Megawite, a recently discovered perovskite-structured mineral with Ca(Ti_0.07, Sn_0.6, Zr_0.33)O₃, was identified in a xenolith. Its end members, CaTiO₃, CaSnO₃, and CaZrO₃, represent GdFeO₃-type perovskites (A²⁺B⁴⁺O3), which have garnered significant attention for their structural and physical properties. Among these, CaSnO₃ stands out due to its exceptional optical and electrical properties, supported by its high physical and chemical stability. Despite its increasing applications, critical physical properties such as the elastic moduli (Cij) of single-crystal CaSnO₃ have yet to be determined experimentally. Available data on CaSnO₃ elasticity stems from polycrystalline measurements or computational predictions. This gap underscores the need for experimental determination of single-crystal elastic moduli better to understand its mechanical behavior and implications for future applications.

Here, we report the elastic moduli of single-crystal CaSnO₃ perovskite measured using Brillouin scattering at ambient conditions. Crystals of CaSnO₃ were synthesized at 1200 °C over 24 hours from a starting mixture of CaCl₂ and SnO₂ in a 2:1 molar ratio. Four high-quality crystals were selected for Brillouin scattering measurements. Full elastic moduli were derived via least squares regression of sound velocity data against the Christoffel equation. The obtained values for the elastic moduli include longitudinal moduli (C₁₁, C₂₂, C₃₃) ranging from 270 to 290 GPa, shear moduli (C₄₄, C₅₅, C₆₆) between 90 and 98 GPa, and off-diagonal moduli (C₁₂, C₁₃, C₂₃) ranging from 100 to 120 GPa. These measurements' aggregate bulk modulus, shear modulus, and sound velocities align well with previous polycrystalline results obtained through ultrasonic interferometry (Kung et al., 2001; Schneider et al., 2008).

A key step in Brillouin scattering data analysis is the establishment of an initial Cij model. For a new material such as CaSnO₃, setting up an effective starting model requires experience. In this study, the starting Cij model was derived from density functional theory (DFT) computations to serve the purpose. Elasticity and electronic ground states were calculated using the CASTEP code integrated within the Materials Studio software package. These calculations employed LDA, GGA, and mGGA functionals, with norm-conserving and ultrasoft pseudopotentials modeling electron-ion interactions. The computationally predicted Cij values served as the initial input for data fitting. The final best-fit Cij model was determined by minimizing residual differences across iterative fitting steps. The close agreement between experimental and computational results highlights the utility of computational predictions as a starting point for Brillouin scattering analyses.

This study presents the first experimental determination of the elastic moduli for single-crystal CaSnO₃ perovskite, supported by computational insights. The integration of experimental and computational approaches offers a robust framework for characterizing the mechanical properties of new materials. Our findings contribute to the broader understanding of perovskite materials, with implications for geosciences and advanced material applications.

How to cite: Kung, J., Hua, F. T. S., Su, W., and Zhang, J.: Elastic Moduli of Single-Crystal CaSnO3 Perovskite, end-member of Megawite: Bridging Experimental and Computational Approaches, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5577, https://doi.org/10.5194/egusphere-egu25-5577, 2025.

The present study examines the effect of metamorphism on point defects in quartz. A granite sample with crystallization age of ~460 Ma (Albesti granite, Romania) and its metamorphic equivalent were used for the analysis. This sill-like granitoid occurs close to a ductile shear zone (locally named Bughea shear zone) of presumed Variscan age; the granitoid is exposed as relatively undeformed away from the shear zone as well as highly strained into a mylonitic fabric, when caught into the shear zone. Mineralogical differences were also observed, the metamorphic sample exhibiting lower quartz content and reduced grain strength. The point defects in quartz were characterized using thermoluminescence (TL), optically stimulated luminescence (OSL), electron spin resonance (ESR), scanning electron microscopy coupled with cathodoluminescence (SEM-CL) and Raman spectroscopy.

