Interactions between minerals and water are fundamental to many geological processes on Earth, in meteorites, and on other planetary bodies, for instance, in the development of plate tectonics. In this study, we experimentally determine how quickly hydrogen isotopes are exchanged between minerals and fluids. We then explore how exchange rates can inform us about past interactions between rocks and water on the Earth and in meteorites using hydrogen isotope measurements in natural minerals.

Natural ruby and sapphire are of the rarest gemstones. To further enable their identification from synthetic analogues, this study explores secondary ionization mass spectrometry (SIMS) oxygen isotope analysis. SIMS δ¹⁸O analysis of hydrothermal corundum yielded values between -7.84 ± 0.13 ‰ and -14.54 ± 0.13 ‰ (Vienna Standard Mean Ocean Water), which are atypical for natural corundum. SIMS δ¹⁸O analysis of corundum thus has strong potential to distinguish synthetic and natural corundum.

Iron sulfides are ubiquitous minerals of sedimentary environments. Several research works consider it to be that they preserve evidence of their original deposition environment, allowing us to derive paleo-environmental information. However, linking environmental factors to final mineralogy requires gaining mechanistic-level information about their formation pathways. Here, we propose a mackinawite to greigite "corrosion" pathway, with H+ acting as an oxidant.