 | Giuliani, Gaston, Groat, Lee, Fallick, Anthony, Pignatelli, Isabella, Pardieu, Vincent (2020) Ruby Deposits: A Review and Geological Classification. Minerals, 10 (7) 597 doi:10.3390/min10070597 | Journal (article/letter/editorial) | | of formation: (Type I) magmatic-related and (Type II) metamorphic-related.
Type I is characterized by...magmatic) origin are hosted by alkali basalts (Madagascar and
others), and Type IB corresponding to xenocrysts...in kimberlite (Democratic Republic of
Congo). Type II also has two sub-types; metamorphic deposits sensu...rubies from the
recently discovered Didy mine in Madagascar also command high prices [19]. A set of eight...Ambohimandrosoa,
Antsirabe area,
cm2.1
Ć 1.3
andcm
1.7Ćcm
1 cm
Ć 11.7cm)
Antsirabe area, Madagascar.
Collection: |  | Giuliani, Gaston, Fallick, Anthony, Rakotondrazafy, Michel, Ohnenstetter, Daniel, Andriamamonjy, Alfred, Ralantoarison, ThĆ©ogĆØne, Rakotosamizanany, Saholy, Razanatseheno, Marie, Offant, Yohann, Garnier, Virginie, Dunaigre, Christian, Schwarz, Dietmar, Mercier, Alain, Ratrimo, Voahangy, Ralison, Bruno (2007) Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin. Mineralium Deposita, 42 (3) 251-270 doi:10.1007/s00126-006-0105-3 | Journal (article/letter/editorial) | | isotope systematics of gem corundum deposits
in Madagascar: relevance for their geological origin
Gaston...dāAntananarivo,
Ambohitsaina, BP 906, Antananarivo 101, Madagascar
Y. Offant
Cerege, Europole MĆ©diterranĆ©en de lāArbois...Ambaranjana Antanimora,
Antananarivo 101, Madagascar
ces in Madagascar to provide a gemstone geological
identification...characterization. Primary corundum
deposits in Madagascar are hosted in magmatic (syenite
and alkali basalt)...xenoliths contained in the
alkali basalt of Soamiakatra have Ī“18O values ranging
between 1.3 and 4.7ā° |  | | Book | | and kimberlite (IB) hosts. Metamorphic
rocks (Type II) are subdivided into Metamorphic, sensu stricto,...Tanzania; Andilamena/Zahmena
and Ampanihy/Toliara, Madagascar. Marble-ruby types included various deposits...sapphire deposits included Andilamena and Andrebabe, Madagascar;
various Mogo Gem Tract sites, Myanmar; Elahera...Namehaca,
Mozambique and Ampanihy and Zahmena, Madagascar. In contrast, Appaluttoq ruby, Greenland,
4...of formation: (Type I) magmatic-related and (Type II) metamorphic-related.
Type I is characterized by |  | Garnier, V., Ohnenstetter, D., Giuliani, G., Fallick, A. E., Phan Trong, T., HoĆ ng Quang, V., Pham Van, L., Schwarz, D. (2005) Basalt petrology, zircon ages and sapphire genesis from Dak Nong, southern Vietnam. Mineralogical Magazine, 69 (1) 21-38 doi:10.1180/0026461056910233 | Journal (article/letter/editorial) | | erosional
deposits in southeast Asia, Australia and
Madagascar. The basalt Ā®elds yielding corundums
are widespread...deposits of
Dak Nong. The Dak Nong sapphire-mining
district lies in the Dak Lak Province near the
Cambodian...rocks sampled
from basaltic ĀÆows from the mining district of
Dak Nong. Chemical analyses for the samples...suite
Tholeiitic basalt suite
Subgroup I
Subgroup II
Sample
V75b
V75f
V75g
V75h
V75e
V74a
V74c...On the spider diagram (Fig. 5c,d),
the sub-group II is enriched in REE compared to
the sub-group I which |  | | Journal (article/letter/editorial) | | East African rift (Krzemnicki et al. 1996), in
Madagascar (Schwarz et al. 2000; Giuliani et al. 2007a)...rocks are alkali basalts and
basanites containing peridotite, pyroxenite, amphibolite,
and nepelinitite xenoliths...Thailand
(Sutthirat et al. 2001) or at Soamiakatra, Madagascar
(Rakotosamizanany 2003). Rubies are generally...area such as in Cambodia (Pailin), Madagascar
(Antanifotsy-Soamiakatra), Australia (Yarrowitch), and
Thailand...basalts is
found in central Madagascar (Rakotosamizanany 2003): the
Soamiakatra deposit in the Antanifotsy |  | | Report (issue) | | Yellowknife, Northwest Territories, 21-22 May, 2007. ii TABLE OF CONTENTS Preface 1. ix Diamond Thomas...Placer deposits in sedimentary fields: Ilakaka (Madagascar) SUMMARY ACKNOWLEDGEMENTS REFERENCES 3. EMERALD...Canada China Colombia Egypt India Kazakhstan Madagascar Mozambique Nigeria Norway Pakistan Russia South...("basaltic") kimberlite, as well as less common Group II ("micaceous") kimberlite (also named orangeite) and...evidence for a reduced character of deep cratonic peridotite (Woodland & Koch 2003, McCammon & Kopylova 2004 |  | Keulen, Nynke, Thomsen, Tonny B., Schumacher, John C., Poulsen, Majken D., Kalvig, Per, Vennemann, Torsten, Salimi, Rita (2020) Formation, origin and geographic typing of corundum (ruby and pink sapphire) from the FiskenƦsset complex, Greenland. Lithos, 366. 105536 doi:10.1016/j.lithos.2020.105536 | Journal (article/letter/editorial) | | e-
contact between ultramafic rock (typically peridotite or dunite), which commonly was hydrated prior...outcrops as a metasomatised reaction
zone between a peridotite and a leucogabbro, in which fluid interaction...Tanzania), the placer deposit of Andilamena (Madagascar), and to a lesser degree the metamorphic basaltic...ultramafic deposits like Winza, Tanzania and Ilalaka, Madagascar.