ESR data showed the presence of E’ (an unpaired electron at an oxygen vacancy site (≡Si·), Al-related defects ([AlO₄]⁰) and peroxy (≡Si-O-O·) in both the samples with increase of these centres in the metamorphic sample, especially in the case of the latter. TL measurements showed four peaks (110, 160, 280, 380 °C) in both samples, though TL intensity was 40% lower in the metamorphic quartz. The OSL decay curves were dominated by fast component for un-deformed sample and the OSL intensity of the metamorphic quartz was approximately 60% lower than that of un-deformed granite. The OSL dose-response curve (DRC) is well represented by a sum of two saturating exponential functions. The DRC of metamorphic granite exhibited higher uncertainties, due to its low signal. The DRC shapes before and after heating were nearly identical for both samples. SEM-CL analysis showed emission in blue (~450 nm) and red region (~650 nm; attributed to NBOHC (≡Si–O·)). The CL emission of metamorphic quartz was 65% lower than that of un-deformed quartz. Raman spectroscopy showed narrowing of quartz bands in the region of 100 to 500 cm^⁻¹, reflecting the shortening of the O-Si-O bond (463 cm^⁻¹) and lattice compression (125 and 204 cm^⁻¹) during metamorphism. The increase at the 1030 cm^⁻¹ peaks indicates the high aluminium-to-silicon ratio which concords with the ESR measurements.

These findings provide new insights into mineralogy and quartz point defect dynamics under metamorphic conditions, with implications for geological processes. At the conference, detailed results and their implications will be presented.

Acknowledgement: This research is funded by European Research Council ERC grant PROGRESS-CoG “Reading provenance from ubiquitous quartz: understanding the changes occurring in its lattice defects in its journey in time and space by physical methods”

How to cite: Devi, M., Tóth, Z.-R., Grecu, S.-C., Nesterovschi, I., Constantin, D., Ducea, M. N., Pinzaru, S. C., and Gabor, A. T.: Effect of Metamorphism on the Point Defects in Quartz: Characterization using Different Spectroscopic Techniques , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5922, https://doi.org/10.5194/egusphere-egu25-5922, 2025.

Point defects in quartz and their response to irradiation hold geological significance but are not well understood. They can be analyzed using methods like optically stimulated luminescence (OSL), electron spin resonance (ESR), and scanning electron microscopy with cathodoluminescence (SEM-CL). This study examines point defects in a granite sample (~1.4 Ga crystallization age, ~20–23 Ma cooling age) from the Catalina Metamorphic Core Complex, southwestern USA, part of a Proterozoic anorogenic granitic province.

Defects analyzed include intrinsic ones (e.g., O-vacancies, Si vacancies, and nonbridging oxygen centers) and impurity-related defects (e.g., [AlO₄]⁰ and [TiO₄/M⁺]⁰). ESR identified E', peroxy, Al-, and Ti-related defects, with Al and Ti defects showing higher intensities. The Al-hole center increased exponentially with dose up to 40,000 Gy, while the Ti-electron center showed a nonmonotonic trend, peaking at 10,000 Gy and then decreasing, consistent with Benzid and Timar-Gabor (2020) and Woda and Wagner (2007). Oxygen-related defects were weak and generally dose-independent. OSL decay was dominated by a fast component, and SEM-CL showed strong blue emissions (~450 nm) and weak red emissions (~650 nm, related to NBOHC), confirming Ti-related defect dominance.

One can explain the features of luminescence and ESR signal in quartz, especially their dependence on the irradiation dose, by modelling the charge transport processes during its exposure to high-energy radiation or light. So far, models based on the band theory used in simulations of the luminescence in quartz (e. g. Bailey, 2001) have not considered that, next to electrons, ions also carry the charge in this material. Ionic conduction in quartz is primarily related to interstitial light metal cations M⁺. These ions provide a charge balance in the lattice disturbed by substituting a silicon atom with an aluminium atom at the crystallization stage. Radiation generates free electrons and holes, causing local potential changes that induce cation transport in the crystal. Ionic conduction in quartz requires, therefore, considering, in the modelling, both electronic transitions and changes in the state of ions from bound to free and vice versa.

A kinetic model was developed with differential equations describing M⁺-binding centers (Al and Ti), electronic states, and free electron and ion concentrations. The results, which provide insights into point defect dynamics in granitic quartz, will be discussed at the conference, offering new perspectives.

