Ratio of Fe2+ vacancies of magnetite can be considered as an indicator of the low-temperature oxidation. In this study, to evaluate the low-temperature oxidation of magnetite from several localities and occurrences, the ratios of vacancies were estimated from powder X-ray diffraction studies using Guinier camera. Ratios of vacancies obtained from synthetic samples are almost consistent with reference samples. However vacancy ratios obtained from natural sample were not simply depend on their occurrences.

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We performed quantitative analyses of arsenic (As) in sheet silicates, particularly chlorite which are considered to add As to groundwater to estimate the extent of As contamination in Bangladesh. Using ICP-MS and AAS, total As concentrations in chlorite from Holocene sand layer (depth 23.6m) near Old Brahmaputra river and sand from Meghna river were measured to be 32.126 ppm and 36.913 ppm. Also using XAFS and HPLC/ICP-MS, trivalent and pentavalent As in chlorite from both locations were measured. Trivalent As was under detection limits. Pentavalent As was detected to be 31.692 ppm and 38.558 ppm. We can estimate that chlorite from both locations includes As and As contamination would be spread in sand layer of ground water aquifer near Old Brahmaputra river and surface near Meghna river.

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The interlayer structure of iron-rich chlorite after dehydroxylation by annealing in air has been investigated by powder XRD and high-resolution transmission electron microscopy (HRTEM). Fourier synthesis of the basal reflections indicated that the dehydroxylated interlayer consists of two atomic planes, as reported by Guggenheim et al. (1999) for clinochlore. The two atomic planes were also identified by the contrast in HRTEM. These results suggest that the dehydroxylated interlayer structure of iron-rich chlorite is basically identical with that in clinochlore.

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Komatsu et al.(2007a) synthesized delta-Al(OD)3 at 18 GPa and 973 K using a Kawai-type multi-anvil apparatus. Based on powder X-ray diffraction at ambient conditions, they showed that delta-Al(OD)3 is isostructural with delta-Al(OH)3 with space group Pnam, previously synthesized by Dachille and Gigl(1983) at high temperatures and high pressures. However, successive neutron diffraction measurements at ambient conditions(Komatsu et al., 2007b) revealed that the real space group of delta-Al(OD)3 is P212121, but not Pnam as obtained by X-ray diffraction experiments. Here we use ab initio calculations to study the structural and enegetic properties of delta-Al(OH)3, and their pressure dependence.

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The relationship between symmetry and hydrogen bond in the polymorphs of aluminum hydroxide will be discussed based on our recent results of x-ray and neutron diffraction studies.

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High-pressure single crystal X-ray diffraction experiments and ME analysis were conducted to estimate hydrogen position of super hydrous phase B. After structural parameters were refined except for hydrogen, unmeasurable reflections were calculated from the parameters. The electron distributions could be estimated by ME analysis with observed Fo and selected Fc.

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The high-pressure study of second-order phase transformation of silicon and tin dioxides has been performed by the diamond anvil cell experiments. In the case of tin dioxide, the second-order phase transformation was confirmed using the in situ Raman spectroscopy method. However, the uncertainty of this method to determine the phase boundary was significant because the change in Raman peaks on the phase transition was not clear. In the case of silicon dioxide, the phase boundary between the rutile-type and the CaCl2-type structure was determined by the synchrotron X-ray diffraction method. The dP/dT slope of this transformation determined in this study is smaller than that reported by previous work.

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Spin state of Fe3+ in Al-bearing post-Mg-perovskite was measured by X-ray emission spectroscopy by reducing pressure from 165 to 35 GPa at room temperature. The result indicates that Fe3+ is low spin from 165 to around 95 GPa and it becomes almost high spin from around 95 to 35 GPa. This indicates that most Fe3+ in Al-bearing post-Mg-perovskite in the lower mantle would be in the low spin state.

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It is accepted that a calcium ferrite phase is one of high-pressure constituent minerals of subducting oceanic crust at lower mantle conditions. Calcium ferrite-type CaAl2O4 is an endmember of the calcium ferrite phase. In this study, a high-pressure micro-Raman spectroscopy of the calcium ferrite-type CaAl2O4 was performed in the pressure range of 0-37 GPa at room temperature using a diamond anvil cell apparatus. Its thermodynamic Grüneisen parameter was determined to be 1.44 by averaging 26 of mode Grüneisen parameters which were derived from pressure dependence of lattice vibrational mode frequencies. Heat capacities at constant pressure calculated using the thermodynamic Grünesisen parameter are consistent with observed ones within the uncertainties. Also, it gives the thermal expansion coefficient of about 2.5x10^-5 1/K.

