Physics and Chemistry of Minerals最新文献

{"title":"Compressional behavior of the aragonite-structure carbonates to 6 GPa","authors":"Isaac Vidal-Daza,&nbsp;Antonio Sánchez-Navas,&nbsp;Alfonso Hernández-Laguna","doi":"10.1007/s00269-023-01237-6","DOIUrl":"10.1007/s00269-023-01237-6","url":null,"abstract":"<div><p>The behaviors of aragonite (CaCO<span>(_3)</span>), strontianite (SrCO<span>(_3)</span>), cerussite (PbCO<span>(_3)</span>), and witherite (BaCO<span>(_3)</span>) at increasing pressure have been studied up to 6 GPa using density functional theory with plane waves. A parallelism of the orthorhombic carbonates with the closed-packed AsNi structure is considered in our analysis, being the CO<span>(_3^{2-})</span> groups not centered in the interstice of the octahedron. The decomposition of the unit-cell volume into atomic contributions using the Quantum Theory of Atoms in Molecules has allowed the analysis of the bulk modulus in atomic contributions. The bulk, axes, interatomic distances, and atomic compressibilities are calculated. The largest compression is on the <i>c</i> crystallographic axis, and the <i>c</i> linear modulus has a linear function with the mineral bulk modulus (<span>(K_0)</span>). Many of the interatomic distances moduli of the alkaline earth (AE) carbonates show linear functions with the bulk modulus; however, the whole series (including cerussite) only gives linear functions when <span>(K_0)</span> is related either with the <i>CC</i> distances modulus or the modulus of the distances of the <i>C</i> to the faces of the octahedron perpendicular to <i>c</i>. These last distances are the projections of the Metal–Oxygen (MO) distances to the center of the octahedron. <span>(K_{0AE})</span> carbonates also show linear functions with the atomic moduli of their cations. However, the whole series show a linear relation with the atomic modulus of <i>C</i> atoms. Therefore, the whole series highlight the importance of the <i>C</i> atoms and their interactions in the mechanism of compression of the orthorhombic carbonate series.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 2","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01237-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4197601","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":"An experimental study of proton implantation in olivine","authors":"Thilo Bissbort,&nbsp;Qinting Jiang,&nbsp;Hans-Werner Becker,&nbsp;Varvara Foteinou,&nbsp;Sumit Chakraborty","doi":"10.1007/s00269-023-01234-9","DOIUrl":"10.1007/s00269-023-01234-9","url":null,"abstract":"<div><p>Implantation of ions in minerals by high energy radiation is an important process in planetary and materials sciences. For example, the solar wind is a multi-ion flux that progressively modifies the composition and structure of near-surface domains in solar objects, like asteroids. A bombardment of a target by different elements like hydrogen (H) at various energies causes, among other things, the implantation of these particles in crystalline and amorphous materials. It is important to understand the mechanisms and features of this process (e.g., how much is implanted and retained), to constrain its contribution to the chemical budget of solar objects or for planning various material-science applications. Yet, there has been no detailed study on H implantation into olivine (e.g., the quantification of maximum retainable H), a major mineral in this context. We performed experiments on H implantation in San Carlos olivine at 10 and 20 keV with increasing fluences (up to 3×10¹⁸ at/cm²). Nanoscale H profiles that result from implantation were analyzed using Nuclear Resonance Reaction Analysis after each implantation to observe the evolution of the H distribution as a function of fluence. We observed that after a systematic growth of the characteristic, approximately Gaussian shaped, H profiles with increasing fluences, a maximum concentration at H ~ 20 at% is attained. The maximum concentration is approximately independent of ion energy, but the maximum penetration depth is a function of beam energy and is greater at higher energies. The shapes of the profiles as well as the maximum concentrations deviate from those predicted by currently available models and point to the need for direct experimental measurements. We compared the depth profiles with predictions by SRIM. Based on observations from this study, we were able to constrain the maximum retainable H in olivine as a function of ion energy.