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A detailed Raman spectroscopic, electron microprobe, and laser ablation-induced coupled plasma-mass spectrometric study of 46 natural tourmalines [XY3Z6(T6O18)(BO3)3V3W] from 10 subgroups was performed to evaluate the potential of the Raman scattering, in particular of the OH bond stretching vibrations, for the identification of tourmaline species and site-occupancy analysis. The widespread chemical variety of the studied samples is reflected in the different spectral shapes. The positions and intensities of the observed vibrational modes can be used for tourmaline species identification. Taking into account the charge of the Y- and Z-site cations as well as the X-site occupancy, the Raman peaks generated by the bond stretching mode of the VOH groups were attributed to different YZZ-YZZ-YZZ cationic configurations, while the peaks originating from WOH stretching is due to chemically different YYY triplets next to an X-site vacancy, XNa, or XCa. It is shown that the integrated intensities of the VOH-stretching peaks can be used to calculate the contents of the major Y-site elements Mg, (Fe2++Mn2+), Li, and Al. The analysis of the VOH-peak positions yields information on the X-site occupancy. The fitted linear equations can be used to determine the content of X(Na+Ca) and X-site vacancy per formula unit. Guidelines for how to gain crystallochemical information from the Raman spectra of tourmaline are suggested. This study, along with Part 1 dedicated to amphiboles (Leissner et al. 2015), reveals that Raman spectroscopy is well suited as a non-destructive, preparation-free, and easy-to-handle method for species identification and site-occupancy analysis in complex hydrous silicate. Our results demonstrate that the chemistry on the non-tetrahedral positions substantially influences the Raman-active H-O bond stretching phonon modes, which allows for quantitative compositional analysis, including the content of lithium.

The crystal structure and chemical composition of a crystal of Mg-bearing phase Egg with a general formula M1-x3+Mx2+SiO4H1+x (M3+=Al, Cr; M2+=Mg, Fe), where x=35, produced by subsolidus reaction at 24 GPa and 1400°C of components of subducted oceanic slabs (peridotite, basalt, and sediment), was analyzed by electron microprobe and single-crystal X-ray diffraction. Neglecting the enlarged unit cell and the consequent expansion of the coordination polyhedra (as expected for Mg substitution for Al), the compound was found to be topologically identical to phase Egg, AlSiO3OH, space group P21/n, with lattice parameters a=7.2681(8), b=4.3723(5), c=7.1229(7) Å, β=99.123(8)°, V=223.49(4) Å3, and Z=4. Bond-valence considerations lead to hypothesize the presence of hydroxyl groups only, thereby excluding the presence of the molecular water that would be present in the hypothetical end-member MgSiO3·H2O. We thus demonstrate that phase Egg, considered as one of the main players in the water cycle of the mantle, can incorporate large amounts of Mg in its structure and that there exists a solid solution with a new hypothetical MgSiH2O4 end-member, according to the substitution Al3+⇌Mg2++H+. The new hypothetical MgSiH2O4 end-member would be a polymorph of phase H, a leading candidate for delivering significant water into the deepest part of the lower mantle.

Past studies have identified herbivory as a likely selection pressure for the evolution of hyperaccumulation, but few have tested the origin(s) of hyperaccumulation in a phylogenetic context. We focused on the evolutionary history of selenium (Se) hyperaccumulation in Stanleya (Brassicaceae). Multiple accessions were collected for all Stanleya taxa and two outgroup species. We sequenced four nuclear gene regions and performed a phylogenetic analysis. Ancestral reconstruction was used to predict the states for Se‐related traits in a parsimony framework. Furthermore, we tested the taxa for Se localization and speciation using X‐ray microprobe analyses. True hyperaccumulation was found in three taxa within the S. pinnata/bipinnata clade. Tolerance to hyperaccumulator Se concentrations was found in several taxa across the phylogeny, including the hyperaccumulators. X‐ray analysis revealed two distinct patterns of leaf Se localization across the genus: marginal and vascular. All taxa accumulated predominantly (65–96%) organic Se with the C–Se–C configuration. These results give insight into the evolution of Se hyperaccumulation in Stanleya and suggest that Se tolerance and the capacity to produce organic Se are likely prerequisites for Se hyperaccumulation in Stanleya.