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Isobaric heat capacity of stishovite was measured at 2-311 K by thermal relaxation method, and standard entropy of stishivite was determiend as 24.0 JK-1mol-1. Combining the datum with standard entropy of coesite and the enthalpy of coesite-stishovite transition, the equilibrium coesite-stishovite transition boundary was calculated. The results indicate that the calculated boundary is placed very close to the boundary determined by high-pressure X-ray diffraction method, but that the calculated boundary has a slope larger than that by the high-pressure experiments.

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Inelastic x-ray scattering measurements at high pressure have been performed on the BL35XU beamline at SPring-8. We have measured the spectra of pure iron and the Fe_0.83Ni_0.09Si_0.08 alloy in diamond anvil cell from 50 GPa to 135 GPa at room temperature. Spectra were collected in the transmission geometry with the X-ray beam impinging on the sample through the diamonds along the compression axis of the pressure cell. Based on the spectra of the inelastic scattering, we calculated the sound velocity of the sample at high pressure. The sound velocity and the density of the alloy follow a linear relation, i.e., the Birch's law. The Vp-density (d) relation for Fe_0.83Ni_0.09Si_0.08 alloy can be expressed as Vp (m/sec) = 1.50(±0.17)d(kg/m2) - 6570(±1690) of which slope is steeper than that of pure iron.

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Syntheses of spinel were performed by flux method using Pt-crucible and electric furnace. Starting materials are as follows. The principal ingredients are MgO and Al2O3. The coloring reagent is Cr2O3 for red color. The fluxes are MoO3, PbO, and PbF2. The successful experiment was carried out by using the following conditions. The mole ratio of MgO/Al2O3 is 1/1, the weight ratio of (MgO+ Al2O3)/(PbO+PbF2) is 1/15, and the weight ratio of (MgO+ Al2O3)/Cr2O3 is 5/1. The maximum temperature was 1,100 and heating time was 6 days. The increasing ratio was 3.7/min and the decreasing ratio was 3.0/min. The product is reddish spinel. The crystals also show regular octahedron form and have 0.3 to 1.5 mm in size.

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High-pressure XRD on the structure of hydrous and anhydrous NaAlSi3O8 melt has been preformed up to 6.5 GPa. The intermediate range ordering, which consists of aluminous silicate network markedly shortened in the hydrous one, suggesting that water depolymerizes the network structure. However, the network structure for the hydrous one didn't show large shrinkage with pressure comparing to anhydrous one. In the radial distribution function, the evidence for the Al3+-coordination transformation was found at around 3 GPa in both melt. A degree of the change is more pronounced in the hydrous melt, which may be enhanced by the depolymerizing effect of water.

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High pressure and high temperature behaviors of Xe-Fe and Xe-Ni system have been studied using a laser-heated diamond anvil cell combined with synchrotron radiation X-ray diffraction. No new compound was found even at core pressure in Xe-Fe and Xe-Ni system, and no detectable amounts of dissolution of xenon was also found even in hcp iron up to 155 GPa.

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A series of laser-heated diamond anvil cell experiments using three types of low-crystalline carbon materials were conducted to test whether amorphous diamond can be obtained by static high pressure experiments. The results showed that low-crystalline carbon materials involving a considerable amount of modified sp2 bondings and relatively low heating temperature are essentially required for successful static high-pressure synthesis of amorphous diamond. The former provides preferential nucleation sites for diamond, resulting in explosive spontaneous nucleation and the latter plays a role in suppressing the subsequent grain growth to freeze the unique amorphous characteristics.

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A 6000-ton press multianvil apparatus was installed at Geodynamics Research Center, Ehime University, in 2009. Using this currently world-largest Kawai-type apparatus, we are now able to produce pressures to 15 GPa in sample volumes of greater than 1 cm3. Nano-polycrystalline diamond (NPD or HIME-DIA) of up to 8mm in both length and diameter has been successfully produced, and it is expected that this apparatus can be used for 1) high-quality polycrystalline sintered bodies, 2) single crystals, 3) large amounts of various high-pressure phases relevant to deep Earth mineralogy at pressures up to ~25-30GPa.

