Part 1: ( Click to visit part 1)
Ruby, Sapphire, Moonstone, Spinels, Tsavorite, Alexandrite:
Gems from central and south Tanzania
Part 2: ( Present page)
Tsavorite, Tanzanite, Chrome Tourmaline, Emerald and Alexandrites:
Gems from the Massai Land (North Tanzania)
Texts
by
Vincent Pardieu (Gubelin
Gem Lab, Lucerne, Switzerland)
Photos and maps by:
Vincent Pardieu, Mike Rogers, Guillaume Soubiraa, Richard W. Hughes.
(This temporary page was updated
on July 20, 2008)
This
expedition, even if it
was privately conducted
during my holidays and
financed by the authors,
was supported by the Gubelin
Gem Lab located in
Lucerne, Switzerland,
where I'm working as gemologist
at the time of the expedition.
I invite you to continue now with our October 2007 expedition: After our visit at Morogoro, Mahenge, Songea, Tunduru and Ruangwa, we continued
to Dar es Salaam for a long drive
and then the following day to Arusha.
During my first visit in Tanzania
with Jean Baptiste Senoble in August
2005 we visited what is probably the most modern colored gemstone mine in the world: The Tanzanite One mining operation at Merelani. We had one very interesting day visiting this high tech mine.
Back
in Arusha we decided first to
go to visit the Merelani Tanzanite
mines located close the the
majestic Kilimanjaro mountain. But this time we were not willing to return to visit Tanzanite One, but instead we wanted to visit some of the local mining operations at the bloc D in order to have a first hand experience and a better understanding of Tanzanite mining.
In 2005 I visited with Jean
Baptiste Senoble the Tanzanite
One mining operation, which
is the most modern colored gemstone
mining operation I ever visited.
It was a very interesting visit
but of course Merelani is not
only about modern mining methods
and we wanted also what was
presented to be the dark side
of Merelani with our own eyes
.
We decided to visit Merelani
Bloc D. Merelani is divided
in 4 main blocs named A to D.
It is Tanzanian main mining
area with possibly between 40.000
to 70.000 people mining and
living here. 5000 to 6000 miners
were told us to work at the
Bloc D which is the area where
the deepest tunnels are found
as the gem deposit gets deeper
from Bloc A to Bloc D. Tanzanite
One is mining the Blocs B and
C. We started our visit by the
local mining officer office
in order to get their support
in our project to visit the
mines. We then left Merelani
city and drove to the Bloc D.
On the way we passed near Machakecho,
a large mining area located
between Merelani town and the
different mining blocs where
many small miners were working
a secondary deposit. The area
was quite interesting as we
were lucky to have a nice weather
and could take some photos of
Tanzanite mining with the Kilimanjaro
on the background. We drove
then around the Tanzanite One
mine to arrive in the Bloc D.
A short video showing a 360 degres view from one of the Merelani explosive storage facility over the region and the Tanzanite mines: Under the Kilimanjaro mountain the Machakecho area is clearly visible, and then on the hill, the Tanzanite One mine.
Video: Vincent Pardieu.
We were able to visit the "Kikuyu"
mine in which 60 miners were
working underground by teams
of 30 with 6 hours shifts. The
mine manager Nixon Monga is
24 years old. He is managing
the mine for 9 years since the
death of his father with the
help of two partners. The mine
start with a vertical pit about
100 meters deep with a wooden
ladder. then several tunnels
about one meter wide on one
meter high are going deep underground
about 200 to 300 meters to reach
the mining head. Nixon Monga
told us that miners were working
for the last 2 years but nearly
no stones were found and the
work is becoming more and more
difficult at the tunnels are
deeper and deeper.
We visited the mine twice: First
on October 20 and then again
on October 23: We could witness
the miners shift which was impressive
as the miners coming back from
6 hours of underground work
were coming out of the pit completely
covered by graphite powder,
rushing to get their small pack
of milk. On October 20 we decided
to went down into the mine.
