Structure–Composition Relationships for Mg–Ni and Mg–Fe Olivine

Olivine is a dynamic and important mineral in the crust and mantle with relevance to processes that are important to climate change technology, such as geologic carbon storage and critical mineral recovery. In this work, we critically evaluated and compiled a new database of olivine diffraction data, lattice parameters, and compositions to enable rapid Ni–Mg–Fe olivine composition determination. A compilation of olivine X-ray diffraction data and chemical compositions from both the literature and the International Centre for Diffraction Data (ICDD) powder database was assembled to plot both the forsterite–fayalite and forsterite–liebenbergite solid-solution lines. We present an expanded data set to delineate equations and relationships used for quantifying the correlations between olivine lattice parameters and chemical compositions in Mg2SiO4–Fe2SiO4 (forsterite–fayalite) and Mg2SiO4–Ni2SiO4 (forsterite–liebenbergite) olivine solid-solution series.