References:

Benzid, K., Timar-Gabor, A., 2020. Phenomenological model of aluminium-hole ([AlO₄/h⁺]⁰) defect formation in sedimentary quartz upon room temperature irradiation: electron spin resonance (ESR) study, Radiation Measurements, 130,106187.

Woda, C., Wagner, G. A., 2007. Non-monotonic dose dependence of the Ge-and Ti-centres in quartz. Radiation measurements, 42(9), 1441-1452.

Bailey, R. M., 2001. Towards a General Kinetic Model for Optically and Thermally Stimulated Luminescence of Quartz. Radiation Measurements 33: 17-45.

Acknowledgement: This research is funded by European Research Council ERC grant PROGRESS-CoG “Reading provenance from ubiquitous quartz: understanding the changes occurring in its lattice defects in its journey in time and space by physical methods”

How to cite: Tóth, Z.-R., Devi, M., Pawlak, N., Grecu, S.-C., Constantin, D., Dave, A. K., Ducea, M. N., Chruścińska, A., and Timar-Gabor, A.: Understanding defect dynamics under irradiation in quartz: case study of a 1.4 Ga granite sample investigated by multispectroscopic methods, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5985, https://doi.org/10.5194/egusphere-egu25-5985, 2025.

Despite being one of the purest minerals, quartz presents different types of defects, intrinsic or due to impurities, that might contain important genetic information. Its common occurrence is making it a promising tool for provenance studies. This study explores scanning electron microscopy (SEM) coupled with cathodoluminescence (CL) wavelength resolved spectroscopy for investigating luminescence emissions of quartz sourced from rocks of different types, spanning diverse geological ages.

All examined samples display two distinct broad emissions: a blue emission centred at approximately 440 nm (2.7 eV) and a dominant red emission around 650 nm (1.9 eV). The 650 nm (1.9 eV) emission present in quartz samples is attributed to the non-bridging oxygen hole centres (NBOHC). The formation of NBOHCs involves multiple mechanisms, including processes associated with radiation damage in quartz (intrinsic mechanisms) as well as hydrogen- or alkali-passivated precursor defects (extrinsic mechanisms) (Skuja et al., 2020). Making a distinction between the two mechanisms of NBOHC formation is a challenging task that has been rarely adressed. In the long run, we aim to demonstrate that NBOHC defects, which may be inherent to a certain extend since crystallization, could serve as reliable indicators of age, particularly for similar types of samples.

Here we study the dynamics of this defect under 15 keV electron irradiation in SEM. The samples were irradiated for different exposure times. Preliminary results indicate a saturating exponential growth of the red emission. While a growth of the NBOHC under irradiation was previously reported in the literature (e.g. Götze et al., 2021), here we describe this increase in a quantitative manner.

The observed behaviour is well-described by equation S(t) = S(0) * (1- exp(-(t-t₀)/t_c)).

Here, t_c represents the critical time, a measure of the time required for the signal to increase by a factor of 1/e. By determining t_c​, a characteristic saturation time, hence dose can be calculated. While experiments are still in progress, for our experimental setup, t_c values range from 300 to 500 s, depending on the sample. The maximum intensity is not showing significant variation across most samples, with a significant exception for the oldest sample investigated. A noteworthy observation is the non-zero value of t₀​, the time intercept, which suggests that NBOHC exists in the quartz samples since crystallization, before irradiation. In the end, quantifying the exposure to the electron beam in terms of radiation dose (energy delivered per unit mass expressed in Gy) is attempted for facilitating direct comparisons with results obtained by other experimental techniques such as electron paramagnetic resonance or optically stimulated luminescence.

Acknowledgement: This research is funded by European Research Council ERC grant PROGRESS-CoG “Reading provenance from ubiquitous quartz: understanding the changes occurring in its lattice defects in its journey in time and space by physical methods”

References:

Skuja, L., Ollier, N., Kajihara, K. 2020. Luminescence of non-bridging oxygen hole centers as a marker of particle irradiation of α-quartz. Radiation Measurements, Volume 135, 106373.

