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Laser beam micromachining was applied to super-hard nano-polycrystalline diamond (NPD) synthesized by the direct conversion of graphite at high pressure and high temperature. Three types of pulsed lasers were tested: nanosecond near-infrared, nanosecond near-ultraviolet, and femtosecond near-infrared lasers. The latter two were also applied for synthetic single crystal of diamond to compare the results with those of the NPD. It was demonstrated that the nanosecond near-infrared laser was the most efficient device for rough shaping of the NPD, while the ultraviolet and femtosecond lasers give satisfactory results for precise surface finishing of it. The properties of the laser-processed surfaces were analyzed by scanning and transmission electron microscopy, laser scanning microscopy, and micro Raman spectroscopy. These analyses demonstrated that the three types of lasers play different and complementary roles, and that their combination is the best suitable solution for micromachining of the hardest diamond into any desired shapes.

Rudist specimens of Late Albian age from the Upper Chickabally Mudstone Member of the Budden Canyon Formation, Great Valley Sequence, in northern California, are identified as a canaliculate rudist taxon based on shell morphology and mineralogy. Since they are incomplete right valves without cardinal and myophoral parts, their systematic placement is difficult, though their canal characters are similar to those of relatively derived caprinuloidinid rudists such as Texicaprina and Jalpania (Caprinidae) of the Caribbean/Gulf region. Re-assessement of the holotype specimen of Durania? californica from the Upper Albian of northern California reveals that it does not belong to the Radiolitidae, but is also a canaliculate rudist. The distribution of canaliculate rudists, probably caprinuloidinids, in the midlatitudes of the Northeast Pacific suggest that this area belonged to the Tethyan Realm at that time, and a faunal connection existed between the Northeast Pacific and the Caribbean and/or the Central Pacific at least in the Late Albian.

We have conducted laser processing of ultrahard nano-polycrystalline and single crystalline diamonds (NPD, SCD, respectively) using nano-pulsed near-ultraviolet laser, and the machining properties were compared through microstructural examinations by SEM, TEM and Raman spectroscopy. The cut depth of the laser-cut grooves was observed to be deeper for the NPD than for the SCD. This is probably due to the lower thermal conductivity feature of NPD, which provides higher absorption efficiency of the laser energy and decreases the laser ablation threshold. TEM cross-section observation showed that the processed grooves in the both types of diamonds are covered with identical laser-modified layers (~ 1 µm thick) composed of roughly oriented nanocrystalline graphite. A marked difference was observed between the laser-processed surfaces of NPD and SCD: in the former the diamond–graphite interface is almost linear and undamaged, whereas in the latter the boundary is slightly folded and significantly distorted. These textural features suggest that different laser-machining processes are involved between NPD and SCD in the microscopic scale. Our results demonstrate that pulsed laser can be used even more effectively for the fabrication of nano-polycrystalline diamond than the case for single crystal diamond.

Experimental distribution coefficients of rare earth elements (REEs) between Fe oxyhydroxides (FeOOH) and Mn dioxide (δ-MnO2) and solutions [ K D(REE)] exhibit anomalous variations: preferential uptake of light REEs by Mn dioxide, a step-like trend in K D(REE) in the Er-Tm-Yb-Lu region, and fractionation of K D(Y) from K D(Ho). Extended X-ray absorption fine structure (EXAFS) spectroscopy was applied to determine coordination states of Er, Tm, Yb, Lu, and Y adsorbed onto FeOOH and δ-MnO2 to assess structural changes around the REE site. The structures obtained, combined with previously determined structures of light REEs-sorbed Fe and Mn samples, corresponded to variations found in K D(REE). The structural parameters in the first coordination sphere suggest that La, Pr, and Nd adsorbed onto δ-MnO2 have a distorted tenfold-coordination sphere and differ greatly from La-, Pr-, Nd-, and Sm-sorbed FeOOH, which have a mixture of eightfold- and ninefold-coordination spheres. In contrast, heavy REEs including Y adsorbed onto Fe and Mn samples’ local structures have an eightfold-coordination sphere. The preferential uptakes of light REEs by δ-MnO2 are explained by the structural change. The irregular variations of heavy REEs and Y fractionation from Ho in K D(REE) do not, however, correspond to any change found in the coordination sphere. During characterization of the first coordination sphere, the W-type tetrad effect appears in the series variation of interatomic distances of REEaq3+ and REE-sorbed FeOOH and δ-MnO2. The occurrence of a tetrad effect indicates that the interatomic distances relate not only to the electrostatic field but also to a quantum field.

Coordination states of rare earth elements (REEs) adsorbed by iron oxyhydroxide (FeOOH) and manganese dioxide (δ-MnO 2 ) (REE = La, Pr, Nd, and Sm) were determined using extended X-ray absorption fine structure (EXAFS) spectroscopy. Multi-electron excitation, resulting in double-electron excitation (2p, 4d → 5d, 5d) for REE-L III edge EXAFS spectra, possibly causes a considerable error in EXAFS analyses for light REEs. To obtain reliable structural parameters this study elucidates the effects of double-electron excitation on the local structure determination of light REEs on poorly crystallized FeOOH and δ-MnO 2 . For this study, anomalous features attributable to excitation are superimposed on EXAFS signals of La, Pr, Nd, and Sm samples in the 5.0-7.0 A -1 k range. The relative intensity of the double-electron excitation to the L III adsorption edge is