Guillaume Soubiraa went first
and I followed. But once on
the vertical ladder over the
dark vertical pit I had the
bad idea to ask how deep was
the pit.
One of the miner answered about
180 meters. 180 meters vertical
pit on a dusty wooden ladder????
I was suddenly remembering a
similar experience I had in
Mogok went I went down about
80 meters underground in Bawpadan
mine on wet wood: Crazy experience
and here it was more than double!
No way!
I got a sudden vertigo feeling
and thought about my wife who
asked me before to leave on
that expedition to be careful
as she was not willing to become
yet a widow.
I decided not to go down, but
Guillaume Soubiraa and Micheal
Rogers were already on the way
down.
We waited them to return to
the surface for 2 long hours.
which were not useless as we
could speak with the miners
and take some photos around.
When Guillaume and Mike returned
to the surface covered of sweat
and graphite they needed 5 minutes
to be able to stand and speak.
But the first thing they said
was
"Vince: You have to go
there, it is just incredible"...
Damn!: That was exactly what
i was not willing to hear.
I asked then about the vertical
pit and the wood. They then
told me that 180 meters was
exaggerated, the vertical pit
was possibly about 100 meters
but there were several places
where it was possible to rest
a bit and the wood and the mine
were dry. Then Mike told me
that his camera got broken in
the deep of the mine, that was
meaning that we had no photos
or short movies at all.
Michael Rogers and
Guillaume Soubiraa,
two young gemologist
recently graduated from
AIGS in bangkok are
rexaminating rough Tanzanite
after spending 2 hours
underground with the
Merelani miners.
On the following photos
they take the pause
with the Kilimanjaro
on the back side with
our guide and friend:
Tanzanian Gem broker
Abdul Amsallem.
Finaly they are getting
very affectuous with
Richard W.Hughes.
Happy birthday Richard!
Ok we then decided that instead
of visiting the Ngorongoro crater
2 days later we would return here
with some cameras able to take
photos there.
On
October 23 I returned then to
Merelani with Guillaume Soubiraa
and Philippe Brunot. Philippe
was able to protect his video
camera and both Guillaume and
I had a camera.
Ready to go underground? Philippe Brunot has prepared his camera with Guillaume Soubiraa they looks ready for his second underground visit... As the Merelani undergound is full of graphite dust, a scarf seems to be a good idea.
Video: Vincent Pardieu.
We went down for nearly 3 hours
in the deep of the mine. At the
time of our second visit the miners
were not digging but taking out
all the mine waster. Nevertheless
going down the 100 meters deep
vertical mining pit was a daring
experience: Of course we had no
ropes or helmet and I was praying
that nobody would fall in the
pit while we were going down as
in that case we would all fall
in the darkness of the mine pit.
But everything went fine and I
could see that the wood ladder
was strong. Arriving in the deep
of the vertical pit we started
then to crawl in the tunnels which
were very irregular going up and
down. The task was difficult for
me as these tunnels were not build
for 1.90 meters tall guys like
me: they were not more than 1
meter high meaning that i was
not even able to walk on four
legs but I had to crawl all the
time and they were barely wide
enough for me to pass.
I met in one occasion some miners
going up while I was going down
and he had to pass over me covering
me with graphite dust. The atmosphere
was also from difficult to impossible
to break with the mask we had
and soon we had to take them out
as breathing graphite was in fact
more convenient that not breathing
at all. We could also understand
why the miners were not willing
to weir helmets: First the tunnel
top was solid rock and they were
so narrow that wearing a helmet
would become rapidly very annoying.
In fact helmets and masks are
just not very convenient when
you crawl like a rat underground
in very narrow tunnels.
After about one hour visiting
some secondary galleries we arrived
at the main mining area which
was wider and slightly higher
than the tunnels we were using
so far. The wonderful surprise
was that on the floor there was
a hole from which fresh cold air
from the surface was coming. It
was a pure wonder to breath it
after one hour breathing hot graphite.
