The structure of (Ca,Co)CoSi2O6 pyroxenes and the Ca-M2+ substitution in (Ca,M2+)M2+Si2O6 pyroxenes (M2+ = Co, Fe, Mg)

  title={The structure of (Ca,Co)CoSi2O6 pyroxenes and the Ca-M2+ substitution in (Ca,M2+)M2+Si2O6 pyroxenes (M2+ = Co, Fe, Mg)},
  author={Luciana Mantovani and Mario Tribaudino and Francesco Mezzadri and Gianluca Calestani and Geoffrey David Bromiley},
  journal={American Mineralogist},
  pages={1241 - 1252}
Abstract The crystal structure of three C2/c clinopyroxenes with composition (Ca0.8Co0.2)CoSi2O6, (Ca0.6Co0.4) CoSi2O6 and (Ca0.4Co0.6)CoSi2O6 was refined down to R4σ = 2.6% by single-crystal X-ray diffraction. The crystals were synthesized at P = 3 GPa by cooling from 1500 to 1200 °C in a piston-cylinder apparatus. At the end of the refinement cycles, electron density residuals (up to 2.1 e-) were observed close to the M2 site and related to the site splitting of Ca and Co in the M2 polyhedron… Expand

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