金沢大学理工研究域自然システム学系, Based on both major and trace element chemistry, the occurrence of the intergranular component in mantle-derived xenoliths from far eastern Russia has been constrained. Whole-rock trace element measurements of one xenolith show apparent negative anomalies in Ce, Th, and high field strength elements on normalized trace element patterns. The trace element pattern of the whole rock differs from those of constituent minerals, indicating that the anomalies in the whole rock are attributable to the presence of an intergranular component. That assumption was confirmed using in situ analysis of trace elements in the intergranular substance and melt inclusion using laser ablation inductively coupled plasma-mass spectrometry. Both the intergranular component and the melt inclusions have identical trace element patterns, which mean that these materials are a cognate metasomatizing agent. The anomalies are regarded as mantle metasomatism related to an aqueous fluid. Hydrous minerals were observed on the wall of the melt inclusions using micro-Raman spectroscopy, indicating that the melt inclusions contained a large amount of water. Thus, this study reveals a trace element composition of a hydrous metasomatizing agent in the mantle. © 2009 The Authors Journal compilation © 2009 Blackwell Publishing Asia Pty Ltd.

The design of an elliptical neutron guide for the time-of-flight (TOF) powder diffractometer of the high-pressure material science beamline at J-PARC was optimized using the McStas Monte Carlo simulation program to increase neutron flux for a small sample size. We investigated the analytical design in accordance with some requirements such as the gain factor at the small sample size and sufficient resolution at shorter wavelength of incident neutrons. The intensity and divergence with respect to energy dependence for elliptical guide designs were compared with those for the linearly tapered and straight guides. Optimizing the design of the elliptical guide results in the largest gain below 0.70 A wavelength and gives constant instrumental resolution greater than 1 A. The guide can support a flux gain of about 2.2 (high-intensity mode, Δ d / d of ca. 0.6%) and 1.2 (high-resolution mode; Δ d / d of ca. 0.5%) greater than 1 A compared to the beamline of the natural flight path with resolution similar to that provided by the optimized elliptical guide.

Scanning near-field optical microscopy (SNOM) technique was applied to nanometer-scale residual stress mapping for directionally solidified Al 2 O 3 /monochromic ZrO 2 and Al 2 0 3 /cubic ZrO 2 (Y 2 O 3 ) eutectics, which are ranked as candidates for high-strength materials at high temperatures, These eutectic composites were grown using the micro pulling down (μ-PD) method with a radio frequency heating system. Topographic images and fluorescence spectra of those eutectic composites were measured simultaneously for each pixel on a sample. Its peak intensity, peak position, and peak width, which, respectively, correspond to the abundance of Al 2 O 3 , stress in the grain, and the anisotropy of that stress, were estimated for each fluorescence spectrum. The distribution of residual stress was observed on a sample surface with spatial resolution of 300 nm; the spatial resolution was constrained by the optical fiber aperture size. Tensile stress was observed in Al 2 O 3 of Al 2 O 3 /mZrO 2 and compressive stress was observed in Al 2 O 3 of Al 2 O 3 /cZrO 2 . The stress distributions were visualized within a single Al 2 O 3 grain. Considerable stress anisotropy was detected in the grain boundary between Al 2 O 3 and ZrO 2 for both eutectics.

A new type of scintillator crystal, Ce-doped Gd 9.33 (SiO 4 ) 6 O 2 (Ce:GSAP), was grown by the micro-pulling-down (μ-PD) method. Single-crystal structural analysis coupled with X-ray absorption near-edge structure (XANES) analysis clearly implied the preference of Ce 3+ at the 6h site in the Ce:GSAP structure. The X-ray excited luminescence spectra showed a peak around 410 nm originating from the Ce 3+ 5d–4f transition. The corresponding decay time estimated was about 25 ns.

We measured the Raman spectra of Fe-Mg olivine grains with Mg# [= 100 × Mg/(Mg + Fe)] values ranging from 80-100 under a pressure of up to 4 GPa using a diamond anvil cell (DAC). We focused on a relatively weak peak at around 547 cm-1, denoted as peak 0, and two intense peaks at around 825 cm-1 (peak 1) and 857 cm-1 (peak 2). The peak position (κ) of each peak shifted upward linearly as Mg# and pressure increased; the Mg# derivatives (∂κ/∂Mg#) for peak 0, peak 1, and peak 2 under ambient pressure were 0.496, 0.184, and 0.227 cm-1/Mg#, respectively. The pressure derivatives (∂κ/∂P) for peak 0, peak 1, and peak 2 were 1.558-2.08, 3.38-3.46, and 3.20-3.35 cm-1/GPa, respectively. The value of ∂κ/∂P for peak 0 decreased as Mg# increased, whereas those for peak 1 and peak 2 were almost constant against Mg#. The peak positions of peak 0, peak 1, and peak 2 were formulated as functions of Mg# and pressure based on the results. We found that when the ranges of Mg# and pressure are limited to 85-100 and 0-1 GPa, the combination of peak 0 and peak 1 reproduced the original observed data with an error of ± 0.9 for Mg# and an error of ± 0.09 GPa for residual pressure. We applied these functions to a natural olivine inclusion in a diamond obtained from Internationalnaya pipe, Yakutia, Siberia, Russia, and obtained reasonable values of Mg# and pressure—91.6 ± 0.6 Mg# and 0.32 ± 0.05 GPa, respectively.