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 2","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01234-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4197588","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":"Thermal expansion of anhydrous copper sulfate minerals determined by single crystal X-ray diffraction: chalcocyanite CuSO4, dolerophanite Cu2OSO4 and kamchatkite KCu3O(SO4)2Cl","authors":"Evgeny V. Nazarchuk,&nbsp;Oleg I. Siidra,&nbsp;Stanislav K. Filatov,&nbsp;Dmitri O. Charkin,&nbsp;Lada R. Zhdanova","doi":"10.1007/s00269-023-01236-7","DOIUrl":"10.1007/s00269-023-01236-7","url":null,"abstract":"<div><p>Polythermic single-crystal X-ray studies of chalcocyanite CuSO₄, dolerophanite Cu₂OSO₄, and kamchatkite KCu₃O(SO₄)₂Cl have established their melting points as well as peculiarities of their thermal expansion. Association of oxocentered and sulfate tetrahedra in dolerophanite and kamchatkite leads to the formation of rigid tetrahedral “backbones” only slightly sensitive to thermal variations. Rigid complexes can also be distinguished in the structure of chalcocyanite, if we consider only the system of the shortest and strongest Cu–O and S–O bonds. The anisotropy of the thermal expansion can be explained by either rigid complexes drifting parallel to each other (as in dolerophanite and chalcocyanite), or radial and angular distortions in the polyhedra of alkali cations. The presence of a tetrahedrally coordinated additional oxygen atom in the structure of dolerophanite and kamchatkite leads to an increase in the principal eigenvalues. The demonstrated rigidity of the sulfate tetrahedra in studied anhydrous copper sulfate minerals explains the absence of phase transitions up to the melting temperatures. The variation of chemical composition leads to changes in their thermal decomposition points. Chlorine-containing kamchatkite decomposes at the lowest temperature of 590(5) K, next are chalcocyanite 675(10) K, and dolerophanite 925(10) K.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 2","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4149868","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":"Nanomechanics of minerals: understandings and developments through instrumented nanoindentation techniques","authors":"Rajiv Mukherjee,&nbsp;Santanu Misra","doi":"10.1007/s00269-023-01235-8","DOIUrl":"10.1007/s00269-023-01235-8","url":null,"abstract":"<div><p>Understanding the dynamics of the lithosphere relies heavily on the scale-dependent rheology of minerals. While quartz, feldspar, and phyllosilicates are the key phases to govern the rheology of the crust and tectonic margins, olivine and other mafic phases control the same in the upper mantle. Phase transition, solid-state substitution, polymorphism, etc. also affect mineral phase rheology. High pressure–temperature deformation tests with natural, synthetic and analog materials have improved our interpretation of the geodynamic state of the lithosphere. However, deforming and studying a single crystal is not easy, because of the scarcity of specimens and laborious sample preparations. Experimental micro- to nanoindentation at room and/or elevated temperatures has proven to be a convenient method over mesoscale compressive testing. Micro- to nanoindentation technique enables higher precision, faster data acquisition and ultra-high resolution (nanoscale) load and displacement. Hardness, elastic moduli, yield stress, fracture toughness, fracture surface energy and rate-dependent creep of mono- or polycrystalline minerals are evaluated using this technique. Here, we present a comprehensive assessment of micro- to nano-mechanics of minerals. We first cover the fundamental theories of instrumented indentation, experimental procedures, pre- and post-indentation interpretations using various existing models followed by a detailed discussion on the application of nanoindentation in understanding the rheology and deformation mechanisms of various minerals commonly occur in the crust and upper mantle. We also address some of the major limitations of indentation tests (e.g., indentation size effect). Finally, we suggest potential future research areas in mineral rheology using instrumented indentation.