At the mining room, the miners
explained to us what they were
doing, they were very excited
to show us the veins they were
mining following the pyrite and
the graphite.
We could then see in their eyes
what was motivating them to work
under such tough condition: Hope,
hope to hit a gem pocket and become
rich as it happened in the past
to others. Miners told us that
staying in their village or in
a city slum, they had no chance
to have a future, but here with
hard work and some luck they might
get enough money to get a good
life. I was thinking that hope
was may be a short cut to deception
but it for sure help people to
endure hard life!
After nearly hour hour crawling in the narrow Merelani tunnels, we finaly met miners which were busy cleaning the mine after few days of production. We were very tired but happy to take some rest there with the miners. The miners were happy to show us what they mining even if their English was very weak. Tanzanite is hard work... a a lot of hope!
Video: Vincent Pardieu.
After
nearly 3 hours we returned to
the surface, going back was much
more difficult than going down.
I had to stop many times to be
able to breath. The tunnels were
dry, just dusty with graphite.
The miner helping me Izrael Deo,
told me that it was normal as
it was for me the first time.
I was thinking: Could people get
used to that? He was smiling.
I had no answer as seconds after
we reached the wooden ladder of
the vertical pit. I started to
climb. I was tired and my only
focus was just not to fall. Meter
by meter, as safely as I could.
The air was becoming better and
there was this round of light
over my head shining like heaven.
After few minutes we were all
back to the surface, completely
covered of graphite, completely
tired but safe. I was lying on
the floor thinking that I would
never do that again: The miners
were smiling and laughing. Within
few hours they would all go down
again, not to visit the mine but
to work, to break rocks and to
mine small crystals. Hard work
for one day, one wealthy guy somewhere
will be able to offer a lovely
stone to the woman he love. Hope
and hard work turned into love
and cash? Yes, this is Tanzanite...in
the best case.
Few
weeks ago i read on newspaper
that due to the heavy rains several
mines in Merelani were flooded
and many miners died deep underground.
I was reminding myself crawling
in these tunnels: What if these
tunnels instead to be dry were
wet and slippery and what if water
was entering the mine? Well, simple:
I would have also probably died
there: Terrible! I had no problem
to imagine now what were probably
these miners last instants.
But tomorrow probably new miners
will continue to go down and dig
Merelani hill to get Tanzanite
and these huge tsavorites. Incredible
stones, incredible mines and mining
conditions and incredible men
to volunteer for such a hard job!
I have a lot of admiration for
the Merelani miners I met in this
mine, and particularly to Izrael
Deo and Tobias Stanslaus, the
two miners who took me down there
and then back to the surface.
Izrael Deo was a young educated
Tanzanian speaking good English.
He told me that he decided to
stop the school to come mining
with his father because he wants
to get money, to learn about gem
mining and to get a good life
in the future. Each time I see
a Tanzanite or a large Merelani
Tsavorite I just think about you
guys! About you and about these
tunnels! I do wish you all the
best.
After
our expedition to Merelani we
decided that we also had to explore
East African green gems: We decided
to visit then the Manyara emerald
and Alexandrite mines, the Tsavorite
mines near Komolo village at Lemshuko
and also the chrome Tourmaline
mines near Lentanai...
During
our last visit in 2005 we visited
already the Tsavorite mines at
Lemshuko which are managed by
mark Saul the son of the famous
John Saul who discovered rubies
in Tsavo, Kenya during the 1960's...We
returned there and were able to
see the progress after two years:
The mining plant which was under
construction in 2005 was operational
during our visit on October 21
and we could witness actual mining.
On the way back from the mine
we could see the new Komolo school
which was financed by the ICA
(International Colored stone Association),
the French Gemological Association
groups visiting Tanzania recently
and by Swalagemtraders, Mark and
Eric Saul company . The school
was to open on Dec 9th 2007, the
Tanzanian Independence Day.