A three-dimensional (3D) Raman mapping system with a real-time calibration function was developed for detecting stress distributions in solid materials from subtle frequency shifts in Raman spectra. An atomic emission line of neon at 918.3 cm−1 when excited at 514.5 nm was used as a wavenumber standard. An emission spectrum of neon and a Raman spectrum from a sample were introduced into a single polychromator using a bifurcated optical fiber. These two spectra were recorded simultaneously on a charge-coupled device (CCD) detector using double-track mode. Energy deviation induced by the fluctuation of laboratory temperature, etc., was removed effectively using the neon emission line. High stability during long measurements was achieved. By applying curve fitting, positions of the Raman line were determined with precision of about 0.05 cm−1. The present system was applied to measurements of residual pressure around mineral inclusions in a natural diamond: 3D stress mapping was achieved.

A method was proposed for measuring infrared absorption spectra at high pressure under quasi-hydrostatic pressure conditions. Two KBr micro-pellets were prepared as samples, and reference materials were charged in a diamond anvil cell, applying helium as the pressure-transmitting medium. Using this method, the quasi-hydrostatic pressure condition was retained up to approximately 20 GPa. Furthermore, hydrostaticity was much better than conventional pressure-transmitting media used for infrared spectroscopy. Infrared absorption spectra of α -FeOOH at high pressure were measured using the KBr micro-pellet method with a helium pressure-transmitting medium. Downshift of the OH stretching vibration was observed with increasing pressure. Use of the KBr micro-pellet method for infrared absorption spectroscopy at high pressure is a complementary experimental technique to neutron diffraction at high pressure for studying the pressure response of hydrogen bonds.

Micro-Raman spectroscopy enables precise non-destructive analyses of CO 2 density in a very small volume. By applying this method to CO 2 fluid inclusions in minerals, a contrast is apparent in the CO 2 density specific to mineral species in a mantle-derived spinel lherzolite xenolith entrained by ascending magma. The rock investigated in this study comprises four mineral species: olivine, orthopyroxene (opx), clinopyroxene (cpx), and chromianspinel (spinel). The CO 2 densities in the fluid inclusions in these minerals are 1.006–1.035, 1.148–1.154, 1.150–1.154 and 1.189–1.194 g/cm 3 , respectively. During transport of the rock by magma and subsequent cooling, the CO 2 fluid inclusions change their volume due to both elastic and plastic properties of the host mineral, which are sensitive to differential pressure between internal pressure of the CO 2 fluid inclusion, and stress in surrounding crystal lattice. We tested the possibility that the volume of CO 2 fluid inclusion changes by the differential pressure. Existing models dealing with the volume change of fluid inclusion in response to deformation of host mineral do not explain the density gradation, particularly that between pyroxenes and spinel. We propose that combination of precise determination of fluid density in mantle-derived minerals and observation of microstructure in the host mineral provides a deep insight into the deformation mechanism of natural minerals under high differential pressure and temperature.

We have made a detailed study of the extended X-ray absorption fine spectra (EXAFS) at the K edge of aqueous Y ion and at L 3 edges of aqueous lanthanide ions and thereby elucidated the systematic changes in their hydration structures. Anomalous peaks arising from double-electron excitation (2 p , 4 d → 5 d , 5 d ) appear in the EXAFS signals of La 3+ -Tb 3+ between 5–7 A −1 . We established a removal process of double-electron excitation from EXAFS spectra. Using that process, we confirmed that the intensity and energy position of the extracted double-electron excitation are comparable to previously reported data. The presence of double-electron excitation engenders a smaller error than the errors estimated in the fitting process. Consequently, double-electron excitation does not seriously affect the determination of the structures of REE 3+ aquo ions in the first coordination sphere. Subsequent EXAFS analyses of hydrated REE 3+ ions suggest that the hydration numbers, the interatomic distances, and the Debye-Waller factors decrease from 9.7, 2.55 A, and 9.0 × 10 −3 A 2 for La 3+ to 7.9, 2.31 A, and 5.7 × 10 −3 A 2 for Lu 3+ . These parameters change as a sigmoid curve with increasing atomic number. The hydration structures of REE 3+ ions are inferred to change from the nonahydrated structure for La 3+ -Nd 3+ to the octahydrated structure for Tb 3+ -Lu 3+ through intermediate structures for Sm 3+ , Eu 3+ , and Gd 3+ . In addition, the hydration state of Y 3+ closely resembles that of Ho 3+ because the two have almost identical ionic radii.

Carbonado diamonds from the Central African Republic (CAR) were investigated using spectroscopic observations. Raman spectra for a polished section of carbonado showed the average Raman frequency as 1333.0 cm −1 ; measurements 10 μm below the sample surface showed a bimodal distribution of the Raman frequency with the average at 1333.5 cm −1 . These contrasting results indicate that the carbonado interior retains considerable residual pressure. The maximum residual pressure detected in this study from the 10 μm subsurface was 0.49 GPa. From infrared (IR) absorption spectra for crushed carbonado samples, no absorption attributable to diamond was observed because absorption bands of mineral and fluid inclusions were too strongly observed. Acid leaching treatment of the crushed grains elicited IR bands assignable to intrinsic diamond vibration and nitrogen impurity in the diamonds. Nitrogen atoms in the CAR carbonado were not much aggregated and the degree of aggregation was intermediate between type Ib and type IaA. In the chemically treated samples, IR absorption bands from liquid water and carbonate were ubiquitous suggesting that the CAR carbonado samples contain fluid inclusions and are similar to diamonds containing mantle-derived fluids. The experimental results of this study suggest that the CAR carbonado originated from rapid heating event with a presence of fluid in the mantle and subsequent rapid cooling before aggregation of nitrogen impurity in the diamond lattice.

