Thermoelastic Properties of Fayalite at High Temperatures and High Pressures
Year: 2026
Type: article
Abstract: Fayalite (Fe2SiO4), the Fe-rich end-member of the olivine solid-solution series, is a key mineral in governing the thermodynamic behavior of Fe-rich planetary mantles. Here, using an iterative numerical approach constrained by previous experimental data, we extracted the volume, elastic properties, and, most importantly, the thermodynamic properties, including thermal expansion, isobaric heat capacity, entropy, and the Grüneisen parameter of fayalite up to 20 GPa and 2000 K. Our results demonstrate that all these thermodynamic properties are positively correlated with temperature but negatively correlated with pressure. Also, thermal expansion, isobaric heat capacity, entropy, and the Grüneisen parameter of fayalite are generally higher than those of San Carlos olivine, but show lower pressure dependence. This work provides a comprehensive thermodynamic dataset for modelling phase equilibria in the Fe–Mg olivine system and for refining interpretations of the thermal state of iron-rich planetary mantles.
Source: Geosciences
Authors: Chang Su, Xiaoqing Xu, Wei Song, Yonggang Liu
Institutions: Chinese Academy of Sciences, Institute of Geochemistry
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,172
OpenAlex ID: W7225786909