We investigated emerald, the bright-green gem variety of beryl, from a new locality at Kruta Balka, Ukraine, and compare its chemical characteristics with those of emeralds from selected occurrences worldwide (Austria, Australia, Colombia, South Africa, Russia) to clarify the types and amounts of substitutions as well as the factors controlling such substitutions. For selected crystals, Be and Li were determined by secondary ion mass spectrometry, which showed that the generally assumed value of 3 Be atoms per formula unit (apfu) is valid; only some samples such as the emerald from Kruta Balka deviate from this value (2.944 Be apfu). An important substitution in emerald (expressed as an exchange vector with the additive component Al2Be3Si6O18) is (Mg,Fe2+)NaAl-1∎-1, leading to a hypothetical end-member NaAl(Mg,Fe2+)[Be3Si6O18] called femag-beryl with Na occupying a vacancy position (∎) in the structural channels of beryl. Based on both our results and data from the literature, emeralds worldwide can be characterized based on the amount of femag-substitution. Other minor substitutions in Li-bearing emerald include the exchange vectors LiNa2Al-1∎-2 and LiNaBe-1∎-1, where the former is unique to the Kruta Balka emeralds. Rarely, some Li can also be situated at a channel site, based on stoichiometric considerations. Both Cr- and V-distribution can be very heterogeneous in individual crystals, as shown in the samples from Kruta Balka, Madagascar, and Zimbabwe. Nevertheless, taking average values available for emerald occurrences, the Cr/(Cr+V) ratio (Cr#) in combination with the Mg/(Mg+Fe) ratio (Mg#) and the amount of femag-substitution allows emerald occurrences to be characterized. The \"ultramafic\" schist-type emeralds with high Cr# and Mg# come from occurrences where the Fe-Mg-Cr-V component is controlled by the presence of ultramafic meta-igneous rocks. Emeralds with highly variable Mg# come from \"sedimentary\" localities, where the Fe-Mg-Cr-V component is controlled by metamorphosed sediments such as black shales and carbonates. A \"transitional\" group has both metasediments and ultramafic rocks as country rocks. Most \"ultramafic\" schist type occurrences are characterized by a high amount of femag-component, whereas those from the \"sedimentary\" and \"transitional\" groups have low femag contents. Growth conditions derived from the zoning pattern-combined replacement, sector, and oscillatory zoning-in the Kruta Balka emeralds indicate disequilibrium growth from a fluid along with late-stage Na-infiltration. Inclusions in Kruta Balka emeralds (zircon with up to 11 wt% Hf, tourmaline, albite, Sc-bearing apatite) point to a pegmatitic origin.

Combustion as well as pyrolysis of tobacco greatly affect the type and levels of toxicants in cigarette smoke. We previously developed an approach to combine simultaneous temperature and pressure measurements with fast in-situ microprobe chemical sampling inside a burning cigarette, producing a series of temperature and gas-flow velocity maps that characterize this dynamic system in response to externally applied air flow.Two cigarette types differing only in diameter were puffed under ISO 3308 and Health Canada Intense (HCI) regimes to further understand the dynamic interaction of air flow and cigarette design parameters on tobacco combustion and pyrolysis by applying the thermophysical and thermo-chemical mapping approach.Three types of sampling probes were inserted, which are thermocouple arrays for gas-phase temperature, quartz tubes for pressure measurement, and a heated sampling microprobe coupled to a single-photon soft ionisation mass spectrometer for chemical analysis. Two kinds of similarly constructed cigarettes with the same blend were analysed: superslim (17 mm circumference) and king-size (24 mm circumference).Synchronization among the sampled signals was achieved by mapping two probes (e.g., temperature/chemistry or temperature/pressure) at a time. The physical and chemical events were visualised and compared between the cigarettes and puffing regimes.A series of temperature, pressure, and chemical maps were obtained for the superslim and king-size cigarettes under ISO and HCI conditions. The pressure in the burning cigarette was higher in the superslim cigarette, and the temperature distribution differed between the two cigarette formats. As expected, temperatures and pressures were higher under HCI puffing than under ISO puffing for both cigarette formats. Thermochemical maps for e.g., benzene and nitric oxide formation were qualitatively similar between the superslim and king-size cigarettes. For other substances the distribution was markedly different.The application of multi-probe in-situ chemical sampling is suitable to analyse highly dynamic combustion and pyrolysis processes occurring inside the two types of cigarettes. Ultimately, a direct comparison of cigarette circumferences on the complex combustion processes and formation of smoke constituents was achieved. [Beitr. Tabakforsch. Int. 29 (2020) 44–54]