The changes in pressure ( P ) and temperature ( T ) conditions experienced by a natural diamond, as it rises to shallower depths and is eventually erupted at the Earth’s surface, give rise to stresses between the diamond and any inclusions it contains as a consequence of their differing changes in volume cell parameters in response to P and T . In the case of diamonds with lower-mantle silicate inclusions such effects will be markedly enhanced by phase transformations by which MgSi-perovskite and CaSi-perovskite transform to pyroxene, pyroxenoid and other phases. Using micro-Raman and SEM-EBSD techniques, we have carried out investigations of the diamond immediately adjacent to inclusions with lower mantle perovskite chemical compositions, and compared them with studies of lower-mantle ferropericlase and upper-mantle inclusions. In the Raman studies evidence of shifts in frequency and width in the diamond Raman spectral band at 1333 cm−1 were sought and found to be greater for perovskite than ferropericlase. However, even for MgSi-perovskite the effects only indicated stored residual pressures of ca 0.35 GPa, which have also been found for typical upper mantle inclusions. The EBSD studies showed a marked contrast between diamond adjacent to former perovskite (now transformed to pyroxene and other phases) and ferropericlase. EBSD mapping shows lattice distortions in diamond adjacent to former MgSi-perovskite and CaSi-perovskite of 4 to 7°; but adjacent to ferropericlase the distortion was only 1–2°. The results show that the large strain changes accompanying decompression and phase transformation of the perovskite inclusions were largely accommodated by plastic strain within the diamonds at high temperatures, and only small residual pressures were retained in the diamonds.

Using in situ strength measurements at pressures up to 10 GPa and at room temperature, 400, 600, and 700°C, we examined rheological properties of olivine, orthopyroxene, and chromian-spinel contained in a mantle-derived xenolith. Mineral strengths were estimated using widths of X-ray diffraction peaks as a function of pressure, temperature, and time. Differential stresses of all minerals increase with increasing pressure, but they decrease with increasing temperature because of elastic strain on compression and stress relaxation during heating. During compression at room temperature, all minerals deform plastically at differential stress of 4–6 GPa. During subsequent heating, thermally induced yielding is observed in olivine at 600°C. Neither orthopyroxene nor spinel shows complete stress relaxation, but both retain some stress even at 700°C. The strength of the minerals decreases in the order of chromian-spinel ≈ orthopyroxene > olivine for these conditions. This order of strength is consistent with the residual pressure of fluid inclusions in mantle xenoliths.

Chromium K-edge X-ray absorption near-edge structure (XANES) spectra of natural ferropericlase were measured using an X-ray microbeam from a synchrotron radiation source to estimate the valence state of Cr. Measured samples were inclusions collected from lower-mantle diamonds. The obtained results revealed that divalent chromium is present in the materials in the lower mantle and that the proportion of Cr2+ in the total Cr content varied among the samples. The valence state of chromium in the inclusions in diamonds is a potential indicator of the redox conditions in the lower mantle.

The crystal structure of deuterated topaz [topaz-OD; Al2SiO4(OD)2], synthesized at 10 GPa and 800 °C, has been determined using neutron powder diffraction at pressures up to 7.5 GPa. The linear axial compressibilities obtained from regressions of the lattice constants vs. pressure are βa = 1.87(1) × 10 –3 GPa –1 , βb = 1.71(1) × 10 –3 GPa –1 , and βc = 2.73(1) × 10 –3 GPa –1 . The occupancy of the D1 site was found to be greater than that of D2, as shown independently using neutron diffraction and infrared spectra at ambient conditions. A bifurcated hydrogen bond involving the D1 site, O4-D1···O2 and O4D1···O3, and a trifurcated hydrogen bond involving D2 site, O4-D2···O1, O4-D2···O2, and O4-D2···O4 are proposed for hydrogen-bond donor and acceptor pairs in addition to those reported previously. The observed pressure dependences of the hydrogen-bonding geometry show that these donor and acceptor pairs are classifiable into two types of interaction: (1) those that strengthen as a function of pressure (O4-D1···O3, O4-D2···O2, and O4-D2···O4) and (2) those that weaken (O4-D1···O1 and O4-D2···O1). These results also demonstrate that the reason for the contrasting behavior of the ν(OH) between F-rich natural topaz and topaz-OH are both the cooperative effect, O4-D2···O4-D1···O3, and the increasing Al-O4 distance.

Effects of pressure on the physical properties are very important for understanding highly correlated electron systems, in which pressure-induced attractive phenomena such as superconductivity and magnetically ordered non-Fermi liquid have been observed. Up to now, many scientists have developed a lot of high pressure apparatus for each purpose. In this paper, we present the very small “palm cubic-anvil high-pressure apparatus” for precise electric transport measurements under high pressure up to 8 GPa. The most outstanding characteristic of this pressure cell is its compactness. This cell enables us to measure absolute values of electrical resistivity, magneto-resistance and Hall coefficient at various temperatures. The details of our palm cubic high-pressure apparatus are introduced, and some neutron experimental results at room temperature are discussed.

