Recent  

The paper documents sillimanite gneiss in the Western Gneiss Region (WGR) and its presence, composition, formation and metamorphic evolution. Peak metamorphism is modelled to T = 750 °C and P around 0.6 GPa. Subsequent retrogression consumes garnet and shows mineral replacement and melt crystallization involving sillimanite, white mica, K-feldspar and quartz. The petrological evolution is in accordance with the investigated eclogites and HP granulites in the northwestern part of WGR.

The manganese-rich siliceous metasediment in the Antarctic Ross orogen most likely originated from Mn-nodule-bearing chert deposited not earlier than ca. 546 Ma. Subduction-related metamorphism resulted in the production of highly oxidized assemblages involving Mn³⁺ and rare-earth-element-zoned epidote-group mineral and Mn²⁺-rich garnet. A reduced environment was responsible for the Mn olivine-bearing assemblages from silica-deficient composition.

We described two new minerals, igelströmite and manganoschafarzikite, from the Långban manganese–iron deposit in Värmland, Sweden. The chemical formulae are Fe³⁺(Sb³⁺Pb²⁺)O₄ and  Mn²⁺Sb³⁺₂O₄, respectively. They belong to a new mineral group, where all members have the same crystal structure. It is called the minium group, after the lead-oxide mineral that is the oldest known substance of this kind.

The first lanthanum-dominant mckelveyite group mineral, alicewilsonite-(YLa), Na₂Sr₂YLa(CO₃)₆∙3H₂O, was found at the Paratoo copper mine, South Australia, Australia.

We studied primary granitic and halogen-rich melt inclusions trapped in mantle rocks in the Bohemian Massif (Germany) in order to retrieve important information about the nature of the melt and the source rock. The melt was produced by the partial melting of metasediments during the deepest stages of subduction and interacted with the mantle. This work is an excellent example of transfer of crustal material, volatiles in particular, in the mantle during the subduction of the continental crust.

Macraeite is the fourth type mineral to be described from the Mangualde pegmatite, Portugal, and is the first paulkerrite-group mineral to be characterised from the locality. Its crystal structure has been refined using synchrotron diffraction data, and its chemical analysis, Raman spectrum, and optical properties are reported.

To explore the compositional constraints on Cl incorporation into amphiboles, which can be used to characterize transient brines, amphiboles were synthesized with a broad range of Cl concentrations. Amphibole Cl was found to be dependent on the Fe^2+,3+ content, but not the tetrahedral Al content or K / Na ratio. Cl incorporation was found to contract the unit cell along a and expand it along b and c. Molar volumes were derived for endmember Cl-amphiboles using multivariate regressions.

Models for the generation of silicic magmas are divided into two groups: intra-crustal melting and basaltic origin. Peraluminous felsic leucogranites are considered as the only granite examples showing no mantle input. This interpretation is re-evaluated, and we show that leucogranites, as most other crustal granite types, can have a mantle filiation. This stresses the critical importance of the mantle for granite generation and opens the way for unification of silicic magma generation models.

The acid igneous rocks of eastern Croatia related to the Late Cretaceous closure of the Neotethys Ocean contain zircon as a main accessory mineral. Among others, zircon has inclusions of anatase, hematite and melt (nanogranitoids) with kokchetavite and kumdykolite. The first finding here of kokchetavite and kumdykolite in a magmatic nanogranitoid proves that these are not exclusively ultra-high pressure phases. The detected inclusions indicate rapid uplift and cooling of the oxidised magma.

The new spectroscopic method, based on the syncrotron radiation, allows for determination of Fe oxidation state in tiny objects or in heterogeneous samples. This technique is expected to be an important tool in geosciences unraveling redox conditions in rocks and magmas as well as in material sciences providing constraints on material properties.

The new mckelveyite group mineral bainbridgeite-(YCe) was found at Mont Saint-Hilaire, Quebec, Canada.

Boron is a common additive in industrial glasses used for a wide variety of applications and in experimental degassing studies regarding exoplanet atmospheres. It is therefore important to constrain the behavior of this component in the melt phase. For this reason we investigated experimentally the evaporation of B₂O₃ from Ca- and Mg-bearing aluminoborosilicate melts at different temperatures, as a function of time and oxygen fugacity.

