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Sapphires
from Andranondambo, discovered in
1991. ( South-Eastern Madagascar )
  
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In
1658, Flacourt, the governor of Fort-Dauphin, mentions
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sapphires
in southern Madagascar.
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In
1808, Barthélemy Hugon writes that in the valley of |
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Ambolo there is a so beautiful stone and so rare that his |
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lapidaries have not
been able to recognize it and it was |
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above of all that is not diamond.
... In 1991, at the time of |
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the great dryness in the south,
sapphire samples are found, |
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several centuries after their first discovery. The son of Mrs. |
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Dauphine, innkeeper in
Tranomaro,
main village of the |
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valley, was among the prospectors. |
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Actually, one of the most beautiful
sapphire quality in the |
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world is just leaving ground. |
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The
Tranomaro area is characterized by an |
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extreme
calcic and
magnesian paragneiss abundance: |
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Gneiss with diopside, plagioclasites,
pyroxenites, |
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wernerites,
wolastonite marble, with
varied |
| leptynites, generally with
garnet, kinzigites,
quarzites. |
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One finds there rather
frequently syenitic
gneisses |
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or lamboanites. Gneisses of injection are
very |
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frequent. |
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The typomorphic
minerals are: basic diopside, |
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scapolite,
calcite, plagioclases, |
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wollastonite, garnet,
cordierite and corundum. |
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East
of Tranomaro, arteritic and eyesys injections |
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assign
gneisses
at leptynites. Cordierite gneiss stripes |
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are deeply
injected
bed by bed, the injection has |
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introduced magnetite
in
abundance.
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Wollastonites form ptymatic lenses with |
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Marohotro, 8 km. south of
Andanondambo. |
folds
very tortured at the middle of the limestone. |
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The
sapphire on the left comes from Ambandanira, and
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Note:aluminous
anorthites or sakenites. |
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that on right-hand side
from Maromby |
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(area of Andranondambo)
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Holes
can reach 20 meters depth. |
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| Sapphires
from Ilakaka. |
One
of the various holes in sandstone forming |
| ( South-Western
Madagascar ) |
the
deposit of Ilakaka discovered in to 1998. |
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| Blue
sapphires , pink and violet, Ilakaka area. |
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ISALO SANDSTONES. |
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The
white sandstones of Isalo present imposing |
| stratifications
intersected
with gravel beds and |
| small conglomerates. |
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These
soft sandstones resisted to erosion and taken a |
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ruiniform relief because the presence of
braces siliceous |
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veins. |
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The
mineral-bearing deposits include : a deposit of generally |
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classified
gravels, the richest part and larger elements |
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being
at the base of the bed - rock. |
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The far-south of Madagascar, semi-desert, does not present |
Polychrome
sapphires from Iankaroka |
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any asphalt road yet, dust and trepidations are
the daily |
| discovered in 1990. |
lot
of any traveller. Sunsets
and the natural life of its |
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inhabitants
offer an appreciable compensation. |
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| This
sapphire occur in a contact |
| zone
between granites and |
| migmatites. |
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| It
is found in its bedrock. |
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Rubies
from Ianavoha. |
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| (Southern
Madagascar.) |
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Rubies
in syenite from Andranomilitsy. |
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Ruby
from Andranomilitsy (Vohitany) |
Syenitic-nephelinic
vein of rubies in Andranomilitsy.
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In Soamiakatra, rubies were sold with sunglasses. |
The
Mayor of Soamiakatra in 1989, (East of Antsirabe.)
Rubies
from Soamiakatra in the highlands.
Here,
rubies are always found in alluvium.
MADAGASCAN CORUNDUMS
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| Ambondromifehy
( Diego ) |
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| BLUE SAPPHIRE NATURAL COLOR |
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| Sapphire
from Analafady (Ambondromifehy) North. |
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The Ambondromifehy alluvial deposit is exploited since |
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1996.
It is located in a Jurassic limestone, but the origin of |
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sapphires
is in alkaline basalts from the close volcanic zone. |
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Mahatsara (
Ambondromifehy) |
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The
consumption of khat “a kind of narcotic plant” is quite |
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common
in the
Diego-Suarez region,
people can be very |
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| dynamic. |
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| This
deposit produced mainly blue sapphires, but also some |
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| bi-color,
some yellow sapphires, and rough material to cut in |
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| cabochon
and,
star sapphire too. |
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| Didy
Sapphire & Ruby Rush 2012 |
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| Within
2011, sapphires from Ambatovolana
reached |
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| the
capital Antananarivo sporadically, brought there |
| by
gold miners. |
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| Ambatovolana
is located 25 kilometers south-east of |
| the
village of Didy, which is located 45 km.south-east |
| from
the town of Ambatondrazaka. (Tamatave region.) |
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| On
July
18th 2011, a lapidary from the
Capital reveals to |
| me
that the extraordinary sapphires in his hand
come |
| from "Ivoloina" a new deposit located in the region of |
| Brickaville,
on the road to the port of Tamatave |
| (Toamasina.)
I
buy the stones. |
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| "
The
deposit on the Ivoloina river is actually located 40 |
| kilometers
from Tamatave." |
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In
the beginning of 2012, a sapphire and ruby rush occurred |
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due
to the exceptional color, clarity and size of the precious |
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stones
found there. |
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Discovered
in alluvium, in the core of a wild forest, sapphires |
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and
rubies required holes from 50 centimeters to 2 meters |
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depth
only to be extracted. |
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Paper
written by the cutter. |
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| Alaotra
formations:
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| Crystalline
schists:
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| The
petrographic bottom is characterized by an abundance
of pyroxéno- |
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| amphibolic formations in a set in which
gneissico-migmatitic rocks are |
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| found as follows:
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| -
The gneisses at hypersthene are well represented on the
North and |
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| East bank of Lake Alaotra: |
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Amphibolites and shale feldspathics pyroxenites appearing
frequently in |
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| patches or enclaves to form
heterogeneous
migmatites of épibolites type |
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| (rocks
consist
of interbedded veins of aplites beds per bed).
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-
The amphibole gneiss, amphibole and biotite, or biotite alone
can pass |
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| locally to banded migmatites.
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Locally surmicaceous gneiss and mica becoming micaschists
and containing |
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| shreds of muscovite mica
schists
between the rivers Onibe and Ivondro.
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Finally, beds of quartzite or magnetite quartzite distributed
of very irregular |
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manner : magnetite quartzites show
a bigger development in the region of |
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| Imerimandroso
and Andilamena peninsula, on the shores of Lake
Alaotra; |
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| white quartzites more or less crystallized are quite
rare and form thin beds.
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| We
can distinguish an aluminous series and calco-magnesian
series. |
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| Alumino-silicate series is not uniformly
distributed, but appears quite clearly |
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| located at the
base of the group Alaotra. This series is represented by |
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sillimanite quartzites and gneisses more or less quartzic biotite,
sillimanite |
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| and garnet, very often these gneiss are graphitic.
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| Calc-magnesian
series develops on the western bank of the
group Alaotra, |
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| especially south of Ambatondrazaka where
diopside gneisses and marbles |
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| are of great importance.
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| - Gabros have a significant development in the group Alaotra,
their |
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main feature is their perfect match with the surrounding
formations. |
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©
All of the pictures on this
website have been shot by
gggems.com
|
Your
guide to GGGems |
 |
|
Text written by Alain Darbellay.
|
Alain
Darbellay |
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|
