Geochemistry data for vaterite partition coefficients and comparison with foraminiferal values

This dataset serves as the electronic supplementary material for the manuscript “Multi-element partitioning into nanocrystalline vaterite and implications for foraminiferal vital effects”. We hypothesize that trace element incorporation into vaterite is fundamentally distinct from calcite due to vaterite's metastable, nanocrystalline nature. Specifically, we predict that divalent cations (Mg, Sr, Ba) will exhibit size-dependent partitioning controlled by lattice-strain energetics, while monovalent cations (Li, Na) will show strong kinetic enrichment due to surface adsorption and dynamic hydration layer effects. Synthetic vaterite was precipitated under controlled conditions across 5–30 °C and Mg/Ca = 0–0.2. Initial and final solution concentrations of Li, Na, Sr, Ba, Mg, and Ca were measured, and solids were analyzed for elemental composition. Theoretical growth rates were calculated from Ca depletion over time. The dataset contains complete elemental geochemistry from vaterite experiments, including experimental conditions (temperature, pH, Mg/Ca, growth rate), initial and final solution concentrations, solid-phase elemental ratios (element/Ca), and calculated partition coefficients. It also compiles literature partition coefficients for comparison, including foraminifera, calcite, aragonite, and amorphous calcium carbonate (ACC), along with standard reference material measurements for quality control.