The new mineral heimite was originally discovered on the mine dumps of the Grosses Chalttal deposit, Mürtschenalp district, Glarus, Switzerland. Its relatively simple chemistry is formed by water and ions of lead, copper, arsenic, hydrogen and oxygen. The mineral's crystal structure is related to the well-known duftite, which is also observed to grow on crystals of heimite. While heimite has so far only been found in the central Alps, it is expected to occur in other copper deposits worldwide.

This is the first successful synthesis of jadarite, a Li–B ore mineral. Synthetic jadarite was characterized by powder X-ray diffraction, Fourier transform infrared, Raman, and Li and B K-edge X-ray absorption near-edge structure. The results are evaluated by first-principles theoretical calculations. Our findings for jadarite in sediments derived from Li-rich alkaline brines under high-temperature diagenetic conditions have implications in the search for new Li–B deposits in sedimentary basins.

I review investigations of melt inclusions in lunar rocks in the last 53 years. They can be divided into two stages. In the first stage (1970s), melt inclusion studies focused on major oxides and magma evolution, including the discovery of silicate liquid immiscibility. In the second stage (since 2010), melt inclusion studies have provided key constraints on water and other volatiles on the Moon and have been instrumental in the paradigm shift from a “bone-dry” Moon to a fairly wet Moon.

Petrological and mineralogical studies of mica schists, orthogneisses and glaucophane eclogites from Dumet Island (Armorican Massif, NW France) indicate that this occurrence, which has undergone high-pressure metamorphism up to 16 kbar and 620 °C, is similar to that of Groix Island. There are about 10 similar occurrences within the Ibero-Armorican Arc, forming a discontinuous high-pressure belt, but most of them have remained unnoticed due to a high degree of retrogression.

The paper proposes an application called OxyEMG (Oxyspinel group End-Member Generator), which is an improved version of EMG. This tool allows for calculating the portions of 31 end-members of the oxyspinel group from data obtained with an electron microprobe. This is fundamental since this group of minerals is considered to be tectonic tracers; their integral composition should be taken into account and not only those end-members that make up the magnetite or ulvöspinel prisms.

We report the description and the characterization of a new mineral species, found in a rock sample from the geological formation called the Pilanesberg Complex, South Africa. This is a silicate mineral that contains a significant amount of sodium, calcium, iron, titanium and fluorine. Its atomic structure shows that it is related to other wöhlerite-group minerals. This work provides new insights into the crystallization conditions that ruled the formation of the Pilanesberg complex.

X-ray absorption spectroscopy (XAS) was successfully used to investigate the atomic-scale environment of niobium (Nb) in ore minerals and Nb-doped compounds of technological importance. The demonstrated sensitivity of this technique to Nb minerals could help decipher Nb speciation in mining contexts such as hydrothermal and lateritic deposits and rationalize the origin of the enhanced physico-chemical properties of Nb-doped materials.

Minerals formed by weathering of toxic materials, of either natural or human origin, act as storage containers for toxic elements. In this work, we investigated properties of common minerals which store and release arsenic in the environment. The data presented here will allow for improved modeling of the polluted sites and for better remediation strategies that could be applied to minimize the impact of the pollution on the environment.

We investigate the occurrence, texture, composition, and chronology of three types of zirconolite in dolomite marbles from the Mogok metamorphic belt, Myanmar. These zirconolites, which were formed by multiple episodes of fluid–marble interaction, record the time-resolved fluid infiltration history in metacarbonates and reactive fluid compositions from ~35 to ~19 Ma. Zirconolite is expected to play a more important role in orogenic CO₂ release and the transfer and deposition of rare metals.

In this work, we refine the crystal structure of childrenite. Additionally, we provide compositional data to substantially extend the published solid-solution series between childrenite and eosphorite, the Fe and Mn endmembers, respectively. We analyze the valence state of iron to avoid erroneous classification of ernstite or potential discovery of "oxychildrenite", a mineral species not yet confirmed to be stable in nature.