Götze J., Pan Y. & Müller A. 2021. Mineralogy and mineral chemistry of quartz: A review. Mineralogical Magazine. 85(5):639-664. DOI:10.1180/mgm.2021.72

How to cite: Grecu, Ș.-C. and Timar-Gabor, A.: Characterization of SEM-CL red emission in quartz from various types of rocks, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6869, https://doi.org/10.5194/egusphere-egu25-6869, 2025.

The primary source of clay for ceramic producers in Turkey has historically been the clay extracted from the Şile region and imported from Ukraine. However, the depletion of existing resources and the increase in logistics costs have prompted the sector to explore alternative raw materials. In this context, the stratified sepiolite deposits in Sivrihisar region (Eskişehir, Türkiye) have garnered attention. While these deposits have been utilized in industrial applications, such as cat litter and exported overseas, since the 1970s. The limited physico-chemical properties of sepiolite clay have precluded sufficient investigation into its use in ceramic recipes to date.

Sepiolite formations have been identified within the sedimentary succession of Sakarya Formation Miocene in age. Sepiolite formation is believed to have been sourced from ophiolites, Paleocene-Eocene aged granitoids and marbles. The mineral deposits, which were formed in the lacustrine basins that emerged during tectonic movements, have been converted into sepiolite and dolomite sepiolite deposits in both alkaline and salty environments. However, the absence of lateral continuity in these deposits suggests that their economic viability may be constrained.

This study aims to investigate the potential application of sepiolite and dolomite sepiolite deposits in the Kurtşeyh and Oğlakçı regions of Sivrihisar in the production of wall and floor tiles. The methodology includes geological mapping in both regions, the preparation of stratigraphic sections, and systematic sampling together with the chemical, mineralogical and technological analysis. Geological observations indicate that the sepiolite succession occur in three distinct forms: as pure sepiolite, sepiolite-bearing dolomite, and dolomite-bearing sepiolite. XRD analysis revealed the raw materials to consist of sepiolite ± dolomite ± calcite ± montmorillonite ± palygorskite ± organic ingredients. XRF analysis indicated the prevalence of CaO, SiO₂, and MgO in these clays, with components such as Al₂O₃ and Fe₂O₃ being secondary.

In the laboratory, the thermal properties of the samples were investigated through the application of firing processes. Wall tiles were produced through a 40-minute firing process at 1125°C, while floor tiles underwent a 67-minute firing process at 1185°C. The technological properties of the materials, including density, shrinkage, water absorption, dry strength, and color, were evaluated. The results obtained demonstrated that sepiolite, particularly dolomite sepiolite, can be utilised as an alternative for Istanbul (Şile) and Ukraine clays in ceramic formulations. The adding of 10% of sepiolitic clays into the ceramic mixture exhibited performance that was commensurate with standard production processes.

In conclusion, sepiolite and dolomite sepiolites have been identified as a potential alternative raw material for the ceramic industry in the Kurtşeyh and Oğlakçı regions of Sivrihisar. However, further detailed field studies and industrial-scale trials are required to ensure economic and logistical sustainability.

How to cite: Pocan, H., Doğu, M. M., Yüksel, S., Genç, Ş. C., Kayacı, K., and Yıldırım, Y.: Investigation of Oğlakçı and Kurtşeyh Sepiolites (Eskişehir, Türkiye): As Common Clay Alternatives and Possibilities of Use in Terms of Ceramic Tile Production, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9472, https://doi.org/10.5194/egusphere-egu25-9472, 2025.

Minerals are key markers of the multi-stage processes that occurred in their environment of formation and evolution. We present three micro textural and chemical studies of minerals from lherzolites in the French Massif Central.

-1- Carbonate-bearing mantle xenoliths are interesting as highly mobile carbonate melts are prominent metasomatic agents of the mantle. Here, carbonate fills globular vesicles in composite reaction zones that contain secondary clinopyroxene, olivine, spinel, ± plagioclase and glass. The secondary clinopyroxene and olivine indent or are included in the carbonate crystals. The carbonate is a REE- and alkali-poor calcite with low MgO <1 wt.%.

The presence of rounded vesicles of carbonate is usually interpreted as an evidence for silicate-carbonate liquid immiscibility, but alkali-free immiscible carbonates cannot be almost pure calcite. Here the textural and composition characteristics of carbonates rule out their origin as quenched carbonatitic melts or immiscible carbonate liquids and favor an origin as crystal cumulates from mantle-derived alkali-carbonate melts.

