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.