Physics and Chemistry of Minerals最新文献

{"title":"Filling the gap between lansfordite and nesquehonite: MgCO3·4H2O, a new magnesium carbonate hydrate","authors":"Guntram Jordan,&nbsp;Samuel B. Strohm,&nbsp;Aleksandar Živković,&nbsp;Giacomo Criniti,&nbsp;Kai-Uwe Hess,&nbsp;Melanie Kaliwoda,&nbsp;Elena V. Sturm,&nbsp;Daniel Weidendorfer","doi":"10.1007/s00269-026-01349-9","DOIUrl":"10.1007/s00269-026-01349-9","url":null,"abstract":"<div>\u0000 \u0000 <p>Formation conditions, transformation mechanisms, and transformation product selection of magnesium carbonate hydrate phases at temperatures near the freezing point of water are poorly understood. In this study, carbonated Mg(OH)₂ suspensions were aerated at <i>T</i> = 0 °C to obtain solutions from which either MgCO₃·6H₂O or lansfordite (MgCO₃·5H₂O) precipitated, with the selected phase depending on the aeration rate. Subsequently, magnesium carbonate hexahydrate was subject to transformation experiments yielding five different products. The product selection depended on the transformation condition. Among the products, a new phase was identified and characterized as a neutral magnesium carbonate hydrate with the chemical composition MgCO₃·4H₂O. Implications of the synthesis route and analytical results suggest that this tetrahydrate phase forms from MgCO₃·6H₂O by the release of two weakly bonded water molecules per formula unit, accompanied by a relaxation of the remaining MgCO₃·4H₂O layers without disrupting the edge-sharing octahedral pairs of the parental structure. Density functional theory calculations confirmed the stability of the proposed crystal structure through the examination of its phonon dynamics and subsequent vibrational analysis. Furthermore, the simulated X-ray powder diffraction pattern is in reasonable agreement with the experimental data when accounting for the high crystalline disorder inevitably introduced by the transformation process.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-026-01349-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of molybdenum and vanadium substitution in langbeinite phosphates: structural and thermal expansion investigation of KPbCr2P3−xMxO12 (M = V, Mo and x = 0.1, 0.2)","authors":"Daneshwaran Balaji,&nbsp;Triveni Rajashekhar Mandlimath,&nbsp;Sathasivam Pratheep Kumar","doi":"10.1007/s00269-026-01348-w","DOIUrl":"10.1007/s00269-026-01348-w","url":null,"abstract":"<div>\u0000 \u0000 <p>This research work reports synthesis, characterization and thermal expansion investigation of vanadium and molybdenum substituted langbeinite phosphates with the chemical formula KPbCr₂P_2.9V_0.1O₁₂, KPbCr₂P_2.8V_0.2O₁₂ and KPbCr₂[P_2.9Mo_0.1]^+0.1O₁₂, KPbCr₂[P_2.8Mo_0.2]^+0.2O₁₂. All the four-materials exhibit phase pure cubic structure with <i>P2</i>_<i>1</i><i>3</i> space group. Rietveld refinement studies authenticate the single-phase formation with the least chi square values. The lattice parameters and lattice volume increased upon the substitution of bigger of VO₄ and MoO₄ for smaller PO₄ group in the framework. The morphological and elemental mapping investigation reveal the crystalline nature of materials, shape of the particles and distribution of the elements. The peak shift and peak broadness in the vibrational modes of FTIR spectra affirms that the VO₄ and MoO₄ tetrahedral groups have effectively been substituted for the PO₄ tetrahedra. The average coefficient of thermal expansion of KPbCr₂P_2.8V_0.2O₁₂ and KPbCr₂[P_2.8Mo_0.2]^+0.2O₁₂ is found to be 1.44 × 10^− 6 / K and 1.04 × 10^− 6 / K.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal synthesis and formation of a synthetic analogue of reichenbachite, Cu5(PO4)2(OH)4","authors":"Marley E. J. Knight,&nbsp;Sian E. Woodfine,&nbsp;Richard J. Darton","doi":"10.1007/s00269-026-01347-x","DOIUrl":"10.1007/s00269-026-01347-x","url":null,"abstract":"<div>\u0000 \u0000 <p>Reichenbachite (Cu₅(PO₄)₂(OH)₄) is a rare copper-hydroxy-phosphate, the synthetic accessibility and phase evolution of which are still poorly understood. Here we report the first known reproducible hydrothermal synthesis to yield high purity reichenbachite, facilitated by alkaline conditions at 180 °C. Systematic time-controlled experiments clearly reveal a kinetic-thermodynamic bias: pseudomalachite forms rapidly as the metastable kinetic phase and reichenbachite emerges