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The influence of pressure and temperature on the crystallographic preferred orientation of olivine aggregates was investigated via simple-shear deformation experiments at high pressures and temperatures (P = 2.1−7.6 GPa, T = 1493−1673 K) under dry conditions using a deformation-DIA apparatus. We found that the A-type fabric, which was developed by the (010)[100] slip system, was dominant at low pressures (≤ 5.2 GPa). At 7.6 GPa, B-type-like fabric (developed by the (010)[001] slip system) and B/C-type fabric (by the (hk0)[001] slip systems) were dominant at 1493 and 1673 K, respectively. These two temperature-dependent fabric transitions occurring at 7.6 GPa result in low seismic anisotropy with VSH/VSV (the ratio of horizontally and vertically polarized shear wave) > 1 at low temperatures (i.e., old-continental mantle conditions) and VSH/VSV < 1 at high temperatures (i.e., oceanic mantle conditions) at greater depths.

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Strength contrast between plagioclase and olivine was tested by two-phase deformation experiments at Moho conditions. Deformation microstructures indicate that both samples were plastically deformed via dislocation-controlled creep. Our experimental results show that olivine is weaker than plagioclase at T = 400°C, whereas plagioclase is weaker than olivine at T = 800°C. Consequently, strength contrast between plagioclase and olivine is sensitive to temperature, and olivine is weaker than plagioclase, or almost no difference of strength between these materials at the continental Moho conditions. This suggests that the "cremes brullee" model, in which the upper mantle is weak and the strength is limited to the crust, is expected as a rheological layer model of the water-rich Moho conditions.

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In order to clarify deformation mechanism of antigorite serpentine, we observed the microstructures of naturally deformed serpentinite mainly with transmission electron microscopy (TEM). The sample is an antigorite serpentinite collected from the Sashu Fault in the Saganoseki Peninsula of Oita Prefecture, which develops S and S-C fabrics. The antigorite grains composed of the serpentinite show the lattice preferred orientation (LPO) characterized by [010] and [001] density maximums subparallel to lineation and normal to foliation, respectively (Soda and Takagi, 2010). Our observation using TEM suggests that the antigorite grains were deformed plastically by the following two mechanisms: 1) (001) twinning and 2) migration of screw dislocations with (001) [010] slip system. The migration of this type of screw dislocations can form the LPO described above in antigorite serpentinite.

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Domains of disordered stacking were found out in minerals that were precipitated under metastable condition. The domain is important for nucleation and growth processes of the metastable mineral. TEM observations have been carried out about marcasite and showed that the domains exist in the crystal. We observed internal textures and defects of natural pyrite crystals that grew from low-temperature solution. In pyrite crystals, anti-phase domain boundary, dislocation and inclusion are common defects. Domains of disordered stacking were found out in only Kannnondo sample. HRTEM analyses show that basic structure of the domain of disordered stacking is marcasite. The Domain of disordered stacking is accentuated in marcasite.

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Photoluminescence (PL) spectroscopy and textural analyses were performed for two samples of natural polycrystalline diamonds, carbonados, from the Central African Republic. Theses samples revealed distinctly different PL spectral: sample-A is characterized by 3H center and absence of 575 nm N-V center whereas H3 center and 575 nm N-V center are evident in sample-B. The former and the latter are respectively typical of Group-A and Group-B of Kagi et al. (1994, 2007). Textural characteristics are also different between the two samples: for example, voids of ca. 1-10 microns are pervasively distributed in sample-A whereas voids are large and localized in sample-B. Based on these observations, we will discuss about timing and mechanism of irradiation of carbonados.

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Diamond in ureilites was first reported in 1888. The genesis of diamond in meteorites has been a problem of many years. The existence of compressed graphite associated with diamond reveals that diamonds in ureilites formed as a result of shock conversion of graphite. Mechanism of conversion from graphite to diamond has also been discussed based on high-pressure experiments and molecular dynamics. However, direct observation of diamond in ureilites suggesting conversion mechanism has not been done until now. In this study, we observed diamonds associated with graphite by a high resolution transmission electron microscopy (HRTEM).