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01235-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5081721","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":"Mineralogical characterization of fluorescent grossular garnet var. tsavorite from Merelani Hills, Tanzania","authors":"Alfredo Idini,&nbsp;Celestino Angeli,&nbsp;Franco Frau,&nbsp;Guido Ennas,&nbsp;Stefano Naitza,&nbsp;Giovanni Battista De Giudici,&nbsp;Roberto Argazzi","doi":"10.1007/s00269-023-01233-w","DOIUrl":"10.1007/s00269-023-01233-w","url":null,"abstract":"<div><p>Tsavorite is the trade name for the green vanadium–chromium variety of grossular occurring in the Precambrian terrains in the areas of Merelani Hills (Tanzania) and Tsavo Park (Kenya) which are by far the most important source of gem grade specimens of tsavorite used for high jewellery. The tsavorite crystals from Merelani Hills exhibit a pink-red and yellow fluorescence when irradiated by common portable UV lamp, an unusual phenomenon among members of the garnet group. The electron density map calculated from the diffraction data and plotted against a grossular standard shows that an excess of negative charge is clearly pinpointed in the crystallographic site occupied by Al³⁺. The bulk elemental analysis shows that the most represented end-member, besides grossular, is the vanadium-bearing goldmanite garnet (3.82–4.08 mol %). The fluorometry with an excitation beam at 408 nm indicates a complex emission pattern with the most intense emissions at 701 and 716 nm and subordinately at 592 nm. The colour perception is dominated by the emission yellow band at 592 nm while the contribution of the red band modulates the colour ranging from bright orange to pink-red. The attribution of the emission at 592 nm is related to Mn²⁺ while the emissions at 701 and 716 nm could be related to the chromium content and/or to a possible fraction of vanadium as V²⁺. Because of the characteristic colour perceived under UV light, the use of a common led lamp can be useful as a diagnostic tool to easily identify tsavorite.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01233-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4645563","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":"Mechanisms and conditions of Ti and Cr incorporation in mantle phlogopite: the results of atomistic simulation","authors":"Aleksandra A. Bendeliani,&nbsp;Nikolay N. Eremin,&nbsp;Andrey V. Bobrov","doi":"10.1007/s00269-023-01232-x","DOIUrl":"10.1007/s00269-023-01232-x","url":null,"abstract":"<div><p>Modeling of eight mechanisms for the incorporation of Ti⁴⁺ and Cr³⁺ impurity components into phlogopite was carried out by a semi-empirical method using the GULP (General Utility Lattice Program) software. The calculation of thermodynamic mixing properties in the range of 1–7 GPa and 373–1573 K and the analysis of the structure geometry for the simulated solid solutions provided the following energy-preferred schemes of isomorphic substitution: ^VI(Mg²⁺) + 2^IV(Si⁴⁺) = ^VI(Ti⁴⁺) + 2^IV(Al³⁺) and ^VI(Mg²⁺) + 2^IV(Al³⁺) = ^VI(□) + 2^IV(Ti⁴⁺), ^VI(Mg²⁺) + ^IV(Si⁴⁺) = ^VI(Cr³⁺) + ^IV(Al³⁺), and 3^VI(Mg²⁺) = ^VI(Al³⁺) + ^VI(Cr³⁺) + ^VI(□). It is shown the scheme 2^VI(Mg²⁺) = ^VI(Ti⁴⁺) + ^VI(□) illustrating entrance of Ti with the formation of a vacancy is realized in the case of microconcentrations of Ti only. Accumulation of high-Ti contents associates with the formation of a vacancy in the octahedral site. This provides incorporation of Ti via the schemes ^VI(Mg²⁺) + 2^IV(Al³⁺) = ^VI(□) + 2^IV(Ti⁴⁺) and (Mg, Fe²⁺) + 2OH⁻ = Ti⁴⁺  + 2O²⁻ only. It is shown that incorporation of high-Cr concentrations (&gt; 5.5 wt % Cr₂O₃) is accompanied by an increase in the number of vacancies in the octahedral site with an increase in the proportion of the dioctahedral component K(Al, Cr, □)₂AlSi₃O₁₀(OH)₂.