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Raman Spectra of Shocked Minerals 1: Olivine
Author(s) -
Heymann D.,
Cellucci T. A.
Publication year - 1988
Publication title -
meteoritics
Language(s) - English
Resource type - Journals
eISSN - 1945-5100
pISSN - 0026-1114
DOI - 10.1111/j.1945-5100.1988.tb00921.x
Subject(s) - olivine , raman spectroscopy , geology , mineralogy , spectral line , mineral , meteorite , analytical chemistry (journal) , materials science , chemistry , optics , physics , astrobiology , metallurgy , chromatography , astronomy
— The Raman spectrum of olivine contained in a chip of the Twin Sisters Peak dunite shocked to 22.2 GPa is essentially identical to the spectrum of unshocked olivine in this rock. The Raman spectra of a powder of the rock shocked to 20.1 GPa and of chips shocked to 59.5 GPa and 60.7 GPa show strong and broad low‐frequency features with crests at 475 cm −1 , 556 cm −1 , and 572 cm −1 , and strong as well as broad high‐frequency features near 1100 cm −1 . We conclude that these features are most likely due to the formation of “olivine glass” with a considerable degree of three‐dimensional Si‐O‐Si linkage, having scattered domains of greatly variable grain size, internal structure, and, possibly, chemical composition. We cannot conclude with our results at hand whether olivine shocked to the highest pressures has not decomposed to very fine‐grained MgO plus an SiO 2 ‐rich glass. We also conclude from our results that the structural changes are not likely to have formed in the laser beam of the measurement.