Madagascar gem safari

Written by Alain Darbellay GGGems

© 2004 All rights reserved. MADAGASCAR GEM SAFARI 2 Sapphire from Maromby in a metamorphic limestone. ( Andranondambo area.) Looking for sapphire onrepparttar ground in 1992. Sapphires from Andranondambo, discovered in 1991. ( South-East of Madagascar ) In 1658, Flacourt,repparttar 109300 governor of Fort-Dauphin mentions sapphires inrepparttar 109301 south of Madagascar. In 1808, Barthélemy Hugon writes that inrepparttar 109302 valley of Ambolo there is a so beautiful stone and so rare that lapidaries have not been able to recognize it and it was above of all that is not diamond. ... In 1991, atrepparttar 109303 time of repparttar 109304 great dryness inrepparttar 109305 south, sapphire samples are found, several centuries after their first discovery. The son of Mrs. Dauphine, innkeeper in Tranomaro, main village ofrepparttar 109306 valley, was amongrepparttar 109307 prospectors. Actually, one ofrepparttar 109308 most beautiful quality inrepparttar 109309 world is just leaving ground. The area of Tranomaro is characterized by an extreme calcic and magnesian paragneiss abundance: gneiss with diopside, plagioclasites, pyroxenites, wernerites, wolastonite limestones, with varied leptynites, generally with garnet, kinzigites, quarzites. One finds there rather frequently syenitic gneisses or lamboanites. Gneisses of injection are very frequent. The typomorphic minerals are: basic diopside, scapolite, calcite, plagioclases, wollastonite, garnet, cordierite and corundum. East of Tranomaro, arteritic and eyesys injections assign gneisses at leptynites. Cordierite gneiss bands are deeply injected bed by bed,repparttar 109310 injection has introduced magnetite in abundance. Wollastonites form ptymatic lenses with Marohotro, 18 km. south from Andanondambo. folds very tortured atrepparttar 109311 middle ofrepparttar 109312 limestone. Note: The sapphire onrepparttar 109313 left comes from Ambandanira, and aluminous anorthites or sakenites. that on right-hand side from Maromby (area of Andranondambo) Sapphire from Behataza plateau (Andranondambo area) Sapphires from Ilakaka. One ofrepparttar 109314 various holes in sandstone forming ( South-West of Madagascar )repparttar 109315 deposit of Ilakaka discovered in to 1998. Blue sapphires , pink and violet, Ilakaka area. SANDSTONES OF ISALO. The white sandstones of Isalo present imposing stratifications intersected with gravel beds and small conglomerates. These soft sandstones resisted to erosion and taken a ruiniform relief becauserepparttar 109316 presence of braces siliceous veins. The mineral-bearing deposits include : a deposit of generally classified gravels,repparttar 109317 richest part and larger elements being atrepparttar 109318 base ofrepparttar 109319 bed - rock. MORE ABOUT ILAKAKA

Andranondambo Sapphire discovery ( Madagascar )

Written by Alain Darbellay GGGems

© 2004 All rights reserved.

Tranomaro in 1991 >> Geographical division We will distinguish: 1repparttar volcanic solid mass of Androy, it is covered with thorny bush and meadows. 2repparttar 109299 gneissic zone of to Mandrarean Androy, fields plains and hills, rare zones of savanna on of red ground Atrepparttar 109300 time calcareous carapace. ofrepparttar 109301 great Altitude varies there from dryness in 600 meters onrepparttar 109302 hillsrepparttar 109303 south. to 250 meters atrepparttar 109304 bottom. 3repparttar 109305 western slope ofrepparttar 109306 high Anosyans chains which tops are staged between 1500 and 2000 meters. It is a field of meadows. Geological divisions. 1 Crystalline schists. Gneiss with diopside, syenitic eysies gneisses, arteritic injections, gneiss at cordierite, etc. 2 Old eruptive rocks. Pegmatites, Dissogénites, Esirians granites , charnockites, kalambatreans granites, late granites . 3 Recent eruptive rocks. (Volcanic solid mass of Androy) a) Arepparttar 109307 base, a thick basaltic subhorizontale series . b) Basaltic dykes. Onrepparttar 109308 road to Andranondambo c) A thick higher subhorizontale rhyolitic series. d) Rhyolitic dykes . 4 Recent formations. If russet-red sands are excluded,repparttar 109309 recent

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