A video showing one of the plants used at lemshuko to concentrate the gem gravels: At Lemshuko Tsavorite is mined from a detritic deposit. The gems are associated with a dry ground . In order to save water, it is necessary to eliminate the dust before to wash the gem rich gravels. This plant eliminate dust and large rocks... Clever!
Video: Vincent Pardieu.
A second short video showing the Lemshuko washing plant. There the gem rich ground, which was first contentrated at the dry plant, is washed. The washing plant is associated with a water reserve. In case of shortage a truck can be used to bring water.
Video: Vincent Pardieu.
A short video showing our group witnessing the harvest at the Lemshuko washing plant: The Tsavorite found are placed in a simple bottle by the mine manager...
Video: Vincent Pardieu.
We were very happy
to see Mark Saul collecting
a large piece of rough
tsavorite from the jig.
It was a good occasion
for me to shoot one
of my favorite photos.
Thanks Mark!
On October 22, we left to the
lake Manyara in order to visit
the emerald and alexandrite
mines described in the past
by Dr E. Gubelin. We were told
that out of nine mining operations
with licence four mines are
currently in operation with
about 10 workers per mine. We
were able to visit two of these
mining operations: the Pengo
mine and a second small mining
operation run by 3 young Tanzanian
in their 20's. Both mines started
with a pit, then it was going
underground with a small pit
and then tunnels. The tunnels
were a little bit larger than
in Merelani and only about 10
to 50 meters deep. The miners
were friendly, shared with us
a little bit of food and presented
also to us some emerald and
alexandrites they had mined.
The visit was nice, the area
was beautiful, green. Baboons
and velvet monkeys were visible
around the mine and many signs
were also showing that elephants
were also commonly visiting
the area.
A view over the Pengo
emerald and alexandrite
mining area in Manyara.
Going down the Pengo
Emerald and alexandrite
mine at Manyara. The
mine pit is not very
deep about four meters
and then a gallery about
20 meters long bring
to the mining place.
During our visit it
was several days nobody
was working an the tunnels
were then half flooded.
Nevertheless we could
see some tiny emeralds
on the mine walls.
Ayubu Juma, Isack Elesamia
and Suleiman Mohameed
were very proudly mining
emerald and alexandriteat
Manyara. Tough young
guys!
On October 24, we decided to go
to visit the main green tourmaline
(which can be called in some rare
cases "chromdravite"
or "chrome tourmaline",
if it is chromium rich, or more
commonly dravaite or uvite if
the origin of its green color
is more due to iron or vanadium)
mining area in Tanzania: Lendanai.
This area was told us to produce
about most of the Tanzanian "chrome
tourmaline" production, but
it seems that in fact less than
5% of its green tourmaline contain
chromium and thus can be called
"chrome tourmaline".
The main other Tanzanian green
tourmaline mining areas producing
are the Umba, the Matombo, the
Leletema hills areas. Tanzania
is not the only producer in the
area, "chrome tourmaline"
is also produced in Kenya (Tsavo
area), usually associated with
tsavorite and rubies, in Madagascar
and Zambia. Recently I heard from
Chanthaburi people that a new
deposit was found in Mozambique
producing some fine bright material.
We took the road to Lossogonoi,
the ruby mine we visited in 2005.
The operation run by Rockland
is currently closed as it was
not profitable, the cost of mining
with modern techniques was too
high compared to the value of
the rubies collected. Interesting
thing to notice and remember when
prices for gas are going higher
and higher. If local small scale
mining will probably continue
to be present, as the only necessary
things is to have men with time
to spend mining, hope and the
motivation to get a better future
for them and their families working
hard, it seems that modern mining
using machinery will be only profitable
in few very rich deposits when
prices for the gems produced will
be good enough.
Few kilometers after
Lossogonoi we arrived
at Lentanai village
dominated by Lossogonoi
mountains. The village
was scenic, many Massai
were present with hundreds
of cows, it was interesting
to learn that the Massai
were the main gem dealers
here as in many area
of northern Tanzania:
They travel the land
with their cows and
are involved in the
gem trade. When they
make profit they buy
cows, when they need
to buy gems, they can
sell few cows, their
main goal and their
capital remain cattles.