Well-structured and adopting a pedagogical approach, this self-contained monograph covers the fundamentals of scanning probe microscopy, showing how to use the techniques for investigating physical and chemical properties on the nanoscale and how they can be used for a wide range of soft materials.

Rundqvistite-(Ce), ideally Na3(Sr3Ce)(Zn2Si8O24), is a new mineral from the Darai-Pioz alkaline massif, Tien-Shan Mountains, Tajikistan. The mineral occurs as elongated grains up to 0.1 mm long and up to 0.03 mm thick embedded in quartz–pectolite aggregate in a silexite-like peralkaline pegmatite. Associated minerals are quartz, fluorite, pectolite, baratovite, aegirine, leucosphenite, neptunite, reedmergnerite, orlovite, sokolovaite, mendeleevite-(Ce), odigitriaite, pekovite, zeravshanite, kirchhoffite and garmite. The mineral is colourless with a vitreous lustre and a white streak, brittle, Dmeas. is 3.70(2) and Dcalc. is 3.709 g/cm3. Rundqvistite-(Ce) is monoclinic, space group P21/c, a = 5.1934(16), b = 7.8934(16), c = 26.011(5) Å, β = 90.02(3)° and V = 1066.3(4) Å3. The chemical composition of rundqvistite-(Ce) is SiO2 40.17, La2O3 2.64, Ce2O3 7.55, Pr2O3 0.80, Nd2O3 2.43, Sm2O3 0.33, Eu2O3 0.09, Gd2O3 0.24, Tb2O3 0.18, Dy2O3 0.21, PbO 1.03, SrO 19.83, FeO 0.37, ZnO 13.08, CaO 2.55, Na2O 8.04, total 99.54 wt.%. The empirical formula calculated on 24 O apfu (atoms per formula unit) is Na3.10Sr2.29Ca0.54Pb0.06(Ce0.55La0.19Nd0.17Pr0.06Sm0.02Gd0.02Eu0.01Tb0.01Dy0.01)Σ1.04Zn1.92Fe0.06 Si8.00O24 Z = 2. The structural formula based on refined site-occupancies is (Na2.94Sr0.06)Σ3.00 [(Sr2.23Ca0.54Pb0.06Na0.13)Σ2.96Ln3+1.04]Σ4.00[(Zn1.92Fe2+0.06)Σ1.98Si8O24], where Ln3+1.04 = (Ce0.55La0.19Nd0.17Pr0.06Sm0.02Gd0.02Eu0.01Tb0.01Dy0.01)Σ1.04. The crystal structure of rundqvistite-(Ce) was refined to R1 = 2.76% on the basis of 3184 unique reflections [F > 4σ|F|]. In rundqvistite-(Ce), the main structural unit is a (Zn2Si8O24)12– sheet parallel to (100). In the sheet, the Si and Zn tetrahedra form four-, five- and eight-membered rings. The interstitial cations at the Na and M(1–3) sites sum to [Na3(Sr3Ce)]12– apfu. The Na and M(1–3) polyhedra share common edges to form a layer. Rundqvistite-(Ce) is a structural analogue of vladykinite, ideally Na3Sr4(Fe2+Fe3+)Si8O24. Rundqvistite-(Ce) and vladykinite are related by the following substitution: [8]Ce3+ + [4](Zn2+)2 ↔ [8]Sr2+ + [4](Fe2+Fe3+). The mineral is named after Dmitry Vasilievich Rundqvist (1930–2022), a prominent Russian geologist and an expert on the geology of ore deposits, metallogeny and mineralogy of Precambrian rocks.