The co-precipitation of carbonate and secondary minerals occurs near the base of the crust. The injection of small amounts of a carbonate-rich melt occurred at mantle level shortly before the eruption to preserve the calcite crystals.

-2- Here we present Li abundances and isotopes data of co-existing silicates in anhydrous and amphibole-bearing lherzolites. Li abundances increase in all phases from the amphibole-bearing lherzolites, but deviate from the trend of equilibrium partitioning between phases with a preferential Li uptake in clinopyroxene. The correlation between Li and REE elements in clinopyroxene suggests that Li and REE were carried by the same silicate melt.

 In the amphibole-bearing lherzolites the  cpx d⁷Li (‰) values show large intra-grain variations. These variations do not provide evidence for different sources but likely result from high temperature diffusion-related Li fractionation during metasomatism by the silicate melt undergoing compositional changes as it percolates through the lherzolites.

The preservation of both the Li isotope kinetic fractionation in minerals and isotopic heterogeneities implies that the Li exchange event occurs just before the extraction of the xenoliths from the mantle.

-3- Glass-bearing pockets in peridotite xenoliths are usually studied for elucidating the origin of the infiltrating agent. We present here a chemical study of glass developed around spinels. We do not discuss the origin of the metasomatic agent but show that 1) the modification of the structure of the percolating melt is due to the accommodation of elements produced by the dissolution of minerals and (2) how this process could modify the oxidation state of the melt.

Spinel-derived Al³⁺ ions are first accommodated to the melt network as network-modifiers and secondly as network-formers using K⁺ ions as stabilizators within the tetrahedral site. The transfer of K⁺ ions (extracted from the aqueous fluid upon melt dehydration) from the aqueous fluid to the melt network is counterbalanced by an inverse transfer of CaO molecules that form crystalline phases exsolved upon eruption.

Spinel corrosion generates melt oxidation through dehydrogenation reactions resulting in the formation of Al³⁺ and Fe³⁺ anionic complexes within the melt network.

How to cite: Wagner, C., Boudouma, O., Fialin, M., and Deloule, E.: Minerals as key tools for characterizing multi-stage processes in the lithospheric mantle., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13622, https://doi.org/10.5194/egusphere-egu25-13622, 2025.

The central Yukon Territory is renowned for its exceptionally abundant beryl occurrences. In 2003, widespread medium-blue aquamarine mineralization was discovered in the Black River Batholith, south-central Yukon. This aquamarine occurrence is notable because it is hosted in granodiorite, rather than being associated with pegmatites. Four distinct beryl occurrences have been documented in the batholith: (1) beryl with tourmaline, separated from the granodiorite by an aplite zone; (2) beryl with tourmaline bordering the granodiorite, with no aplite; (3) a set of beryl-quartz veins devoid of tourmaline, striking 70° and dipping 60° south; and (4) a second set of veins striking 315° and sub-vertical.

This study aims to: first, compare the different types of aquamarine occurrences and identify distinguishing features; second, compare this occurrence with the Tsa Da Glisa emerald deposit (15 km northeast) and the true blue aquamarine locality (150 km northwest); and third, determine an accurate age for the Black River Batholith and compare it with nearby intrusions.

The Black River Batholith, in the Finlayson Lake map area, is an Eocene-aged granitic intrusion emplaced within Cambrian to Lower Cambrian sedimentary rocks of the Kechika Group and Rosella Formation. It forms part of the geologically complex Canadian Cordillera, an orogenic belt formed by terrane accretion onto the Laurentian craton. Structurally, the batholith lies between the Tintina Fault to the north and the St. Cyr Thrust Fault to the southeast, with an elongated morphology aligned with these structures. These features suggest a complex tectonic evolution, potentially influenced by post-accretionary transcurrent faulting.