It is something interesting
as if the gem trade
is not going well they
still have their main
activity to continue
to live.
This is their strength and it
is an interesting aspect of the
gem trade in Northern Tanzania.
And believe me they are really
tough dealers as when you know
how to bargain for cattles (or
when you know how to bargain with
tourists.) it is not difficult
to bargain for gems: Guillaume
Soubiraa willing to buy some few
rough green tourmaline from the
Massai was able to understand
that very rapidly, hands on! Tough
people but it was a great experience.
A short video showing Guillaume Soubiraa in some Chrome Tourmaline buying action with Massai gem dealers near the mines at Lendanai.
Tough bargaining was ruling!
Video: Vincent Pardieu.
At Lentanai it was
interesting to see that
in the same mining area
several type of mining
take place: Some groups
of miners are working
for the mine owner providing
food and tools, in that
case, the owner of the
mine can get 75% of
the production while
the workers get 25%.
Some Massai groups are
operating differently,
they give 30% to the
owner of the mine in
order to be allowed
to work but come with
their own food and mining
equipment.
Around Lendanai mining started
at the end of the 1960's, we heard
about 12 mining operations for
green tourmaline involving about
500 miners. Mining was told us
to have been at its best during
the 1990's then it started to
go down. The global mining area
seems to be about 15km by 10 km.
A short video showing a 360 degres view from one of the Chrome Tourmaline mine we near Lendanai. It was a beautiful view point over the Massai steppe and into the daring mining trench reflecting more than 30 years of mining...
Video: Vincent Pardieu.
Most of the mines are underground.
The miners told us that they were
following mica and quartz veins
in marble in order to reach small
pegmatite bodies where green tourmalines
are collected. 50% of the production
was told us to be gem quality,
with stones from 5 to 10 grams
representing about 25% of the
production, but stones under 5
grams rough are the most common.
A short video showing a glimpse of the beautiful drive we had returning from the Chrome Tourmaline mines to Arusha. We were driving toward the scenic Kilimanjaro mountain as the sun was going down. Just a beautiful drive!
Video: Vincent Pardieu.
After returning to Arusha we
left rapidly Tanzania to Kenya as Richard W.Hughes
was very concerned about the fire
ravaging the area where he was
living in California. His family
was evacuated but everything was
finally fine for him, hopefully!
That was the final step of a very intensive month traveling all around Tanzania to meet its incredible gem wealth!
Last news from Tanzania:
Nov 2007: New speassartine garnet
deposit near Loliondo: It was
interesting to hear that one month
after our departure an interesting
spessartine garnet deposit was
found near Loliondo village near
the Serengeti close to the Kenyan
border. The material was of fine
color but was most of the time
very included. Nevertheless beautiful
crystals were found. Speassartine
from Loliondo were well noticed
at Tucson in Feb. 2008. In april
2008 when I last visited Tanzania
the activity at Loliondo was reported
to be much weaker than in the
past few months as many miners
moved to Winza to mine rubies.
(More
info about this new spessartine
deposit)
November 2007: New ruby deposit
near Winza: In November 2007 between
Dodoma and Morogoro, a ruby rush
happened in Mpwapwa district,
near the Winza village. The area
seems to be an old ruby mining
deposit recently re discovered
as mines are indicated at the
axact location of the current
mining village in old maps from
the 1960's. The deposit was reported
to me in January 2008 by Abdul
Msallem who visited and worked
in the area in December 2007.
It produce rubies looking quite
similar to Thai rubies but also
pink, pinkish orange and blue
stones. One of the most interesting
features of these stones looks
to be the strong blue color zoning
they present. Several attractive
cut stones from 1 to 15 carats
told to be from this deposit were
seems recently at the Basel gem
fair. From April 16 to 21 2008, I visited and studied the Winza
deposit with gemologist Jean Baptiste
Senoble, where about 4000 people
have rushed.