as the thermodynamic product after extended reaction times. Powder X-ray diffraction experiments combined with Rietveld refinements confirm phase selectivity as an outcome of reaction conditions. Scanning electron microscopy shows characteristic morphological features of each polymorph. Through a combination of order–disorder theory, classical nucleation theory, and Ostwald’s rule of stages we propose a mechanism of formation through polymorphic interconversion driven by synthesis duration and alkalinity. This study not only establishes a new reproducible synthesis for a previously elusive mineral but also provides insights into fundamental metastable-equilibrium phase transitions in copper hydroxy-phosphate systems, with implications for crystal growth theory and design of functional phosphate-materials.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-026-01347-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147607260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation of state of nitrogen-bearing K-cymrite","authors":"Alexandr V. Romanenko,&nbsp;Sergey V. Rashchenko,&nbsp;Alexander G. Sokol,&nbsp;Andrey V. Korsakov","doi":"10.1007/s00269-026-01346-y","DOIUrl":"10.1007/s00269-026-01346-y","url":null,"abstract":"<div>\u0000 \u0000 <p>Nitrogen-bearing K-cymrite (K, NH₄)AlSi₃O₈·(N₂,NH₃,H₂O), a clathrate phase that is stable in subduction zones, may play a crucial role in transporting potassium, water, and nitrogen to the depths of the mantle. Synchrotron X-ray diffraction in a diamond anvil cell with a methanol-ethanol medium was used to study its compressibility up to 10 GPa. N-bearing K-cymrite retains its hexagonal <i>P</i>6/<i>mmm</i> symmetry without signs of phase transitions across the pressure range. The third-order Birch-Murnaghan equation of state yielded the following values: <i>V</i>₀ = 191.38(3) ų, <i>K</i>₀ = 47.1(2) GPa, and <i>K</i>₀’ = 6.40(7). Unlike K-cymrite KAlSi₃O₈·H₂O, which develops incommensurate modulation above 7–8 GPa, no satellite reflections appear in the diffraction patterns of N-bearing K-cymrite, even at 16 GPa. This suggests that N₂ stabilizes the double tetrahedral layers against wave-like bending.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Equation of state and structural variations of synthetic forsterite-fayalite solid solution by single-crystal X-ray diffraction","authors":"Zhilin Ye,&nbsp;Jingui Xu,&nbsp;Dongzhou Zhang,&nbsp;Weiyi Liu,&nbsp;Wenge Zhou,&nbsp;Dawei Fan","doi":"10.1007/s00269-026-01341-3","DOIUrl":"10.1007/s00269-026-01341-3","url":null,"abstract":"<div>\u0000 \u0000 <p>Olivine, a predominant mineral in the Earth’s upper mantle, plays a crucial role in geophysical and geochemical processes due to its abundance and elastic characteristics. This study investigates the elastic properties and structural variations of synthetic forsterite-fayalite solid solutions under high-pressure conditions through synchrotron single-crystal X-ray diffraction. A series of samples with varying fayalite contents were synthesized and characterized to evaluate the impact of Fe incorporation on unit-cell parameters, bulk modulus, and compression behavior. The results demonstrate that increasing fayalite content elongates the <i>b</i>-axis, increases polyhedral distortions, and enhances the bulk modulus, while maintaining the structural rigidity of [SiO₄] tetrahedra. By refining the fit parameters of the Birch-Murnaghan equation of state, this study establishes a composition-property relationship for elastic behavior. These results provide key constraints for modeling mantle dynamics and planetary evolution.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights of origin determination and formation of emeralds from Afghanistan (Panjshir Valley) and Pakistan (Swat Valley): constraints from spectroscopy and LA-ICP-MS test","authors":"Zhiyi Zhang,&nbsp;Bo Xu,&nbsp;Siyi Zhao","doi":"10.1007/s00269-026-01343-1","DOIUrl":"10.1007/s00269-026-01343-1","url":null,"abstract":"<div><p>The identification of the geographic origin of emeralds constitutes a crucial technique in gemological laboratories and holds a prominent position as a research focus within the gemology field. The proximity of the emerald deposits in Panjshir Valley, Afghanistan, and Swat Valley, Pakistan (just 250 km apart) and their shared formation age of 23 Ma pose