Batoniite is a new mineral species belonging to the Al₂O₃–SO₃–H₂O ternary system, first found in the Cetine di Cotorniano Mine (Tuscany, Italy). This hydrated Al sulfate shows a novel crystal structure, characterized by Al octamers, so far reported in only synthetic compounds.

We investigate rocks called eclogite, which are related to subduction and the collision of continents. Our samples show evidence of limited melting at high pressure corresponding to about 70 km depth, which may play an important role in the exhumation of these rocks and the differentiation of the crust. However, due to their composition and metamorphic evolution, melt production is limited, suggesting that similar rocks are unlikely to contribute strongly to subduction-related magmatism.

Since As is detrimental to the environment, the As content of ores should be reduced before it is released into the atmosphere through a smelting process. Thus, Raman spectra of typical As minerals were investigated, and these can be used in the industrial removal of As-rich ores prior to the ore beneficiation. An additional objective of our study was an investigation of the secondary products of enargite weathering. They play a decisive role in the release or retainment of As in the waste form.

Elba tourmaline crystals commonly display a sharp transition to dark colors at the analogous termination, but the mechanisms leading to the formation of such terminations are unclear. Here we propose a general genetic model in which, as a consequence of a pocket rupture event, chemical alteration of early formed Fe-/Mn-rich minerals in the enclosing pegmatite was responsible for the release of Fe and/or Mn in the geochemical system, allowing the formation of the late-stage dark terminations.

This paper reports on metamorphic titanate + zircon pseudomorphs after igneous zirconolite based on the textural relationships in samples from a key locality of a Mesoproterozoic syenodiorite, in which the rock preserves different states of deformation and metamorphic recrystallisation. The metamorphic reaction to form titanite + zircon intergrowths required the zirconolite breakdown and the release of silica and calcium from the consumption of igneous pyroxene and feldspars.

We calibrate new models for the properties of solid and liquid FePt alloy. FePt alloy is used in experiments investigating the origin, differentiation, and evolution of planets to characterize oxygen fugacity. The new models facilitate use of FePt for more extreme conditions than has been possible previously. We also describe shortcomings in the present knowledge of FePt alloy properties and highlight strategies that could improve such knowledge.

Regerite is the first new mineral species to be described from the Kreuzberg pegmatite, Pleystein, in the Oberpfalz, Bavaria. It has been characterised using electron microprobe analysis, Raman spectroscopy, optical measurements and a synchrotron-based single-crystal structure refinement. The structure type for regerite has not been previously reported.

This study presents a new method designed to analyze micrometer-scale chemical and isotopic profiles in minerals, glasses, and other solids. The employed technique combines plasma mass spectrometers and a state-of-the-art femtosecond laser equipped with open-source software (LinuxCNC) that controls the movement of the laser beam. It allows for equably drilling into the sample surface, e.g., in order to measure chemically or isotopically zoned or heterogeneous materials at micrometer scales.

Minerals in a vein network from the Aravis limestone (Haute-Savoie, France) include carbonates, quartz, fluorite and phyllosilicates, crystallized at around 7 km depth and 190 °C. The mineralogy has been studied with emphasis on the chlorite types: chamosite (iron-rich), cookeite (lithium-rich) and sudoite. The presence of the three chlorite types sheds light on their phase diagrams, and observed cationic substitutions confirm the need for more systematic measurement of lithium in chlorite.

Two examples of granites in the Variscan Iberian Massif were studied because they are associated with mafic rocks (appinites and vaugnerites), which raise the question of the role of mantle magma in the formation of granitic rocks. We conclude that appinites and vaugnerites derived from melting of different mantle sources, both previously modified by interaction with crustal materials. Subsequent differentiation of appinites and vaugnerites was influenced by contamination with coeval granites.

The infrared spectrum of hydrous defects in corundum is routinely used in gemology, but the assignment of absorption bands to specific defects remains elusive. Here, we theoretically study selected defects and compare the results with available experimental data. The main results are the assignment of the 3161 cm⁻¹ series to OH groups associated with Fe²⁺ ions and the interpretation of bands below 2700 cm⁻¹ in corundum containing divalent cations in terms of overtones of OH bending modes.