Special thanks: To my traveling companions: Richard W. Hughes, Guillaume Soubiraa, Philippe Brunot, Michael Rogers, Warne and Monty Chitty, for their friendship and great attitude during this 3 weeks long expedition, to our guide: Abdul Amsallem for all the knowledge he shared with us and all the help provided, to our drivers from Fortes safari (Arusha, Tanzania): Moussa and Abel, for their great attitude and professionalism, to our ICA Friends in Tanzania: Mark and Eric Saul (from Swalagemtraders) for their welcome and support, and last but not least to all the Tanzanian authorities, miners and brokers who welcomed and helped us: It was much appreciated!
I hope that this report will be useful to all people involved in the gem trade from the production areas in Tanzania to the consuming markets and for all gem lovers around the world.
All the best,
Tanzania, October 2007: A Gemological Safari
Part 1: ( Click to visit part 1)
Ruby, Sapphire, Moonstone, Spinels, Tsavorite, Alexandrite:
Gems from central and south Tanzania
Part 2: ( Present page)
Tsavorite, Tanzanite, Chrome Tourmaline, Emerald and Alexandrites:
Gems from the Massai Land (North Tanzania)
Interesting Links, articles, maps and books about gemstones from Tanzania: (to be completed)
Interesting Links about rubies from the new Winza deposit: - Feb 05, 2008: Frist announcement about the new ruby and sapphire discovery near Dodoma by the author on the GemologyOnline gemological forum
- May 03rd 2008, first serious public release about rubies from Winza: SSEFnewsletter_may08
- May 05th 2008, GIA Insider published an article about Winza by SSEF
- May 06th, 2008, The Gubelin Gem Lab make a public announcement about rubies from Winza in its newsletter:
- May 26th 2008, GIA Insider published a short article by Brendan Laurs and Vincent Pardieu about Winza
- June 03rd 2008, the ICA put online its InColor Magazine: with an article from JB Senoble about our common expedition to Winza and another gemological article by SSEF about these Winza rubies. - June 05th 2008: GIT put on its website a short study about Winza rubies:
- July 04th 2008, Diamond Rappaport Report, Vol 31, N26, p173 to 175: "Field Report from Winza" by Vincent Pardieu and Dietmar Schwarz, Gubelin Gem Lab.
Recommended Articles from Gemological Magazines:
- "Alexandrite from Lake Manyara, Tanzania", by E.Gubelin, Gems and Gemology, Fall 1976
- "Garnets from Umba valley, Tanzania: Is there a necessity for a new variety name?" by K.Schmetzer, Journal of Gemmology, 1981, XVII, 8
- "An Unusual garnet from Umba valley, Tanzania" by K. Schmetzer, Journal of Gemmology, 1982, XVIII, 3
- "Reddish-brown sapphires from Umba valley, Tanzania" by M. Gunawardene,, Journal of Gemmology, 1984, XIX, 2
- "Korunde aus dem Umba-Tal, Tansania, by H.A. Hanni, Z. Dt. Gemmol. Ges., Oct 1986
- "On corundums from Umba Valley, Tanzania" by H.A. Hanni, Journal of Gemmology, 1987, 20,5
- "Well-formed tsavorite gem crystals from Tanzania" by R.E. Kane, A.R. Kampf, H.Krupp, Gems and Gemology 1990
- "New rubies from the Morogoro area, Tanzania" by H.A. Hanni and K.Schmetzer, Gems and Gemology, Fall 1991
- "Gem quality green Zoisite" by N.R.Barot and E.W. Boehm, Gems and Gemology, Spring 1992
- "Lamellar inlcusions in spinels from Morogoro area, Tanzania" by K.Schmetzer and A. Berger, Journal of Gemmology, 1992, 23,2
- "An examination of colour change sapphire from Tanzania", by R.C. Kammerling, M.L.Johnson, Y.Liu, The Australian Gemmologist, Second Quarter 1996
- "A new colour change effect" by A.Halvorsen and B.B. Jensen, Journal of Gemmology, 1997, 25, 5, 325-330
- "Sapphire and garnet from Kalalani, Tanga province, Tanzania", by A. Siefert and J. Hyrsl, Gems and Gemology Summer 1999
- "Gem Wealth of Tanzania" by D. Dirlam, E B. Misiorowski, R Tozer, K.B. Stark and A.M. Bassett, Gems and Gemology, Summer 2002
- "Chemical fingerprinting of some East African gem rubies by Laser Ablation ICP-MS" by A.H. Rankin, J.Greenwood, and D. Hardgreaves, Journal of Gemmology, 2003, 28,8,473-482
- "The ICA 2006 World Colored Gemstone Mining Report", Incolor Spring 2006.