Akazara scallop striated adductor muscle troponin C (TnC) binds only one Ca2+ because the three EF-hand motifs are short of critical residues for the coordination of Ca2+. Fourier-transform infrared spectroscopy was applied to study coordination structures of M2+ (= Mg2+, Ca2+, Sr2+, and Ba2+) bound in an Akazara scallop TnC mutant (E142D) and the wild-type TnC C-lobe in D2O solution. The region of the COO− antisymmetric stretch provides information regarding the coordination modes of a COO− group to a metal ion. The side chain COO− group of Asp142 did not bind to Ca2+ in the bidentate coordination mode, suggesting that the absence of a methylene group is critical for the Ca2+ coordination structure of Akazara scallop TnC (Nara et al., Vib Spect 2006, 42, 188–191). The present study has shown that the absence of a methylene group is not compensated for by a larger metal ion such as Sr2+ or Ba2+. CD spectra showed that the secondary structures are conserved between M2+-free (apo), Mg2+-loaded, Ca2+-loaded, Sr2+-loaded, and Ba2+-loaded states, which was consistent with the results estimated from their amide I band patterns. The metal-ligand interaction at position 12 of site IV is discussed in comparison with the coordination mode of the side chain COO− group of the wild-type TnC C-lobe. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 595–599, 2008. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

In this article, we overview the applications of neutron diffraction at high pressure to earth and planetary sciences. One of the main targets of mineralogy is to determine hydrogen position in hydrous minerals. Structures of hydrogen-bearing minerals and silicate melt at high pressure will contribute to understanding relationship between water and deep earth processes. Neutron is also a powerful tool to distinguish isoelectronic ions in minerals. To achieve these new scientific applications, we are going to construct a beamline dedicating to earth and planetary sciences at high pressure in J-PARC. The preliminary design of the beamline will be introduced.

The high-pressure and high-temperature material science beamline has been approved for the construction in J-PARC. We are going to install two types of high-pressure devices in the beamline. One is a large volume multi anvil device for the generation of high temperature and high pressure up to 2000 K and 15 GPa. The other one is an opposed sintered diamond anvils for generating pressures higher than 30 GPa. The outline of the beamline and recent progress are introduced in this review article.

Stishovite is an important phase in subducting oceanic crust. The post-garnet assemblage from a precursor eclogite lithology contains up to 25% stishovite at pressures above 25 GPa. This stishovite may contain up to 5 wt.% Al 2 O 3 . We measured the hydrogen contents of stishovite samples synthesized at 20–25 GPa and 1200–1800 °C from several starting materials containing up to 10 wt.% Al 2 O 3 . FTIR spectra of stishovite show major bands at 3111–3134 cm − 1 , with the frequencies increasing as H 2 O and Al 2 O 3 contents increase, and several minor bands at 2659–2667, 3240, 3261, 3312–3334, and 3351 cm − 1 . The H 2 O content of Al-free stishovite is in the range of 16–30 wt. ppm. The maximum H 2 O content of Al-bearing stishovite (4.4 wt.% Al 2 O 3 ) synthesized at 20 GPa and 1400 °C is 3010 ± 300 wt. ppm. Most hydrogen in stishovite is associated with Al 3+ substitutional defects on the octahedral (Si 4+ ) site. The hydrogen can occupy 40% of vacancies created by incorporation of Al 3+ at 20 GPa. This observation along with some anomalies in the FTIR spectra may indicate an alternative mechanism of Al 3+ incorporation into stishovite via the formation of oxygen vacancies or interstitial Al i defects. We report the highest H 2 O concentrations in Al-stishovite to date, and argue that it is the most important carrier of water into the lower mantle post-garnet eclogitic assemblages.

Monoclinic and triclinic high-pressure phases of KHCO 3 were identified using in situ high-pressure single-crystal X-ray analysis. These monoclinic and triclinic phases, designated as phases IV and V, respectively, differ from three previously identified phases: I–III. The lattices of the two phases are superimposed along a IV * = 2 × a V * and hk 0 and h 0 l nets of both phases lie on the same plane, i.e., the (100) plane is common in both lattices in real space. The space group of phase IV is P 2 1 / b 11 with lattice constants of a = 10.024(3) A, b = 6.912(5) A, c = 4.1868(11) A, α = 115.92(4)°, and V = 260.9(2) A 3 . The crystal structure of phase IV, excluding the hydrogen atoms, was successfully determined by direct methods and is isostructural with a cesium hydrogen carbonate CsHCO 3 .

A change in the linear pressure behavior of the chrysotile Raman O-H band is revealed by an in-situ high-pressure Raman study using a diamond anvil cell (DAC) at 0.1–0.4 GPa pressure intervals. The peak of 3701 cm −1 can be accurately determined in the pressure range of 0.2–4.5 GPa regardless of peak fitting models. The pressure ( P )-wavenumber (ν) relationship for the peak is closely approximated by two linear functions with the slopes (dν/d P ) of 4.3 cm −1 /GPa and 1.7 cm −1 /GPa at pressures above and below 1.7 GPa, respectively. The spectral resolution given by a peak fitting method (0.5 cm −1 ) implies that these functions for changes in the positions of the 3701 cm −1 peak provide pressure estimates with resolutions of 0.1–0.2 GPa. This method can be used to estimate remnant pressure in natural samples in the form of thin sections. The pressure shift characterized by the change in slope and the associated decrease of the peak width can be explained by a model where the change in compressibility of the tetrahedral layer affects the interaction between the inner O-H and Si atoms forming a six-membered ring. The high-pressure dependence at pressures lower than 1.7 GPa may be a contribution of a dominant layer-parallel (in-plane) compression that compensates a distortion in the tetrahedral layer of chrysotile. The conclusion that chrysotile changes its compressibility at around 1.7 GPa is significant for understanding of the properties of chrysotile nano-fibers and possibly for thermodynamic consideration on serpentine phase relations.

