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Chrome
tourmaline from Tsaniria.
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In 1989, Mr.Tombomana finds
stones, green emerald color by moving large stones to build a tomb. A
little bit later he leaves his area of Andrambali, the discovery is
forgotten.
In 1992, I see a
chrome tourmaline of big size in the hand of an Indian tradesman of
Amboasary, 150 kilometers far
from there.
One Tombomana by name is back home
in 1994, he profits to begin research of tourmalines again. In October
1995, the young man is in Ampamata, 190 kilometers far from there, where
he practices his job as a teacher. It
is there that we meet him and it is at this period that the deposit of
Tsaniria is exploited, it will produce small quantities of chrome
tourmalines during two years.
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The occurrence of Tsaniria in 1995.
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Antandroy tomb.
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The
Antandroy tribe living in the south
of
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Madagascar,
is devoted mainly to the breeding of
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animals,
especially the zebus. One of its ancestral
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habits
drive them build houses increasingly smaller
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than those of the preceding generation. On
the
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other hand, when an owner of zebus die, the herd
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is
entirely sacrificed, the horns of the animals will be
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used
to decorate his luxurious and last residence.
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TOURMALINE
CHARACTERISTICS
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·
The spessartite garnet. |
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Exploitation
of spessartite garnet in tanety
(grounds bordering the river) in Ambohimarangitra
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The
first quotations of spessarites in the area were made by the geologist Henri Besairie in 1946. |
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The
French colonists exploited gold and garnet in the Besafotra river between
Ankaboka and Ambohimarangitra, place located 25 kilometers from the
nearest village. |
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In
1972 a bulldozer dug a track on 30 kilometers to Ankaboka in order to exploit
there the spessartites to the edge of the river, at the place said Beakoho,
this during one year. |
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Then,
the spessartite remained forgotten until 1996, date on which
it was extracted from the river and the adjacent grounds to provide the international market temporarily. |
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Spessartite from |
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Ambohimarangitra. |
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SPESSARTITE |
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The
deposit of spessartite is lying behind |
| the
hill of
Ambohimarangitra
located at the |
|
center
of the
picture
on the line of horizon. |
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(At the
foreground,
the
Besafotra river.) This |
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deposit is
exploited in
alluvium
and is located in |
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the
geological system
called
"Vohibory", |
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composed
mainly of gneiss
with
amphibole
and of |
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green
schists, the
precious orange
garnets result |
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likely
from
sodolitic pegmatites. |
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| GARNET
DATA |
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| · Liddicoatite
tourmaline. |
Rubellite,
Anjanabonoina. |
Workers
in Anjanabonoina. |
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Anjanabonoina. |
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· Yellow
orthoclase from Itrongay. |
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The
deposit of Itrongay
in the south was known for a |
| Found
in
eluvium, but comes from a pegmatite with |
long
time to have been
the single yellow orthoclase |
| diopside
of a very special type, which presents the single |
producer in the world. It is into 1988 that
two new |
| characteristic
to be made of transparent minerals only. |
deposits were discovered in the vicinity. |
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ORTHOCLASE
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·
Malaya
garnets found in leptynite in 1996.
This
stone shows an exceptional capacity to restore the light, thanks in
particular to its high refractive index, especially under
not very enlightened condition.
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This
day of July 1996, the leptynite, mother rock of the malaya, was so hard, that
hand work appeared unreasonable to its discoverers, some samples
nevertheless were extracted. |
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is in September 1998 that an eluvial deposit was found approximately
one kilometer far from the first one. The gold rush did not last, because the thickness of the ground containing the stones was modest and the deposit
became quickly exhausted. In addition, the simultaneous discovery of
Ilakaka sapphires attracted there people coming from all over the island at
the end of 1998, the deposit was thus abandoned.
Malaya
Garnet Discovery |
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MALAYA
Malaya's chemical composition is
a mixture of many general Garnet types, including Grossular, Spessartine,
Almandine and Pyrope. ( Mn3Al2(SiO4)3, Manganese
Aluminum Silicate.) RI: 1.76 - 1.78
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| ·
Emeralds
from Morafeno and Ambodibakoly (East)
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The
emerald occurrence from the East coast, provided |
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quality
stones since 1975
until 1993. Their professional
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| exploitation began in the
middle of the eighties.
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| The first listed discovery
was reported in 1911 by the |
| geologist
Levat. Then, during the colony, a settler called |
| Bourgeois discreetly exploited the green stones which |
| with the statement of the Madagascans made his |
| fortune.
At the time of their
departure, the settlers who |
| worked
emerald mines in the area, warned the natives |
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against
the bad spirits which could be in the holes. Thus, |
| The emeralds of this area are
located in the geological |
the gems slept within 15 years. |
| group called Ampasary. (silico -
aluminous and calco - |
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| magnesian series) note the
abundance of gneisses and |
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The
area of Kianjavato, village located near |
| mica schists, heterogeneous
migmatisation of épibolite |
the emerald mines, is in what it
remains of the |
| type. |
rain
forest of the East coast. |
| The bed rock of the emeralds is a
biotite mica schist |
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| crossed by
talc and chloritoschist, metamorphized |
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| by the contact of a close mass of
granite containing |
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| pegmatites. |
| These hyperacides intrusions gave
beryllium oxide, |
| alumina and silica thus source of
beryllium, they are |
| located near ultrabasic rocks in
particular the |
| serpentine ones, green biotic schists,
source of the |
| necessary chromium contribution. The calco
- |
| magnesian serie results in gneisses more or less |
| migmatic, with diopside, garnet, calcite,
sphene, and |
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sometimes scapolite, more rarely by pyroxenites |
| wernerites
and limestone. |
| The silico - aluminous serie is
presented in the form |
| of quarzites at sillimanite, with or
without graphite. |
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| This serie is located preferably
at the base of the |
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| group. |
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Visit
the emerald forest. |
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GEM ADVENTURE ( Novel ) |
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©
All of the pictures on this
website have been shot by
gggems.com Text written by Alain Darbellay. |
|
