To understand the hydrosphere's internal cycle, we need to study the isotopic composition of hydrogen in the Earth's depths. We present a multidisciplinary approach to quantify the ratio of deuterium vs. hydrogen in nominally anhydrous minerals like olivine and its high-pressure polymorph wadsleyite. This study is a prerequisite for the determination of how heavy and light isotopes of hydrogen distribute among the different minerals hosting hydrogen in the mantle.

Ginelfite is a new Ag–Fe–Tl–Pb sulfosalt described from the hydrothermal deposit of Jas Roux (France). It belongs to the so-called boxwork sulfosalts, a group of species showing the highest structural complexity among this group of chalcogenides. This very complex structure is probably stabilized by the occurrence of minor chemical constituents (Tl, Fe) occupying specific structural positions.