Fe-carbide and Fe-sulfide liquid immiscibility in IAB meteorite, Campo del Cielo: Implications for iron meteorite chemistry and planetesimal core compositions

2013 ◽  
Vol 117 ◽  
pp. 80-98 ◽  
Author(s):  
Andrew G. Tomkins ◽  
Eleanor R. Mare ◽  
Massimo Raveggi
Keyword(s):  
Liquid Immiscibility ◽  
Iron Meteorite ◽  
Sulfide Liquid

scholarly journals Mineralogy of Silicate-Natrophosphate Immiscible Inclusion in Elga IIE Iron Meteorite

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 437
Author(s):  
Victor V. Sharygin
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Liquid Immiscibility ◽  
Iron Meteorite ◽  
New Mineral ◽  
Rare Type ◽  
Fine Grained ◽  
New Mineral Species ◽  
Silicate Inclusions ◽  
Dominant Phase

Rare type of silicate inclusions found in the Elga iron meteorite (group IIE) has a very specific mineral composition and shows silicate (≈90%)–natrophosphate (≈10%) liquid immiscibility due to meniscus-like isolation of Na-Ca-Mg-Fe phosphates. The 3 mm wide immiscible inclusion has been first studied in detail using optical microscopy, scanning electron microscopy, electron microprobe analysis and Raman spectroscopy. The silicate part of the inclusion contains fine-grained quartz-feldspar aggregate and mafic minerals. The relationships of feldspars indicate solid decay of initially homogenous K-Na-feldspar into albite and K-feldspar with decreasing of temperature. Some mafic minerals in the silicate part are exotic in composition: the dominant phase is an obertiite-subgroup oxyamphibole (amphibole supergroup), varying from ferri-obertiite NaNa2Mg3Fe3+Ti[Si8O22]O2 to hypothetical NaNa2Mg3Fe2+0.5Ti1.5[Si8O22]O2; minor phases are the aenigmatite-subgroup mineral (sapphirine supergroup) with composition close to median value of the Na2Fe2+5TiSi6O18O2-Na2Mg5TiSi6O18O2 join, orthopyroxene (enstatite), clinopyroxene of the diopside Ca(Mg,Fe)Si2O6–kosmochlor NaCrSi2O6-Na(Mg,Fe)0.5Ti0.5Si2O6 series and chromite. The alteration phases are represented by Fe-dominant chlorite, goethite and hydrated Na2O-rich (2.3–3.3 wt.%) Fe-phosphate close to vivianite. Natrophosphate part consists of aggregate of three orthophosphates (brianite, czochralskiite, marićite) and minor Na-Cr-Ti-clinopyroxene, pentlandite, rarely taenite. Czochralskiite Na4Ca3Mg(PO4)4 is rich in FeO (2.3–5.1 wt.%) and MnO (0.4–1.5 wt.%). Brianite Na2CaMg(PO4)2 contains FeO (3.0–4.3 wt.%) and MnO (0.3–0.7 wt.%) and marićite NaFe(PO4) bears MnO (5.5–6.2 wt.%), MgO (5.3–6.2 wt.%) and CaO (0.5–1.5 wt.%). The contact between immiscible parts is decorated by enstatite zone in the silicate part and diopside–kosmochlor clinopyroxene zone in the natrophosphate ones. The mineralogy of the studied immiscible inclusion outlines three potentially new mineral species, which were first identified in meteorites: obertiite–related oxyamphibole NaNa2Mg3Fe2+0.5Ti1.5[Si8O22]O2, Mg-analog of aenigmatite Na2Mg5TiSi6O18O2 and Na-Ti-rich clinopyroxene Na(Mg,Fe)0.5Ti0.5Si2O6.

scholarly journals Silicate-sulfide liquid immiscibility in modern arc basalt (Tolbachik volcano, Kamchatka): Part I. Occurrence and compositions of sulfide melts

2018 ◽  
Vol 478 ◽  
pp. 102-111 ◽  
Author(s):  
M. Zelenski ◽  
V.S. Kamenetsky ◽  
J.A. Mavrogenes ◽  
A.A. Gurenko ◽  
L.V. Danyushevsky
Keyword(s):  
Liquid Immiscibility ◽  
Sulfide Liquid ◽  
Tolbachik Volcano

scholarly journals Uakitite, VN, a New Mononitride Mineral from Uakit Iron Meteorite (IIAB)