- "My road to the discovery of Tsavorite" by C. Bridges, from "Into East Africa, a Journey to the Source", Incolor 2007
- "Tanzanite: Its discovery and early days" by J. Saul, from "Into East Africa, a Journey to the Source", Incolor 2007
"Gems News" and other "Gem News International" from Gems and Gemology : (to be completed...)
- "Tanzanian spinel", Gems and Gemology, Fall 1991, p183 (about Mahenge spinels)
- "Update from Tanzania", Gems and Gemology, Fall 1991, p183 (about Longido ruby)
- "Large Tsavorite garnet from Tanzania", Gems and Gemology, Winter 1991, p258-259
- "Update on Tanzanian mining", Gems and Gemology, Winter 1991, p262 (about Tanzanite at Merelani)
- "faceted ruby from Longido", Gems and Gemology, Fall 1992, p203
- "Ruby mining near Mahenge, Tanzania", Gems and Gemology, Summer 1993, p136
- "Sapphires from Tanzania" Gems and Gemology, Spring 1995, p64-66
- "Sapphires and other gems from Tanzania", Gems and Gemology, Summer1995, p133-134
- "Update on Tanzanite mining", Gems and Gemology, Summer 1996, p135 (about Tanzanite at Merelani)
- "A new source for Tsavorite", Gems and Gemology, Summer 1999, p151-152 (about Ruangwa)
- "Ruby from Songea, Tanzania", Gems and Gemology, Winter 1999, p215
- "Another source of bicolor sapphire, Tunduru, Tanzania", Gems and Gemology, Winter 1999, p215
- "Update on Tanzanite mining by AFGEM", Gems and Gemology, Winter 2003, p337-339
- "Large tsavorite and green grossular from Tanzania", Gems and Gemology, Spring 2004, p72-73
- "Pink to pink oragne spinels from Tanzania", Gems and Gemology, Spring 2004, p71-72
- "Control on Mineralization in Bloc D' of the Merelani Tazanite Deposit, Tanzania", Gems and Gemology, Fall 2006
- "Geology and Mining of Southern Tanzanian Alluvial Gem Deposits", Gems and Gemology, Fall 2006, p107
- "Transparent dumortierite and sapphirine from Tanzania", Gems and Gemology, Winter 2007, p379
Interesting
Books about Rubies, sapphires, spinels and Gemstones from Tanzania :
"Gemstones from East Africa" by Peter C. Keller (1992)
"Corindon et Spinelles" by F. Cresbron, P. Lebrun, J.M. Le Cleac'h, F. Notari, C. Grosbon, J. Deville, Mineraux et Fossiles, Hors Serie No.15, Oct 2002
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Important Note: Vincent Pardieu
is an employee of Gübelin
Gem Lab Ltd (Gübelin), a gemmological laboratory
based in Lucerne, Switzerland. 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 Gübelin. Gübelin
takes no responsibility and assumes no liability for
any content on this website nor is Gübelin liable for
any mistakes or omissions you may encounter. Gübelin
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