jungle around one hour's walk from the village. Less than 10 km from Lukande, in the jungle, two other mining areas (we had no time to visit): Mayote and Chipa are producing stones very similar to Lukande gems: pink sapphires, rubies, and some spinels. The current mining in these three areas is very weak compared to the former situation. Possibly around fifty miners are currently working in the area mining alluvial deposits.

(Left to right: Lukande miner studying a rough ruby, Lukande jungle mine pit. Photos: Vincent Pardieu, 2005)

In Ipanko, things are very different. Ruby mining was the main activity for years. As in Lukande and Matombo, many miners left the area after 1992 mainly to Songea and Tunduru. In Tunduru, some miners learned about spinels a stone that began to have a market and interest and some buyers around the year 2000. Several miners from Mahenge at this time while coming back home were presented some spinels. The stones were selling well and we could see on our visit to Ipanko, on August 11 th, that around 400 miners are currently working there in both alluvial and hard rock deposits along the valley in eight different mines. One mine was using heavy equipment like excavators, but other mines were small scale “box” type. The production was quite important both in quantity and quality and few days before our arrival a fine 4 kg spinel crystal showing some important gem quality areas was found there. Ruby production in Ipanko is very low as only around ten miners are currently mining rubies. Nevertheless, the Ipanko rubies were the best we were able to see in Tanzania. But currently, miners just get more from their work mining spinels than rubies.

(Left to right: Looking at Ipanko mining area; An Ipanko ruby crystal; A miner presenting spinels.
Photos: Jean Baptiste Senoble, Vincent Pardieu, 2005)

Beside Lukande and Ipanko, a third mining area is now producing in Mahenge area at Mbarabanga. We visited the area on August 12th while coming back to Mahenge from Lukande. We reached the mines after a forty-five minute jungle walk and we visit the mine with its owner M Alois Mkongewa. Around 200 miners were working this alluvial deposit located in a valley. Mbaranbanga produces spinels more purple than the Ipanko material which is more pinkish and quite similar to Burmese spinels. The few color change spinels we saw were said to come from the Mbarabanga mines which are also producing some blue spinels.

(Left to right: Mbarabanga jungle mine, Give me this stone for five… Photos: Jean Baptiste Senoble, 2005)

In both mining areas, rubies are found with spinels in alluvial deposits, but the primary deposits, if very close (few hundred meters at Ipanko) are distinct. It was interesting for us to see that the spinel mines at Ipanko show a similar beautiful kharstic mountain landscape to Mogok (Burma) or Luc Yen (Vietnam).

After our visit to Mahenge, we drove for one day to Songea where my assistant Jean Baptiste Senoble got a two day bought with food poisoning. We finally visited the gem deposit on August 17th. The deposit is located around 60 km west of Songea town near Kitai prison. There are three main mining areas at Kitai, Masuguru, and Mukako. The Masuguru area is the main mining area with around 10000 people involved in the mining or the trade. At Kitai around 300 people were said be working, plus the prisoners from the Kitai prison also involved in farming activities. At Masuguru, in Kipara area, two important companies are operating the deposit using some machinery:
- “World Gem Supply Ltd”, directed by Brad Mitchell, an Australian living in Songea from the beginning of the deposit in ‘92.
- “Tansta Mining Co”, the second one located just nearby to World Gem Supply, is a Thai operation.
Both mines employ around 30 to 40 people which is nothing compared to the thousands of locals mining the hills and valleys around these two mines. The production of these mines looked to be important, but mostly the stones are coming in small sizes. Nevertheless, we were told of a twenty carat gem quality stone just days before at World Gem Supply ltd. After our mechanized mine visit, we had a walking visit to jungle mines near Linde (were most of these 10000 miners are coming to sleep each night) and Mbeya where we could see more than 100 people mining. Others areas in the Masuguru district are active at Kwamkesu, Makoro, Litetema, and Kwamahondo. The miners are very scattered on all the hills and valleys in the district.
Historically, the deposit has been mined first from ‘92 to ‘94. Then in '94, many miners left after the discovery of the Tunduru deposit. Songea became a major Tanzanian mining again area after 2000, when the stones were found to have excellent results using the so called “beryllium heat treatment” in Thailand . Currently in Songea town seven Thai buying offices were present along with ten Tanzanian. Songea is now the second most important Tanzanian mining area in terms of number of miners after Merelani. We estimated that around one ton or more of Songea material is currently sent to Thailand per month for treatment in order to produce yellow, pink to orange sapphire, and occasionally ruby.