The bulk major- and trace-element compositions of micro-inclusions in 24 cuboid diamonds from the Udachnaya kimberlite pipe (Siberia, Russia) have been quantitatively analyzed by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LAM-ICPMS). Micro-inclusions in the studied diamonds represent a bulk sample of the fluids from which the diamonds crystallized; they define a continuous range between magnesian and calcic carbonate-rich compositions at relatively constant Fe contents (Ca/(Ca + Mg) = 0.31–0.68; Mg/(Mg + Fe) = 0.66–0.78). In general the major- and trace-element patterns of the trapped fluids in Udachnaya cuboid diamonds are similar to those of kimberlites and carbonatites. However, some important differences are observed: (1) the fluids in diamonds are enriched in K, Na, Fe and depleted in Al relative to the host kimberlite; (2) the REE patterns of the fluids are steeper than those of kimberlites; (3) many of the fluids show strong depletion in Ti, Zr and Y. The observed geochemical features are consistent with a genetic link between the diamond-forming fluids and ephemeral carbonatitic fluids/melts which may be precursors of the host kimberlite. These fluids/melts may originate either from the metasomatic and influx of carbonatitic agents or from partial melting of previously carbonated eclogites and peridotites. Some elemental variations may be explained by fractional crystallization of such fluid/melts, or mixing between fluids with different compositions.

The density, and therefore the pressure, of CO2 fluid inclusions in minerals can be estimated from the Fermi diad splitting of Raman spectra of CO2. An accurate determination of the pressure of CO2 fluid inclusions enables the estimation of the depth origin of rocks from the deep Earth. A micro-Raman densimeter was applied to ultramafic–mafic xenoliths sampled along the Ohku coast of Oki-Dogo Island in the Sea of Japan (East Sea). The density of CO2 fluid inclusions in the mafic granulite was 1.02–1.05 g/cm3, while those of lherzolites were 0.98–1.02 g/cm3. In contrast, the density of CO2 fluid inclusions measured in olivine gabbro, clinopyroxenite, and harzburgite were lower ranging from 0.86–to 0.99 g/cm3. Taking into account the temperature condition estimated using a pyroxene thermometer, the mafic granulite originated from a depth of 27–30 km and the lherzolites from 25–29 km. The overlapping depth of 27–29 km can be interpreted as the depth including the Moho discontinuity under Oki-Dogo Island 3.3 Ma. This estimation is consistent with geophysical observations.

Carbonado diamonds from the Central African Republic were investigated using spectroscopic observations and C-isotopic analysis. Based on photoluminescence (PL) spectra, carbonado samples were classified into two groups: Group-A, which exhibits an intense PL band at 504 nm; and Group-B, which exhibits PL bands at 504, 575, and 638 nm at room temperature. PL spectra measured at 120 K gave well-resolved side-band structures of 504 nm bands. Consequently, the 504 nm band of Group-A can be assigned to the 3H center attributable to self interstitials in diamond, whereas the 504 nm band from Group-B can be assigned to the H3 center attributable to a vacancy (□) trapped at nearest-neighbor substitutional nitrogen (N) pairs. The PL band at 575 nm, which is attributable to neutral N-□ pairs, is known to increase its width with increasing residual stress in diamond aggregates. The average FWHM of the 575 nm band and the standard deviations were 3.80 and 0.54 nm for Group-A carbonado, and 2.80 and 0.38 nm for Group-B carbonado. These values suggest that Group-A carbonado samples have higher residual stress than the Group-B samples. The presence of an H3 center and the lower residual stress in Group-B carbonado both suggest that they originated from higher temperatures compared to Group-A. Radiation halos were observed in cathodoluminescence (CL) images of both Group-A and Group-B samples. The CL halos are traces of radiation damage from radioactive nuclides. The texture of the haloes suggests that the radiation damage was a secondary event after formation of the carbonado diamonds. The average C-isotopic composition of Group-A is -23.6 ± 0.52‰ in δ 13 C PDB and that of Group-B is -26.3 ± 0.65%o. Group-A carbonado was enriched systematically in 13 C compared with Group-B carbonado. Isotopic fractionation might occur as a result of the different thermal history of carbonado.

Neutron is a complementary probe to X-ray for material sciences at high pressure, especially for hydrogen compounds for which X-ray is less powerful than for the heavier elements. In addition, using the neutron probe it is easy to distinguish neighboring elements in the periodic table which is also difficult with X-ray. A spallation neutron source of new generation is now being constructed in Tokai, Ibaraki Pref. as a part of the J-PARC project. A proposal to build a dedicated high-pressure beamline at J-PARC was submitted, which has been successfully accepted in 2005 after the peer-review. In this article, we review some examples of scientific targets on material sciences of hydrogen compounds at high pressure, which will be newly revealed with this powerful neutron source and beamline.