Pr
Again, this may reflect a similar history...ā worldwide only rubies from Madagascar (Andilamena, Ilakaka, Soamiakatra,
Iankaroka, Ambatomena) have |  | | Journal (article/letter/editorial) | | alkali basalt and
basanite ļ¬ows, some with mantle peridotite xenoliths, accompany
pyroclastic vents and dykes...blue
sapphires from non-basaltic ļ¬elds (Ilakaka, Madagascar; Ratnapura,
Sri Lanka; Mogok, Myanmar) to those...isotope
systematics of gem corundum deposits in Madagascar: relevance for their
geological origin. Mineralium..., 1994. Oxygen isotope composition of mantle
peridotite. Earth and Planetary Science Letters 128, 231ā241...alkali feldspar xenocrysts in basaltic terranes. II. Geochemical
and petrogenetic considerations. Canadian |  | | Book | | (Itabira), Colombia (Coscuez), Ethiopia (Shakisso), Madagascar (Mananjary),
Russia (Ural mountains), Zambia...I: muscovite, tourmaline, albite, and quartz; Zone II:
K-feldspar (microcline), quartz, and albite; Zone...medium-grained albite and quartz (Figure 3aāc); Zone II hosting homogeneous
medium-grained K-feldspar (microcline)...between Zones II and III (Figure 3e,f), and spodumene
and/or cassiterite in Zones I and II are common ([6]...microcline and quartz crystals collected from Zone II.
Muscovite grains gathered from Zone I were suitable |  | | Journal (issue) | | had to go on.
GEMS & GEMOLOGY
WINTER 2019
Madagascar are from metamorphic deposits, but the
deposits...basaltsātwo very different deposits, yet both from
Madagascar.
As stated earlier, when geographic origin determination...ring, courtesy
of Ronald Ringsrud; a
7.04 ct Madagascar sapphire, courtesy of Mayer
& Watt; and an exceptional...such as in Sri Lanka (Ratnapura, Elahera) and Madagascar (Ilakaka), produce the highest-quality sapphires...(Type I) and (2)
tectonic-metamorphic-related (Type II). Several subtypes are defined and especially Type |  | | Journal (article/letter/editorial) | | gypsum.
It is an ultramaļ¬c rock, a variety of peridotite consisting of the minerals, olivine and low-Ca...size of less than 1/16 mm (slate and mudstone).
Peridotite is a coarse-grained ultramaļ¬c igneous rock, consisting...Nephelinite
Norite
Novaculite
Okaite
Pegmatite
Pelite
Peridotite
Phonolite
Phoscretes
Phosphorite
CāD
A
A
E...aegirite and feldspar.
Websterite is a member of the peridotite family, containing both orthopyroxene and clinopyroxene...contents of Fe and Mg. Ultrabasic rocks (pyroxenite, peridotite, and
dunites) average 2000 ppm Cr, basic rocks | | | Journal (article/letter/editorial) | | gypsum.
It is an ultramaļ¬c rock, a variety of peridotite consisting of the minerals, olivine and low-Ca...size of less than 1/16 mm (slate and mudstone).
Peridotite is a coarse-grained ultramaļ¬c igneous rock, consisting...Nephelinite
Norite
Novaculite
Okaite
Pegmatite
Pelite
Peridotite
Phonolite
Phoscretes
Phosphorite
CāD
A
A
E...aegirite and feldspar.
Websterite is a member of the peridotite family, containing both orthopyroxene and clinopyroxene...contents of Fe and Mg. Ultrabasic rocks (pyroxenite, peridotite, and
dunites) average 2000 ppm Cr, basic rocks |
|