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On the basis of microstructural observation particularly on the crystallographic relationships among minerals obtained by the use of EBSD, we consider the mechanism and reaction kinetics of the kelyphitization of garnet in peridotites. Kelyphitization of garnet starts to occur when garnet peridotite is decompressed in an ascending mantle. It initiates with a nucleation of Opx on the garnet/olivine interface. As Opx grows, spinel nucleates repeatedly at the margin of the growing Opx and at the adjacent to the olivine. The Mg- and Si-ion exchange must occur between the spinel forming sites and the Opx-replacing olivine site via grain boundary diffusion. We hypothesize that topotaxic or non-topotaxic relationships of spinel is established at the nucleation stage , which is inherited during a subsequent growth of the kelyphite.

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We conducted crystallization experiments in the system Ab–Qtz–H2O at 0.8 GPa. Fine euhedral Ab and Qtz crystals were formed in the runs with non-eutectic bulk compositions cooled below the liquidus temperature. Their texture was similar to equigranular granites. In the case of eutectic composition, graphic intergrowths of Ab–Qtz and coarse euhedral crystals in the cavities were formed, resulting in a large supercooling of the crystal-free melt and solution-precipitation processes via fluid phase, respectively. These textures mimic the zonation and miarolitic pegmatites.

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Crystalline silicates were found in circumstellar environments by comparing infrared spectra of astronomical observations and laboratory measurements. A precursor material for the crystalline silicates in circumstellar is considered to be amorphous silicates. In order to reveal the crystallization process of the amorphous silicates, we synthesized amorphous silicates with an enstatite and a forsterite composition in using the radio frequency thermal plasma processing. The amorphous samples were heated at 650-850C for 10min-240hr. We estimated the degree of crystallization using infrared spectral fittings of the samples. We evaluated a time constant of the crystallizationand a kinetic parameter, and estimated the activation energy of crystallization Ea. We made a T-T-T diagram from the results, and discussed on the time-dependent crystallization processes by comparison with previous experimental studies.

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Structural changes of GeO₂-SiO₂ glasses by mechanical milling have been investigated by using scanning electron microscopy (SEM), X-ray diffraction measurements (XRD) and infrared spectroscopy (IR). Reduction of the particle size of GeO₂-SiO₂ glass was observed up to 100h of milling. After 100h of milling, the particle size remained almost constant at about 1μm. IR spectra of these glass may indicated the reduction of Ge-O-Ge angles. This variation may be attributed an increase of the 3 and 4 membered rings of GeO₄ and SiO₄ tetrahedrons in the structures. This result is consistent with that of IR spectra. With increasing of milling time, a new diffraction peak at about 2θ= 8°was observed. This new peak may be attributed to the second order structure of 3 and 4 membered rings of GeO₄ and SiO₄.

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Distribution of Fe³⁺ and Ga³⁺ among octahedral and tetrahedral sites in synthetic (CaFe³⁺GaSiO₆)₉₀(CaGa₂SiO₆)₁₀-clinopyroxene (FeGaTs90GaTs10-Cpx) was investigated to evaluate a relation between site occupancies of trivalent cations in the octahedral and tetrahedral sites and ionic sizes of trivalent cations. The FeGaTs90GaTs10-Cpx was synthesized from glass starting material at 1200C in air. The site occupancies of Fe and Ga and crystal structure were refined using Rietveld method. The resulting site populations at the octahedral M1 and tetrahedral T sites was [Fe³⁺0.67(1)Ga0.33]M1[Si1.0Fe³⁺0.23Ga0.77]T. This result is nearly consistent with that by Mössbauer analysis, Fe³⁺M1:Fe³⁺T=0.59:0.32, after Akasaka et al. (1997).

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Thermo Gravimetry (TG) measurements during the dehydration reaction of Ca(OH)₂ and Ca(OD)₂ at several heating rates. Activation energies of their dehydration reaction were estimated by using the isoconversion method proposed by Ozawa (1965) and isotope effects on dehydration kinetics of portlandite will be discussed.

