Activity-composition relation of jadeite in omphacite pyroxene: Theoretical deductions

Research output: Contribution to journalArticle

29 Scopus citations


Theoretical considerations suggest that the activity coefficient of jadeite in natural multicomponent omphacite pyroxene can be approximated by an expression of the form RT ln γjd {reversed tilde equals} W12 (XDi + XHed) (I - XJd), where W12 is an adjustable interchange parameter in the jadeite-diopside join, and X stands for the mole fraction of the specified component in the pyroxene solid solution. Synthesis of the available experimental and observational data yields W12 {reversed tilde equals} - 1400 (± 1400) + 1.16 (± 1.16) cal/mole, suggesting a nearly ideal solution around 1100°C, and negative departure from ideality at low temperature of the jadeite-diopside solid solution.

Original languageEnglish (US)
Pages (from-to)145-153
Number of pages9
JournalEarth and Planetary Science Letters
Issue number2
StatePublished - Jun 1973


ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science

Cite this