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. 

The purpose of this paper is to present new perspectives on the pressure estimate of submicrometric white mica using energy-dispersive X-ray spectroscopy performed by a transmission electron microscope. This technique aims to explore the mineral chemistry of single grains whose dimensions do not allow for analysis by microprobe. The validation of this procedure opens a wide range of applications hitherto untested due to instrumental incompatibility with mineral phases smaller than 5 µm.

This paper reports a new natural oxyphosphate, the first mineral that crystallizes in the α-Fe₂PO₅ structure type. It is isotypic to a series of synthetic oxyphosphates with promising magnetic and electrochemical properties.