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We have started on the growth of anorthite(CaAl₂Si₂O₈) crystal by using the flux of CaO-V₂O₅ with Li₂O and/or B₂O₃ additive. In the Li₂O flux, the crystal of ca. 10x5x2 mm was obtained, whereas crystals of several millimeters were obtained in the other flux . Thus grown crystals of anorthite, however, were mostly translucent or colored in pale yellow or gray, and were often cracked or polycrystalline. Nevertheless, the transparent single crystals and the single crystalline domains, of 1-2 millimeters were also obtained. By the preliminary XRD any significant shift of peak was not detected for both flux systems.

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Montmorillonite (MT) is a rare mineral with which crystal structure analyses has not yet been achieved, though it is a very familiar mineral. Its single crystallization was tried using a high purity MT powder prepared by Keizo Suzuki (Hokkaido Univ.). After holding the MT (25-75wt%H2O) at 5.5GPa and 1700 °C for 1 hour, it processed by various cooling processes. The recovered samples were observed by OM. SEM and XRD. A part of them was investigated by the X-ray single crystal oscillation method. By quenching (〜1000 °C/min) from 1700 °C, MT crystals in the form of needle and in irregular forms were obtained. However, MT might not be stable even at low temperature, since it decomposed into the anhydrous silicates by slow cooling and by re-heating (>400 °C) after quenching to the room temperature. The present results suggest an availability to obtain MT single crystals for an X-ray sutructure analysis.

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We present here results of high pressure experiments in the Fe-C system at 5GPa, 1200 to 1500 C. We have observed Fe3C, Fe7C3 and graphtie as stable phases in the run products. Based on the results obtained, we speculate the amount of carbon presentin the core.

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We performed X-ray Raman scattering spectroscopy (XRS) at the magnesium and silicon L edges on MgSiO3 glass under high pressure conditions. Local structures have been estimated from the electronic structure obtained by XRS. The results show that local structure around silicon seems to change around 17 GPa.

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The filled ice Ic structure of hydrogen hydrate shows the high-pressure stability, and this stability was considered to be induced by intermolecular interactions. In this study, high pressure experiments of deuterated hydrogen hydrate were performed. Then, the intermolecular interactions in the filled ice Ic structure were examined. High-pressure experiments revealed that the replacement of hydrogen atoms occurred in the filled ice Ic structure between host framework water molecules and guest hydrogen molecules. Also, the O-D vaibrational mode in the host D2O molecules was clearly changed at around 40 GPa. This change was considered to be induced by the symmetrization of hydrogen bond for host water molecules

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Tektite is natural glass and formed as large meteorites at the Earth's surface. Local structure of Fe in tektite was studied by X-ray absorption fine structure (XAFS) spectroscopy. We have carried out Fe K-edge XAFS measurements to get information about the local structure and chemical state of Fe in many species with different locality, size and color in tektites such as Hainanite, Indochinite, Philippinite, Australite, Bediasite and Moldavite. This study indicates that the local structure of Fe should be changed in the impact event and the following stage. Local structure of Fe should be related with the temperature, pressure, quenching rate, sizes of impact meteorite and size of falling melts. As a result, there are some difference in the bonding structure of Fe atoms and arrangements of neighboring oxygen.

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Ti k-edge X-ray absorption near edge structure (XANES) spectra of PbTiO3 and various titanates such as ATiO3 (perovskite- and ilmenite-type structure, A=Mg,Ca,Sr,Ba,Pb) and A2TiO4 (spinel-type structure, A=Mg,Fe) were measured at various temperatures up to 1100 K. The composition, local structure and temperature dependence of XANES spectra was investigated especially on the phase transition. Ti k-edge XANES spectra change largely with different compositions, while the temperature dependence of XANES spectra is small in the each compound even if undergoing structural phase transition. Perovskite-type ATiO3 compounds reveal several phase transitions. Weak but distinct changing of the XANES spectra was observed near phase transition point. Five pre-edge peaks can be identified: pp(a) 4.9667eV, pp(b) 4.9687eV, pp(c) 4.9727eV, pp(d) 4.9747eV and pp(e) 4.9796eV.

