Abstract
Sparingly soluble sulfate minerals, particularly barite (BaSO4), present an ideal system to understand mineral–water interfacial reactions. The model system barite has been used to develop crystal nucleation, growth, recrystallization, and pore-scale reactive transport models, both for the end-member cases, and in the presence of impurities that form isostructural solid solutions (Sr, Pb, Ra). Here, we present a comprehensive picture of the current body of research on sulfate minerals and their solid solution reactivity over spatiotemporal scales ranging from the molecular scale in picoseconds to the pore-scale in years of reaction time. Understanding reactivity of minerals at the pore-scale begins at the atomic-level where the structure of the mineral surface influences interfacial water structuring, and hence mineral reactivity. This review covers the inherently multiscale nature of mineral reactivity, ranging from atomic-scale interfacial structure to mesoscale impurity incorporation during recrystallization to pore-scale reactive transport models. In each topic, we identify gaps in knowledge, difficulties in cross-scale analyses, and future challenges in prediction of mineral growth, nucleation, and impurity transport across scales.