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00269-023-01232-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4418265","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":"Influence of octahedral site chemistry on the elastic properties of biotite","authors":"Dillon F. Hanlon,&nbsp;G. Todd Andrews,&nbsp;Roger A. Mason","doi":"10.1007/s00269-022-01230-5","DOIUrl":"10.1007/s00269-022-01230-5","url":null,"abstract":"<div><p>Brillouin light scattering spectroscopy was used along with detailed composition information obtained from electron probe microanalysis to study the influence of octahedral site chemistry on the elastic properties of natural biotite crystals. Elastic wave velocities for a range of directions in the <i>ac</i> and <i>bc</i> crystallographic planes were obtained for each crystal by application of the well-known Brillouin equation with refractive indices and phonon frequencies obtained from the Becke line test and spectral peak positions, respectively. In general, these velocities increase with decreasing iron content, approaching those of muscovite at low iron concentrations. Twelve of thirteen elastic constants for the full monoclinic symmetry were obtained for each crystal by fitting analytic expressions for the velocities as functions of propagation direction and elastic constants to corresponding experimental data, while the remaining constant was estimated under the approximation of hexagonal symmetry. Elastic constants <span>(C_{11})</span>, <span>(C_{22})</span>, and <span>(C_{66})</span> are comparable to those of muscovite and show little change with iron concentration due to the strong bonding within layers. In contrast, nearly all of the remaining constants show a pronounced dependence on iron content, a probable consequence of the weak interlayer bonding. Similar behaviour is displayed by the elastic stability, which exhibits a dramatic decrease with increasing iron content, and by the elastic anisotropy within the basal cleavage plane, which decreases as the amount of iron in the crystal is reduced. This systematic dependence on iron content of all measured elastic properties indicates that the elasticity of biotite is a function of octahedral site chemistry and provides a means to estimate the elastic constants and relative elastic stability of most natural biotite compositions if the iron or, equivalently, magnesium, concentration is known. Moreover, the good agreement between the elastic constants of Fe-poor (Mg-rich) biotite and those of phlogopite obtained from <i>first-principles</i> calculation based on density functional theory indicates that the latter approach may be of use in predicting the elastic properties of biotites.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4205902","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":"Single-crystal X-ray diffraction and IR-spectroscopy studies of potassium-deficient fluorapophyllite-(K)","authors":"Yurii V. Seryotkin,&nbsp;Igor N. Kupriyanov,&nbsp;Mark A. Ignatov","doi":"10.1007/s00269-022-01229-y","DOIUrl":"10.1007/s00269-022-01229-y","url":null,"abstract":"<div><p>Three samples of fluorapophyllite-(K) with different cation composition were studied by the X-ray diffraction and IR-spectroscopy methods. The samples (K_0.72(NH₄)_0.20)_Σ0.92Na_0.08 Ca₄[Al_0.04Si_7.96O₂₀]F·8H₂O from Nidym and K_0.87Na_0.06 Ca₄[Si₈O₂₀]F·8H₂O from Akhaltsykhe localities are characterized by the deficiency of large cations K⁺ and (NH₄)⁺ in the A site; the chemical composition of Talnakh sample (K_0.94(NH₄)_0.06)_Σ1.00 Ca₄[Si₈O₂₀]F·8H₂O is close to the stoichiometric one. The large cations deficiency in the structure of Nidym and Akhaltsykhe samples is compensated by the presence of medium-sized Na⁺ cations, located 1.12–1.31 Å away from the A position. The planar coordination of Na is formed by four H₂O molecules. The occurrence of ammonium ions is found for the Nidym and Talnakh samples and their concentrations are estimated from the IR spectra and structure refinement. Polarized infrared measurements performed for fluorapophyllite-(K) samples oriented along the <i>c</i>-axis reveal pleochroic behavior of the OH absorption bands. The observed pleochroism is explained in terms of absorption from two OH vectors of the H₂O molecules in the crystal structure.