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 150
Author(s):  
Victor V. Sharygin ◽  
German S. Ripp ◽  
Grigoriy A. Yakovlev ◽  
Yurii V. Seryotkin ◽  
Nikolai S. Karmanov ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Analytical Data ◽  
Structural Data ◽  
Iron Meteorite ◽  
Sulfide Liquid ◽  
Cubic Crystals ◽  
Reflected Light ◽  
Mohs Hardness ◽  
Ebsd Technique ◽  
Backscatter Diffraction

Uakitite was observed in small troilite–daubréelite (±schreibersite) inclusions (up to 100 µm) and in large troilite–daubréelite nodules (up to 1 cm) in Fe-Ni-metal (kamacite) of the Uakit iron meteorite (IIAB), Republic of Buryatia, Russia. Such associations in the Uakit meteorite seemed to form due to high-temperature (>1000 °C) separation of Fe-Cr-rich sulfide liquid from Fe-metal melt. Most inclusions represent alternation of layers of troilite and daubréelite, which may be a result of solid decay of an initial Fe-Cr-sulfide. These inclusions are partially resorbed and mainly located in fissures of the meteorite, which is now filled with magnetite, and rarely other secondary minerals. Phase relations indicate that uakitite is one of the early minerals in these associations. It forms isometric (cubic) crystals (in daubréelite) or rounded grains (in schreibersite). The size of uakitite grains is usually less than 5 μm. It is associated with sulfides (daubréelite, troilite, grokhovskyite), schreibersite and magnetite. Carlsbergite CrN, a more abundant nitride in the Uakit meteorite, was not found in any assemblages with uakitite. Physical and optical properties of uakitite are quite similar to synthetic VN: yellow and transparent phase with metallic luster; Mohs hardness: 9–10; light gray color with a pinky tint in reflected light; density (calc.) = 6.128 g/cm3. Uakitite is structurally related to the osbornite group minerals: carlsbergite CrN and osbornite TiN. Structural data were obtained for three uakitite crystals using the electron backscatter diffraction (EBSD) technique. Fitting of the EBSD patterns for a synthetic VN model (cubic, Fm-3m, a = 4.1328(3) Å; V = 70.588(9) Å3; Z = 4) resulted in the parameter MAD = 0.14–0.37° (best-good fit). Analytical data for uakitite (n = 54, in wt. %) are: V, 71.33; Cr, 5.58; Fe, 1.56; N, 21.41; Ti, below detection limit (<0.005). The empirical formula (V0.91Cr0.07Fe0.02)1.00N1.00 indicates that chromium incorporates in the structure according to the scheme V3+ → Cr3+ (up to 7 mol. % of the carlsbergite end-member).

Silicate-sulfide liquid immiscibility in modern arc basalt (Tolbachik volcano, Kamchatka): Part II. Composition, liquidus assemblage and fractionation of the silicate melt

2017 ◽  
Vol 471 ◽  
pp. 92-110 ◽  
Author(s):  
Vadim S. Kamenetsky ◽  
Michael Zelenski ◽  
Andrey Gurenko ◽  
Maxim Portnyagin ◽  
Kathy Ehrig ◽  
...  
Keyword(s):  
Liquid Immiscibility ◽  
Silicate Melt ◽  
Sulfide Liquid ◽  
Tolbachik Volcano

scholarly journals Reprint of Silicate-sulfide liquid immiscibility in modern arc basalt (Tolbachik volcano, Kamchatka): Part II. Composition, liquidus assemblage and fractionation of the silicate melt

2018 ◽  
Vol 478 ◽  
pp. 112-130 ◽  
Author(s):  
Vadim S. Kamenetsky ◽  
Michael Zelenski ◽  
Andrey Gurenko ◽  
Maxim Portnyagin ◽  
Kathy Ehrig ◽  
...  
Keyword(s):  
Liquid Immiscibility ◽  
Silicate Melt ◽  
Sulfide Liquid ◽  
Tolbachik Volcano

Microstructural Analysis of SiO2-Al2O3 Glasses

1982 ◽  
Vol 40 ◽  
pp. 562-563
Author(s):  
C. M. Jantzen ◽  
D. G. Howitt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microstructural Analysis ◽  
Liquid Immiscibility ◽  
Metastable Region ◽  
Transmission Electron ◽  
Liquidus Temperatures

The mullite-SiO2 liquidus has been extensively studied, and it has been shown that the flattening of the liquidus is related to the existence of a metastable region of liquid immiscibility at sub-liquidus temperatures which is detectable by transmission electron microscopy (TEM) (Fig. 1).

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