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Ti K-edge X-ray absorption near edge structure (XANES) spectra of BaTiO3, SrTiO3 perovskite and TiO2 rutile and anatase were measured at various temperatures. The composition, structure and temperature dependence of XANES spectra was investigated especially on the phase transition.The XANES spectra for TiO2 are largely different between anatase and rutile structure.SrTiO3 and BaTiO3 perovskite undergo several structural phase transitions in the temperature ranges in this study, SrTiO3; rhombohedral-tetragonal-cubic, BaTiO3; trigonal-orthorhombic-tetragonal-cubic, the distinct changing of pre-edge XANES spectra was observed near transition points. These structural transitions of perovskite are caused mainly by rotation and distortion of TiO6 octahedron. Five pre-edge peaks can be identified: pp(a) 4.9667eV, pp(b) 4.9687eV, pp(c) 4.9727eV, pp(d) 4.9747eV and pp(e) 4.9796eV. The temperature dependence for each pre-edge peak is largely different in temperature and local structure.

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X-ray single-crystal structure analyses were performed on vanadinite, Pb5(VO4)3Cl from Mibladen, Morocco, at room temperature, and the results were compared with previous ones on vanadinite and pyromorphite. EPMA analysis showed that the present specimen had no impurity. No sign of superstructure was found on X-ray photographs. The crystallographic space group was P63/m and the cell dimensions were 10.317(1) A for the a axis and 7.337(1) A for the c axis. The results of the present study clearly indicated that the VO4 tetrahedron behaved as a rigid body in the vanadinite structure. An amount of atomic displacements at Cl site, locating at an anion channel along the c axis, are larger along the c axis direction than in the other directions. This can be attributable to the larger size of the void in the Pb(2)3 regular triangle at z = 1/4.

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Pyrope is a major constituent of the earth's upper mantle. Mg in pyrope occupies the dodecahedral site, although it seems to occupy the octahedral site according to Pauling's first rule. This anomalous coordination environment is reminiscent of the possibility of Mg static disorder together with its large thermal vibration. Indeed, it is well known that the displacement parameter of Mg in pyrope is much larger than those of dodecahedral cations in other silicate garnets. However, conclusive evidence for the presence of the Mg static disorder has not yet obtained. To solve this problem, we conduct the structure analyses of a synthetic pyrope at 20 temperature-points over the wide temperature range of 96.7-972.9 K using single crystal X-ray diffraction. We examine the temperature dependence of the mean square displacements of atoms and the electron density distributions around the Mg site at low temperature.

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FZ-grown rutile (TiO2) normally shows blue coloration. This has been ascribed to d-d transition at Ti3+ due to oxide-ion deficiency. Our TG measurements on as-grown blue rutile (up to 800C in air) showed that the specimen changed its color from blue to white associated with weight-loss of around 0.3%. Determined cell dimensions on four-circle diffractometer showed that there was no difference among blue (as grown) and pale-yellow (calcined in air) specimens (a = 4.5937(4) A, c = 2.9585(2) A). Furthermore, structure refinement showed a sign of lower oxide-ion content on pale-yellow one than that in blue one. The cause of different colors for blue and pale-yellow crystals should be ascribed to difference in characters of color-center and not to an amount of oxide-ion deficiency.

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Algorithms and weighting methods for MEM analysis of X-ray and neutron diffraction data are evaluated by using simulation data. While electron densities calculated by the 0th-order single pixel approximation (ZSPA) and the Cambridge algorithm are mostly consistent with each other, small deviation of the ZSPA solution from the real maximum entropy condition was observed. Such deviation was sometimes pronounced when using structure factors of reflections with small inter planar distances d. For analysis of X-ray diffraction data, a proper weighing for estimated standard deviation of observed structure factors were found to be necessary. For analysis of neutron diffraction data, on the other hand, large weighting, such as those based on d values, were found to be inappropriate.

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High-temperature synchrotron X-ray powder diffraction experiments for sillimanite have been carried out in the present study to clarify the stability field of mullite by drawing TTT-diagram of mullitization. Our results show that mullite have stability fields above approximately 1150 C at atmospheric pressure.

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We conducted transformation experiments in the garnet lherzoltite stability field (3.2 GPa and 1000-1200°C for 1-20 hours) with a spinel single crystal embedded into powder mixture of orthopyroxene and clinopyroxene in order to study the kinetics of this reaction. As results, the garnet reaction rim was formed between single crystalline spinel and polycrystalline pyroxenes. The kinetics of the reaction rim growth was analysed based on the diffusion-controlled growth mechanism.