significant challenges in distinguishing the origins of the emeralds from these two locations. Furthermore, the mineralization patterns of the emeralds from these two sites are not yet fully understood. The inclusion, spectroscopy characteristics and chemical composition of emeralds from these two deposits were systematically analyzed in this study through basic gemological tests, spectroscopic tests (infrared, UV-VIS-NIR and Raman spectroscopy), and major and trace element tests (LA-ICP-MS). There are a greater variety of inclusions in Pakistani emeralds, and that pyrite stands out as the most common inclusion found in emeralds from both sources. The patterns and frequencies of infrared and UV-VIS-NIR spectra of emeralds from the two deposits exhibit considerable promise for identifying their origins. As for the genesis of the two deposits, the low Li, Rb, and Cs contents of emeralds from both localities suggest that the ore-forming fluid was of metamorphic origin. The high Sc content of both is related to albitization of host rocks (Panjshir Valley) and deep hidden leucogranite (Swat Valley). This study provides an appropriate case for the origin identification by spectroscopic characteristics, proposes the element content standard for testing the source of ore-forming fluid, and verifies the geological characteristics of the two deposits through the element content.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"‌ Impact of minor aluminum incorporation on the high-pressure properties of stishovite","authors":"Shuo Qu,&nbsp;Yuhui Jiang,&nbsp;Li Zhang,&nbsp;Peiyan Wu,&nbsp;Xiaofeng Lu,&nbsp;Jinpu Liu","doi":"10.1007/s00269-026-01344-0","DOIUrl":"10.1007/s00269-026-01344-0","url":null,"abstract":"<div>\u0000 \u0000 <p>Stishovite is a key constituent of subducting oceanic crust. Outside the stability fields of dense hydrous magnesium silicates, it remains stable in high-temperature regions of the deep mantle and serves as a significant reservoir for hydrogen. Numerous studies show that stishovite can incorporate over 3 wt% Al₂O₃, which can significantly lower the pressure required for the stishovite-to-post-stishovite phase transition. However, the stability of Al-rich stishovite under typical upper-mantle P-T conditions remains uncertain. Furthermore, the effect of even minor Al contents on this transition pressure requires further investigation. In this study, high-pressure and high-temperature synthesis experiments of Al-bearing stishovite were conducted at 11 GPa and 1300 °C under hydrous conditions. The results show no evidence for the existence of Al-rich stishovite in the base of the upper mantle. Furthermore, in situ high-pressure Raman spectroscopy performed on synthesized low-Al stishovite samples (up to 42 GPa at room temperature) reveals that the presence of a small amount of aluminum (1.41–1.57 wt% Al₂O₃) in stishovite reduces the pressure required for the stishovite–post-stishovite phase transition by at least 20 GPa. Compared to aluminum, hydrogen do not significantly affect this phase transition.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural disorder in Fe-bearing topaz-OH revealed by single-crystal X-ray diffraction","authors":"Baoyun Wang,&nbsp;Meisu Xiang","doi":"10.1007/s00269-026-01342-2","DOIUrl":"10.1007/s00269-026-01342-2","url":null,"abstract":"<div><p>Topaz-OH phases, including structurally distinct but chemically identical topaz-OH I and topaz-OH II, are considered as potential water carriers in hydrated subducted sediments. In this study, Fe-bearing topaz-OH I was synthesized at 15.5 GPa and 1400 °C, with a chemical composition of Al_1.94±0.05Fe_0.18±0.01Si_0.69±0.02O₆H_2.88±0.13. Its crystal structure is similar to that of the ordered Al-endmember topaz-OH I (Al₂SiO₆H₂), with both exhibiting the same <i>Pbnm</i> space group and comparable unit cell parameters. However, this structure contains evident vacancies in the tetrahedral sites and new occupied octahedral sites that are normally vacant in the ordered Al-endmember topaz-OH I. Our structural model represents a transitional phase between the Al/Si-ordered topaz-OH I and the fully Al/Si-disordered topaz-OH II. These findings suggest that structural disorder may play a key role in influencing the tetrahedral-to-octahedral occupancy ratio, the evolution of crystal structures, and the thermal stability of topaz-OH under the high pressure-temperature conditions of the deep mantle.