Abstract
Omphacites are very important in petrology because of their occurrence in rocks metamorphosed under high-pressure conditions. They have a wide thermobaric range of stability. Raman spectra of a natural, iron-bearing, ordered omphacite have been studied and compared with the experimentally disordered spectra. The order-disorder phase transition causes extra modes in the spectra. The ordering state affects the full width at half maximum (FWHM) of the main omphacite peak at 680 cm_1. Ordered omphacite shows a split peak around 1010 cm_1 caused by the slightly different orientation of tetrahedra in the monoclinic chain.
Original language | English |
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Journal | Vibrational Spectroscopy |
Volume | 48 |
Pages (from-to) | 163-167 |
ISSN | 0924-2031 |
DOIs | |
Publication status | Published - 2008 |
Keywords
- Faculty of Science
- Raman
- Phase transition
- Pyroxenes
- Omphacite