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Pyroxene is one of the major constituent minerals in the Earthʼs crust and upper mantle. Enstatite (Mg2Si2O6) is an end-member of orthopyroxene and known to have five polymorphs at atmospheric pressure; low-temperature orthopyroxene (LT-Opx; space group: Pbca), low-temperature clinopyroxene (LT-Cpx; space group: P21/c), high-temperature orthopyroxene (HT-Opx; space group: Pbca), high-temperature clinopyroxene (HT-Cpx; space group:C2/c) and protopyroxene (Ppx; space group: Pbcn). Their phase relationships are complex. The aim in present study is to clear the relationships by studying the transition temperature between LT- and HT-Opx and between LT- and HT-Cpx

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Thermal expansion of forsterite (Mg2SiO4), corundum (Al2O3) and Pt were measured by in-situ high-temperature X-ray diffraction method up to 1450C using the furnace attached to the multiple-detector system installed at the BL-4B2 experimental station of the Photon Factory (PF), High Energy Accelerator Research Organization (KEK), Japan. The cell parameters were refined by the Rietveld method using a computer program RIETAN-FP. The refined unit-cell parameters was precise, a=3.92317(1) Å for Pt, a=4.75854(2) Å and c=12.98992(5) Å for corundum, and a=10.19566(2) Å, b=5.98085(1) Å, and c=4.75486(1) Å for forsterite, respectively, where the error bar represents the estimated standard deviation in the Rietveld analysis.

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Potasium niobate crystal fibers have been successfully grown from stoichiometric composition melt by μ-PD method. Most effective factor may be low temperature gradient to grow KNbO₃ fiber. Characterization results of grown fibers are discussed.

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The investigation of the two type vacancy defect energies in periclase (MgO); one is uncoupled cation and anion vacancies which is called as Schottky vacancies of cation and anion and another is the coupled cation-anion vacancy, is reported be a density functional theory (DFT) calculation. Schottky vacancy energy was corrected for the defect-defect interaction. Although the corrected Schottky vacancy energy is smaller than the coupled Mg-O vacancy defect energy in small cell, in large cell the coupled Mg-O vacancy defect energy has smallest value. This suggests that periclase within the coupled Mg-O vacancy is more stable than within uncoupled Mg & O Schottky vacancy at low temperature. At high temperature, on the other hand, periclase within uncoupled Schottky vacancy may be more stable than that within the coupled vacancy because the configurational entropy of vacancies in the former system is larger than the latter system.

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Light path that penetrated a coccolith was analyzed by using simulated software.Coccolith have an inward curved shape,for example Florisphaera Sp. ,the light path bend to inside.

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We will discuss on the magma evolution of an A-type granite of Cape Ashizuri Ring Complex from zircon internal textures. The zircons have three anomalous internal textures and we call them RD, LD and HD on this study. Both RD and LD have low Y2O3 and UO2, and they would originate in resorption-precipitation and local recrystallization, respectively. HD has very high concentration of HfO2 and Low concentrations of Y2O3 and ThO2, in despite of same UO2 with igneous texture, and that gives the low Th/U ratio below 0.1. The igneous texture has low HfO2 and UO2 in core and high those impurities in rim and they divided by RD. By SEM observation we obtained the texture formation sequence of (1) igneous or hydrothermal core, (2) LD1, (3) RD, (4) igneous rim, (5) LD2, and (6) igneous rim and crystal surface. And then we will be discussing the transition of growth environments of zircon based on the formation and chemical features of the anomalous textures.

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Structural characterization and crystal size of carbonaceous materials in Gyoja-yama contact metamorphic region were closely and comparatively examined by Raman micro-spectroscopy, XRD and HRTEM. Characteristic features about grain sizes and morphologies were found. Using these characteristics, we discuss about new geothermometer tools.

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Ore minerals and mineralization stages of the Chaarat gold-bearing antimony deposit,Middle Tien-Shan, Kyrgyzstan Kenzhebaev Kubat, and Masahide Akasaka Department of Geoscience, Graduate School of Science and Engineering, Shimane University, Matsue, Japan Corresponding author:ikubich@yahoo.com. The gold-bearing Chaarat deposit is located at the Chatkal district of the Jalal-Abad region, Kyrgyz Republic. Chatkal valleys considers have a numerous placers and ore occurrences and deposits . The Chaarat deposit is one of these occurrences, but it has not been studied in detail yet. The aim of study is to define the physical and chemical conditions, and the stages of mineralization.

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