Introduction: In our series of experiments to determine the noble gases of phase Q in various classes of meteorites [1,2] we analysed the HF/HCl-resistant residue of an enstatite chondrite [3]. We have chosen the EH5 chondrite St. Mark’s because of its short cosmic-ray exposure age (~1Ma [4]) which is essential to reliably determine the He-Q and Ne-Q isotopic composition. E-chondrites might hav...

A characterization study of chromite ore from South Africa was conducted using bulk assays, X-ray diffraction, optical, scanning electron microscopy (SEM), automated probe microanalysis (EPMA) and quantitative evaluation mineral by (QEMSCAN) mineralogical techniques, EPMA. The aim to identify all major gangue impurities, the degree liberation, possible beneficiation options. material assayed 40...

This work is designed to focus on the glassy network analysis and visualizing cluster subnets formation, rich set of bond-, edge- face-sharing linkages. The correlation between degree polymerization linkages forming apparently indicated. distribution SiOx clusters computed determine characteristic Mg-rich region. BOs, NBOs FOs also are investigated prove behavior Mg2+ incorporating into -Si-O- ...

Introduction: The presence and amount of Si in Earth's core has important implications for models of the processes and chemistry of core segregation. A metal core containing 5 to 7 wt. % Si can be produced when assuming continuous accretion and equili-bration along the silicate liquidus terminating at ~35 GPa and ~3,000 K, and with a concomitant increase in fO 2 from 4 to 2 log units below IW [...

Introduction: Presolar grains have been identified in primitive members of all chondrite classes [1,2]. The isotopic compositions of presolar grains provide probes of galactic evolution and nucleosynthesis in stars [3,4], while the abundances and characteristics of presolar grains contain a record of thermal processing in the solar system [2,5]. Most of the detailed isotopic work has been done ...