The batholith is predominantly peraluminous, consisting of K-feldspar-phyric monzogranite to granodiorite, with accessory minerals like biotite, muscovite, and tourmaline. Previous geochronological investigations yielded discordant ages, with K-Ar dating of biotite ranging from 46.9 ± 2.6 Ma to 68 Ma. Nearby lithologically similar intrusions yielded K-Ar ages of 70 to 100 Ma, indicating either a distinctive emplacement history for the Black River Batholith, deficiencies in earlier dating methods, or subsequent reheating events.

This study employs U-Pb zircon geochronology and whole-rock geochemical analysis to clarify the temporal and compositional relationships of the Black River Batholith with nearby intrusions and test its affiliation with the Cassiar Suite. Geochemical analysis of beryl-bearing and non-beryl-bearing granitoids will help delineate the chemical provenance of the beryl occurrences. Additionally, we will use SEM and EPMA to investigate compositional variations among beryl occurrences and zoning within individual beryl crystals, providing insights into their chemical affinities and source divergences. This integrated approach aids in reconstructing the Black River Batholith’s emplacement history and enhances our understanding of the region's magmatic evolution.

This study is significant because it addresses long-standing uncertainties regarding the batholith’s emplacement age, its relationship to nearby intrusions, and the origins of its unusual beryl occurrences. These occurrences have not been studied in detail before and may provide valuable insights into magmatic-hydrothermal processes in the region.

How to cite: Groat, L., Ozyalcin, C., and Breasley, C.: Aquamarine Mineralization in the Black River Batholith, Yukon Territory, Canada, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15015, https://doi.org/10.5194/egusphere-egu25-15015, 2025.

The albite breakdown reaction to jadeite and quartz is frequently utilized for the calibration of piston-cylinder apparatuses due to its well-established and highly precise equilibrium conditions. In nature, jadeitic pyroxene serves as an indicator for high-pressure conditions during metamorphism. Quite a few granites can be found in association with mafic eclogites, so that jadeite + quartz would be expected to be common. While jadeite has been documented in a number of locations, it is often absent in continental high-pressure rocks. Several possible explanations for the absence of jadeite have been proposed; a) the nominally dry reaction may be kinetically too slow in the absence of free water in the system; b) complete retrogression of jadeite paragenesis by later lower pressure metamorphism, or c) that the pressure gradients between mafic eclogites and granites lead to P-T conditions that prevent jadeite formation.

This experimental study aims to determine whether jadeite can form without free water or if slow reaction kinetics hinder its formation. Isochemical phase diagrams have been calculated within the NCKFMASH system to model the water acitivity. It is shown, that biotite breakdown at elevated P-T conditions may provide free water on the grain boundaries even at nominally dry experimental conditions, thus increasing water activity and passively promote jadeite formation. To investigate this effect, three sets of piston-cylinder experiments are conducted using natural granite (100-400 µm). The experiments were annealed just outside the jadeite stability field to eliminate grain boundary water introduced by the powder, before exposing them to eclogite facies conditions. Kyanite is added in some experiments to induce the formation of white mica, thereby reducing the water activity by adsorbing the water in the crystal lattice.

The results of this study will elucidate whether jadeite formation is kinetically inhibited in the absence of free water. If jadeite forms only when free water is present during the reaction, it can be concluded that indeed sluggish kinetics, driven by the absence of free water, impede jadeite formation in high-pressure metagranites.

How to cite: Abel, A., Müller, T., Sorger, D., and Baumgartner, L.: The role of water on the reaction kinetics of a nominally dry reaction: Experimental study on the albite breakdown to form jadeite and quartz, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16735, https://doi.org/10.5194/egusphere-egu25-16735, 2025.

  Cosmic processes, geological processes and human activities on Earth introduce dust, gases, and aerosols into the atmosphere. Various reactions between them take place, including photochemical reactions, and new compounds are formed. Particulate matter is transported in the atmosphere sometimes over global distances and remains suspended even for many years. The phase composition of atmospheric dust, on a par with its chemical and isotopic composition, are the “fingerprints” for determining its source, transformation processes and health effects. Mineralogical analysis of the presence and distribution of particles in the atmosphere, their quantity, diversity and routes of transport is a powerful tool in modern studies of global environmental transformations.