(Left to right: Women carrying ground to wash in Linde area; Washing at World Gem Supply mine,
Photos: Vincent Pardieu, 2005)

(Left to right: “Lucky” Songea alluvial sapphires; Happy miners in Mbeya mining area, Photos: Vincent Pardieu, 2005)

After our visit to Songea, we left to Tunduru where we arrived late at night. We started our visit early on August 18 th , 2005 in the morning. But we got seriously harassed during our two day's visit. This occurred each time we were in town by the immigration officers which were searching to get money from us. After visiting Thai and Sri Lankan buying offices, we found out that it is common practice there. I want to say at this point that in each of the mining areas we visited, we first went to visit the regional mining officer in order to explain the purpose of our visit and get from him a paper allowing us to visit the mining areas and asked the local people to collaborate with us. In all areas including Tunduru, we were welcomed by the mining officers who were happy to provide us these letters. Of course, I presented these letters to the Tunduru Immigration, but they did not care about it telling me that the problem was our $50 cost tourist visa which is “just good to visit Serengeti but not mining areas, not to speak with people involved in the gem trade and of course not to buy any stone or collect any stone even from the ground.” We should have come with a business visa (also $50 cost) in order to do something other than going to visit national parks!
The local foreigners told us that the situation was much worse in the old days from 1994 to 1999 when between 50.000 to 100.000 persons where involved in gem mining and trading in Tunduru. Things got better with local authorities after 1999 as most buyers left Tunduru or to Ilakaka in Madagascar. Miners could not sell their stones and most of them left to Mozambique or to Ruangwa, a new tsavorite mining area found in 1999 in the neighboring Linde region. Of course, as I said in the Mahenge chapter, some miners went back to Mahenge to begin a spinel business.

Now in Tunduru, besides the small city with its buying offices, we visited the areas only mechanized mine operated by Mr. Sai, a Thai national settled there for many years. Then we visited several small scale mining operations near the Muhuwesi River. The Tunduru mining area is quite different from the other mining areas. It is a very large area in which gems are found in alluvial deposits all around the region along the Muhuwesi River, Lumesule River, and in the Kitoelo area bordering the Selous game reserve. Some illegal mining also occurs in the Selous reserve where the primary deposits appears to be located. The Ruvuma River which is the natural border between Tanzania and Mozambique is also an active mining area. In the Tunduru area, possibly around 5000 miners are scattered mining sapphires, spinels, chrysoberyl and its alexandrite variety, diamonds, garnets, aquamarine, tourmaline, and some rare stones as taaffeite. The number of miners can vary a lot as most of these miners are, in fact, farmers involved in mining during the periods they are not too busy farming. As a result, it is difficult to evaluate the total number of persons involved in the gem production there. An interesting story about mining in Tunduru was that we were surprised to see many small scale peasant miners collecting the alluvial quartz and throwing away the garnets! We were told that there is no local market for garnet but there are buyers for quartz. How strange? In fact, the buyers collecting quartz are trying to get diamonds from ignorant miners who don't know how to differentiate diamond and quartz. During our stay in Tunduru we were presented five diamonds from the Ruvuma River. It was said that the stones were collected this way!

(Left to right: Mr Sai gives some explanations about his mine; A parcel of Tunduru sapphires,
Photos: Jean Baptiste Senoble)

(Left to right: Gem buyer Werner Spaltenstein working in Tunduru; Diamonds and Alexandrites from Ruvuma river; Photos: Vincent Pardieu, 2005)

After our visit to Tunduru, we wanted to visit the green garnet deposit at Ruangwa and the neighboring new blue sapphire deposit at Nanjirinji in the Kilwa Masoko province. This area was known to produce some grayish basaltic blue sapphire, but recently some new stones presenting an excellent blue arrived in the market mostly in small sizes. We saw several parcels of very fine color, without green… but due to the seven days lost from food poisoning and malaria, and the immigration harassment, we did not had enough time to complete our trip and so we decided sadly not to visit these areas and come back directly to Arusha. This took us three long days driving.

I would like finally to recommend to the people more interested about Tanzania to contact Mark and Eric Saul from Swala Gem Traders ( in Arusha , Tanzania. They aware of the current local mining situation in Tanzania and gave us their full support to make this trip a success despite the difficulties we had sometimes encountered. They were gave us with good advice by phone during the entire trip and we really thank them for all their help.

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.