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2023-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4208168","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 variations of amorphous magnesium carbonate during nucleation, crystallization, and decomposition of nesquehonite MgCO3·3H2O","authors":"Gen-ichiro Yamamoto,&nbsp;Atsushi Kyono,&nbsp;Satoru Okada","doi":"10.1007/s00269-022-01231-4","DOIUrl":"10.1007/s00269-022-01231-4","url":null,"abstract":"<div><p>Carbonate minerals are major contributors to carbon sequestration in geological deposits; however, their nature and behavior remain unclear. Amorphous magnesium carbonate (AMC) is formed as a precursor to crystalline magnesium carbonates and as a product of thermal decomposition of nesquehonite (NSQ). In this study, the AMCs formed during the crystallization and decomposition of NSQ were investigated using X-ray diffraction (XRD) and atomic pair distribution function (PDF) methods. An AMC with a hydromagnesite-like structure (AMC-I) was formed immediately after mixing MgCl₂ and Na₂CO₃ solutions. After 5 min of stirring, no change was observed in the XRD pattern; however, the PDF pattern changed. This suggests that the medium-range ordered structure of AMC-I transformed into an intermediate structure (AMC-II) between AMC-I and NSQ. After 10 min of stirring, the AMC-II crystallized into NSQ. In the case of Rb₂CO₃, the AMC-II structure was formed immediately after the mixing of solutions and was stable for three days. AMC-II in the Rb₂CO₃ solution appeared to be in equilibrium with energetic local minima, indicating the existence of polyamorphism in AMC. When Cs₂CO₃ solution was used, the first precipitate had an AMC-I structure. By stirring for 5 min, the AMC-I was transformed to AMC-II, and after 10 min of stirring, a few quantities crystallized into NSQ. After three days, NSQ dissolved and transformed back into AMC-I. Thus, it is inferred that the crystallization of NSQ is significantly influenced by alkali cations in aqueous solutions. The AMC formed during the thermal decomposition also possesses the AMC-I structure.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5145461","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":"Pressure-induced phase transition of CO32−-bearing scapolite by in situ X-ray diffraction and vibrational spectroscopy","authors":"Cheng Qian,&nbsp;Yungui Liu,&nbsp;Xiang Li,&nbsp;Yudong Zhu,&nbsp;Haipeng Song,&nbsp;Xiang Wu","doi":"10.1007/s00269-022-01226-1","DOIUrl":"10.1007/s00269-022-01226-1","url":null,"abstract":"<div><p>Scapolite Na_2.25Ca_1.43K_0.30Fe_0.02[Al_4.23Si_7.77O₂₄]Cl_0.72(SO₄)_0.1(CO₃)_0.18 has been investigated by single-crystal X-ray diffraction, Infrared and Raman spectroscopy combined with diamond anvil cells (DAC) up to 19.6 GPa at room temperature, to understand its phase stability and the behaviors of CO₃²⁻. The experimental results show that a phase transition from the tetragonal phase (<i>P</i>4₂/<i>n</i>) to the triclinic phase occurs at 10.7 GPa, which is attributed to the pressure-induced rotation of tetrahedra around the bridging O atoms. The pressure–volume data were fitted to the second-order Birch–Murnaghan equation of state, yielding <i>V</i>₀ = 1102.6(8) ų and <i>K</i>₀ = 70.3(9) GPa for the tetragonal phase and <i>V</i>₀ = 1188.2(16) ų and <i>K</i>₀ = 33.0(3) GPa for the triclinic phase. In the triclinic phase, the larger compressibility is due to the increased degree of freedom in the crystal structure, and the anisotropy of the axial compressibility may be related to the ionic radius of the anionic group. From the Infrared absorption and Raman spectroscopy data, we speculate that CO₃²⁻ is extruded by the four-membered rings at the (001) plane during the whole pressure range. The high-pressure behavior of CO₃²⁻ in scapolite provides a possibility that carbon exists in the Earth’s interior as CO₃²⁻ coupled to silicates.</p></div>","PeriodicalId":20132,"journal":{"name":"Physics and Chemistry of Minerals","volume":"50 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4643920","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}