The high-pressure phase of gibbsite has been studied byin situsingle crystal X-ray diffraction method and molecular dynamics (MD) simulation at 3.0 GPa. The crystal structure of the high-pressure phase,η-Al(OH)3, was successfully determined by direct methods based on the intensities of X-ray diffraction. The space group and lattice constants forη-Al(OH)3areP21/b11 (#14),a= 8.612(3) Å,b= 5.013(2) Å,c= 9.194(5) Å andα= 90.34(6)°, respectively. The crystal structure ofη-Al(OH)3consists of an Al octahedral layer, and the layers are connected via H-bonds. The mechanism of the phase transition from gibbsite toη-Al(OH)3is also discussed in the context of previously reported powder X-ray diffraction data.

Fourier-transform infrared spectroscopy (FT-IR) was applied to study the coordination structure of Ca 2+ bound in Akazara scallop troponin C (TnC) and its site-directed mutant possessing inactivated Site IV (E142D mutant) in D 2 O solution. The COO − antisymmetric stretching region provides information about the coordination modes of a COO − group to a metal ion. The wild type exhibits a band at 1543 cm −1 in the Ca 2+ -bound state, indicating that the side-chain COO − group of Glu142 (the position 12 of Site IV) serves as the ligand for Ca 2+ in the bidentate coordination mode [F. Yumoto, M. Nara, H. Kagi, W. Iwasaki, T. Ojima, K. Nishita, K. Nagata, M. Tanokura, Eur. J. Biochem. 268 (2001) 6284–6290]. However, the E142D mutant showed no band around 1543 cm −1 in the Ca 2+ -loaded state, indicating that the side-chain COO − group of Asp142 does not bind to Ca 2+ in the bidentate coordination mode. This result suggests that the absence of a methylene group is critical for the Ca 2+ coordination structure of Akazara scallop TnC. The Ca 2+ -ligand interaction at Site IV is discussed in comparison with the results of synthetic peptide analogues of Site IV of Akazara scallop TnC.

We verified the performance of a conventional Raman spectrometer, which is composed of a 30 cm single polychromator, a Si based charge-coupled device (CCD) camera, and a holographic supernotch filter. For that purpose, the time change of the peak positions of Raman spectra of naphthalene and fluorescence spectra of ruby (Cr-doped Al2O3) were monitored continually. A time-dependent deviation composed of two components was observed: a monotonous drift up to 0.4 cm−1 and a periodic oscillation with a range of 0.15 cm−1. The former component was stabilized at approximately 2000 s after the CCD detector was cooled, indicating that incomplete refrigeration of the CCD detector induced the drift. The latter component synchronized with the periodic oscillation of the room temperature, indicating that thermal expansion or contraction of the whole apparatus induced this oscillation. The implemental deviation is reduced when measurements are conducted using a sufficiently cooled CCD detector at a constant room temperature. Moreover, the effect of the room temperature oscillation is lowered in a spectrum acquired over a duration that is longer than one cycle of this oscillation. Applying the least squares fitting method to carefully measured spectra enhanced the precision of the determination of the peak position to 0.05 cm−1 using the spectrometer with pixel resolution of 1.5 cm−1.

We constructed a scanning near-field optical microscope (SNOM) on a commercially available atomic force microscopy (AFM) apparatus (SPM-9500J2; Shimadzu Corp.) to measure the stress distribution in ceramic composite materials. Features of our SNOM system are: (1) a compact SNOM head substituted for the original AFM head; (2) a wide scanning range (125 × 125 μm2) inherited from the original scanner; (3) use of conventional shear-force regulation; (4) an optical system for the illumination-collection (I-C) mode; (5) excitation by a 488 nm line of an Ar-ion laser, and (6) light detection by photon counting or a polychromator equipped with an electronically cooled charge coupled device (CCD). This SNOM system was used to measure the surface structure and stress distribution of an Al2O3/ZrO2 eutectic composite. We simultaneously measured topographic images and fluorescence spectra of an Al2O3/ZrO2 eutectic composite. We estimated its peak intensity, peak position, and peak width from the fluorescence spectrum during scanning, which respectively correspond to the abundance of Al2O3, stress in the grain, and the anisotropy of that stress. Mapping images showed that the stress and its anisotropy were weaker in the center of the Al2O3 grain than its boundary between Al2O3 and ZrO2. That observation suggests that Al2O3 underwent intense anisotropic stress induced by volume expansion in the phase transition of ZrO2 from the cubic phase to the monoclinic phase during preparation.

Since the 8th century, more than seventeen eruptions have been recorded for the Mt. Fuji volcano, with the most recent eruption occurring in 1707 (Hoei eruption). For the past 300 years the volcano has been in a quiescent stage and, since the early 1960s, has exhibited neither fumarolic nor thermal activity. However, the number of low-frequency earthquakes with a hypocentral depth of 10–20 km increased significantly beneath the northeastern flank of Mt. Fuji in 2000–2001, suggesting a possible resumption of magmatic activity. In this study, diffuse CO2 efflux and thermal surveys were carried out in four areas of the volcano in 2001–2002 in order to detect possible signs of the upward movement of deep magma. At all survey points, the CO2 efflux was below the detection limit with the exception of a few points with biological CO2 emission, and ground temperatures at a depth of 20–30 cm were below ambient, indicating no surface manifestations of gas or heat emission. Should magma rise into the subsurface, the diffuse CO2 efflux would be expected to increase, particularly along the tectonically weakened lineation on the Mt. Fuji volcano, allowing for the early detection of pre-eruptive degassing.