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking feldspar luminescence phenomena and mineralogy using spatially resolved techniques","authors":"Svenja Riedesel,&nbsp;Geoff A. T. Duller,&nbsp;Max Hellers,&nbsp;Nick J. G. Pearce,&nbsp;Joseph A. Winzar,&nbsp;Anthony M. T. Bell,&nbsp;Reiner Kleinschrodt","doi":"10.1007/s00269-026-01345-z","DOIUrl":"10.1007/s00269-026-01345-z","url":null,"abstract":"<div><p>Feldspars, the most abundant mineral group in the Earth’s crust, exhibit a striking chemical and structural variety resulting from variations in their crystallisation environments and post-crystallisation processes. Since feldspars record both formation and alteration processes and conditions, they are key components in geological studies and valuable for developing tools to reconstruct past environmental change. Thermally and optically stimulated luminescence, the ability of minerals, such as feldspars, to emit light in different wavelengths upon excitation with light or heat, are sensitive to changes in the crystal lattice and thus may have the potential to be used as a tool for identifying crystallisation and alteration processes affecting feldspars. So far, the luminescence of feldspars has primarily been used as a numerical geochronological dating technique, constraining past geological and archaeological events and processes. However, the sensitivity of feldspar luminescence signals to changes in crystallisation and post-crystallisation processes allows for the development of luminescence-based proxies beyond geochronological studies.</p><p>This study investigates the relationship between luminescence emission intensities in three emission bands and mineralogical features in 13 alkali feldspars and plagioclases using spatially resolved luminescence techniques, electron microprobe analysis, bulk geochemistry, and X-ray powder diffraction. The intensity of infrared photoluminescence (IRPL) emission (~ 900 and ~ 950 nm) is particularly sensitive to chemical and structural heterogeneities within the feldspar samples, such as the presence of K-rich phases, fractures, and alteration products. Blue (~ 400 nm) thermoluminescence (TL) and infrared stimulated luminescence (IRSL) emission intensities vary with feldspar type and perthitic texture, while yellow-green (~ 560 nm) TL and IRSL emissions are linked to fluid-induced alteration of the feldspar chemistry and structure. These findings highlight the potential of spatially resolved luminescence measurements as a non-destructive tool for identifying crystallisation and alteration processes in feldspars, as well as relationships between luminescence signal intensity and mineralogical properties, advancing both geochronological techniques which use these emissions, and mineralogical studies.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-026-01345-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Alloyed cementite (Fe–Ni–Cr)3C: structure and hyperfine field from DFT calculations and experimental comparison","authors":"L. V. Dobysheva","doi":"10.1007/s00269-026-01340-4","DOIUrl":"10.1007/s00269-026-01340-4","url":null,"abstract":"<div>\u0000 \u0000 <p>The alloying elements introduced into carbon steel to enhance its mechanical properties also diffuse into cementite (Fe₃C) particles, modifying their characteristics and thereby influencing the overall performance of the steel. This study employs density functional theory (DFT) calculations to investigate cementite doped with Ni and Cr which exhibit contrasting effects. The preferred lattice sites of impurity atoms were determined through a comparison of calculated and experimental structural parameters. The formation mechanism of the hyperfine magnetic field (HFF) and its correlation with atomic magnetic moments were systematically investigated. The validity of common approximations in Mössbauer spectroscopy analysis was evaluated for the cementite system. HFF distribution functions were modeled using calculated values and compared with experiments.</p>\u0000 </div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"53 2","pages":""},"PeriodicalIF":1.6,"publicationDate":"2026-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147336520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}