INVESTIGATION OF STRUCTURE AND PHASE COMPOSITION OF THE CHELYABINSK METEORITE

Abstract

Six principal phases are found in the meteorite: three Fe – Ni solid solutions with different crystal lattices and nickel concentrations (α-kamacite with 3.5–5.5 at. % Ni, γ-taenite with 38–43 at. % Ni and ordered Fe – Ni phase with the cubic lattice), iron sulphides Fe_1-xS_x, olivine Mg_1,727Fe_0,273SiO₄ and aluminum silicates Al₂Si₂₄O₅₁. Metallic particles contain α and γ solid solutions separated by distinct interfaces. High-angle boundaries within both phases are not revealed. Unlike α and γ phases harder sulphides are present as aggregates of grains with well-defined high-angle boundaries.