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Your search keyword '"C2/c Pyroxenes"' showing total 2 results
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2 results on '"C2/c Pyroxenes"'

1. Relationships between tetrahedral kink angles and site occupations in C2/c pyroxene from volcanic rocks

Author

L. Secco, Francesco Princivalle, Gabriella Salviulo, Secco, L, Salviulo, G, and Princivalle, Francesco

Subjects
geography, C2/c pyroxene, geography.geographical_feature_category, kink-angle, Geochemistry, Pyroxene, T tetrahedral chain, Volcanic rock, Geophysics, Geochemistry and Petrology, kink angke, site occupation, Tetrahedron, C2/c pyroxenes, site occupations, volcanic rocks, Geology
Abstract

The relationships between kinking of the T tetrahedral chain and the site configuration of C2/c pyroxenes from volcanic rocks were investigated, and about two hundred samples were examinated.

Published
1995

2. Effects of Ca-Mg Substitution in C2/c pyroxene structure on natural clinopyroxenes from spinel peridotite nodules (Pico Cabugi, Brazil)

Author

C. Fabro, Francesco Princivalle, G. Demarchi, Gabriella Salviulo, G., Salviulo, Princivalle, Francesco, Demarchi, Gabriella, and C., Fabro

Subjects
Nodule (geology), Microprobe, C2/c Pyroxene, C2/c Pyroxenes, Mineralogy, Pyroxene, Crystal structure, engineering.material, Geochemistry and Petrology, CRYSTAL-STRUCTURE REFINEMENT, General Materials Science, Ca-Mg substitution, Mg-Ca substitution, spinel peridotites, Brazil, Peridotite, clinopyroxenes, Materials processing, Chemistry, Spinel, spinel peridotite, Crystallography, engineering
Abstract

X-ray crystal structure refinements and microprobe analyses of clinopyroxenes from two suites of spinel-peridotite nodules are compared for an understanding of the structural response to a decrease in Ca content. The kinking of the tetrahedral chain (O3-O3-O3 angle) of the C2/c structure associated with decreased Ca content shows behavior similar to that observed for the A-tetrahedral chain of the P21/c structure. Contemporaneously the occupancy of the M2′ split site increases. In addition, as a consequence of the low Ca content, the M2 polyhedron dominates the structural rearrangement of the clinopyroxenes considered here.

Published
1992

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