  The term aeromineralogy was proposed for that part of mineralogy that addresses such issues (Manecki, 1976, Manecki et al., 1984), following the example of biologists who called aerobiology the branch of biology that studies the aeroplankton floating in the atmosphere. To study the mineral and chemical composition of atmospheric dust, aeromineralogy uses specific methodology: specific tools for collection and separation of the particles followed by microscopy (polarizing microscopes, electron microscopes, atomic force microscopy, etc.), diffraction methods (X-ray diffractometry, electron diffraction, EBSD, etc. ), different varieties of microprobes for chemical and isotopic microanalysis, spectroscopy for determination of H₂O, OH, and organic matter (IR, Raman, etc.) and many other less classical methods from the mineralogist workbench. Comprehensive analyses of airborne particulate matter are routinely performed for both research and monitoring purposes, for health protection, both indoors and outdoors, since not only the size of inhaled particles, but also their phase composition accounts for potential hazards or health effects (see for example Peña-Castro et al., 2023; Puławska et al., 2021).

  Therefore, it is advisable to more broadly publicize the name aeromineralogy for the promotion of the contribution, role, and specificity of mineralogical research and analytical methods in everyday applications of occupational health and safety practice, in the monitoring of contemporary global environmental changes, the circulation of atmospheric particles on Earth, and in studies of cosmic matter (see for example Genge et al., 2020).

Genge et al., 2020. Micrometeorites: Insights into the flux, sources and atmospheric entry of extraterrestrial dust at Earth. Planetary and Space Science. https://doi.org/10.1016/j.pss.2020.104900.

Manecki, A. 1976. Aeromineralogy, mineralogy of atmospheric dust. Mineral. Polon., vol. 7, no. 2.

Manecki A. (ed.) 1984. Transport and input of air pollutants in the Niepołomice Forest area. In: Forest Ecosystems in Industrial Regions. Ecol. Stud., 48. Springer.

Peña-Castro et al., 2023. A critical review of asbestos concentrations in water and air, according to exposure sources. Heliyon. https://doi.org/10.1016/j.heliyon.2023.e15730.

Puławska et al., 2021. Origin, distribution, and perspective health benefits of particulate matter in the air of underground salt mine: a case study from Bochnia, Poland. Environ Geochem Health, https://doi.org/10.1007/s10653-021-00832-2

How to cite: Manecki, M. and Manecki, A.: Aeromineralogy - mineralogy of solid particles in the atmosphere, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17164, https://doi.org/10.5194/egusphere-egu25-17164, 2025.

Zeolites form in various geological environments; among all, volcanic materials are the most important zeolite precursors. In this study, zeolites were synthesized by hydrothermally treating the volcanic material. The fine powdered pumice sample, used in this study, is one of the pyroclastic products of the Central Anatolian Volcanic Province (CAVP). This study mainly focused on the phase-transition and characteristics of zeolites formed under different reaction agent contents in a hydrothermal synthesis reactor. The products of the hydrothermal treatment were characterized using various analytical techniques, such as X-ray diffraction, scanning electron microscopy, and FTIR measurements. The hydrothermal treatment was performed with NaOH (1M, 2M, and 3M) and 1M KOH reaction agents at 150 ºC for 8 to 16 h. Meanwhile, diatomite is specifically utilized in this study to observe its impact on the reaction and to increase the silica content of the starting material. The crystallinity and characteristics of the reaction products were affected by the molar concentration and type of the reaction agents. The products mainly consist of analcime, chabazite, Na-phillipsite, and Na-P1. The alumina-silicate gel produced by the reaction of 2M NaOH with natural volcanic material has the potential to transform into chabazite and Na-P1. With the increase in molar concentration of NaOH, more sodium participates in the reaction to form zeolite phases of analcime, Na-P1, and Na-phillipsite. Following the addition of diatomite to the reaction with 3M NaOH, it has been noted that Na-Al-Si-rich gel has been produced beside analcime, Na-P1, and Na-phillipsite. The results obtained in this study showed that natural volcanic material led to the formation of gels under different alkaline activation conditions, which seemed to control the generation of zeolites.

How to cite: Akın, L. and Çubukçu, H. E.: Phase transformation and characteristics of hydrothermal zeolites formed under alkaline conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11641, https://doi.org/10.5194/egusphere-egu25-11641, 2025.