Water-related features were studied using infrared absorption spectroscopy in fibrous diamonds with micro-inclusions. Both OH-stretching and HOH-bending vibrations were observed. The lack of correlation between the intensities of HOH and OH bands in different samples and the complexity of the OH-stretching band indicate that a large fraction of water is present as hydroxyl groups in minerals.Heating and cooling experiments were performed to elucidate the properties of fluids in micro-inclusions in diamonds. The results of experiments at various temperatures support the presence of several water-related components in individual diamonds. These spectroscopic investigations of fibrous diamonds revealed two or more interrelated water-related components preserved in micro-inclusions. The existence of several water phases or water solutions with different salinity and solutes within one diamond crystal is possible.

The coordination structures of Ca2+ ion bound to synthetic peptide analogues of the calcium-binding site III of rabbit skeletal muscle troponin C (TnC) were investigated by Fourier transform infrared (FTIR) spectroscopy. The region of the COO− antisymmetric stretching vibration provides information about the coordination modes of a COO− group to a metal ion. The 34-residue peptide corresponding to the EF hand motif (helix–loop–helix) showed a band at 1552 cm−1 in the Ca2+-loaded state, indicating that the side-chain COO− group of Glu at the 12th position serves as a ligand for Ca2+ in the bidentate coordination mode. On the other hand, the 13-residue peptide (Ac-DRDADGYIDAEEL-NH2) containing the Ca2+-binding site III (DRDADGYIDAEE) did not show such spectral patterns in the Ca2+-loaded state, meaning that shorter synthetic peptide corresponding to the site III has less or no affinity for Ca2+. It was found that the 17-residue peptide (Ac-DRDADGYIDAEELAEIF-NH2) is the minimum peptide necessary for the interaction of side-chain COO−of Glu at the 12th position with Ca2+ in the bidentate coordination mode. We discuss the relationship between the amino acid length of synthetic peptide analogues and the formation of Ca2+-bound coordination structure. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 339–343, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com

Variations of the chemical composition and elemental speciation of aeolian dust transported from China to Japan were investigated in this study. During 6‐12 April 2002, a large-scale dust event was observed in China, Korea, and Japan. Aerosol samples collected in Beijing, Fukuoka, Nagoya, and Tsukuba at that time were used for this study. Variations of most elemental concentrations against the particle size showed similar trends to that of Al concentration. The particle size distributions indicate that myriad elements in the aerosols originated mainly from mineral aerosols. The metal/Al concentration ratios showed little difference in chemical compositions for aerosols sampled at Beijing and Japanese stations: the chemical composition of aeolian dust is conserved during transportation. Examination by X-ray absorption near-edge structure (XANES) spectroscopy revealed that the Fe(III)/Total Fe (T-Fe) ratios of the aerosols collected in Beijing and Fukuoka were mutually resemblant, indicating that the oxidation-reduction reaction of Fe in aeolian dust during its transportation is negligible. However, their ratios were much higher than those of China loess and simulated Asian mineral dust (Chinese geo-reference materials: CJ-1 and CJ-2). Because the aerosol grain size is much smaller than those of CJ-1 and CJ-2, the fine mineral was transported selectively by wind from top soils. It was easily oxidized and had a high Fe(III)/TFe ratio. The XANES spectra of Mn in the aerosol indicated that the Mn(III)/Total Mn (T-Mn) ratios of the aerosol collected in Fukuoka were smaller than those of the dust collected in Beijing. The ratios of the aerosols in Beijing resembled those of CJ-1 and CJ-2. Moreover, only medium grains of the aerosol in Fukuoka had high Mn(III). The other grains had an almost identical Mn(III)/T-Mn ratio as the aerosol collected in Fukuoka in the no event. Thereby, most medium grain aerosols collected in Fukuoka comprised aeolian dust coming from China with high Mn(III)/T-Mn ratios like those of CJ-1 and CJ-2, but the other grain aerosols mixed greatly with local aerosols having low Mn(III)/T-Mn ratios. On the other hand, some elements such as Zn and Pb had different Al concentration ratios from Mn and Fe. The Zn/Al and Pb/Al concentration ratios of fine grains increased tenfold to a hundredfold with the decrease of particle size. Therefore, the increasing trend for these elements indicates that the fraction of anthropogenic materials was greatly increased in fine grains. The XANES spectra of Zn suggested that the contribution of mineral aerosols decreased gradually with decreasing particle size and that the residual components were explained by Zn(NO 3 ) 2 in coarse-medium grains and ZnSO 4 in fine grains. However, Zn in aeolian dust, which is a main component of mineral aerosols, only rarely originated from anthropogenic materials when a large-scale dust event was observed.

The crystal structure of a single crystal of synthetic hydrous forsterite, (Mg1.985Si0.993H0.06O4), synthesized at T = 1300 °C and P = 13.5 GPa has been investigated using X-ray diffractometry and unpolarized infrared absorption spectroscopy. The data show an Mg atom occupancy of 98.6(2)% at the M(1) site and 99.9(2)% at the M(2) site, indicating that the cation vacancies predominantly occur at the M(1) site. A comparison of the calculated bond distances shows that the most probable H atom locations are at the O(2) and O(3) sites, where H may be located in association with the vacancy at the M(1) or the T site, forming hydrogen bonds between two oxygen pairs, O(3)-O(1) and O(2)-O(1), which correspond to the OH stretching vibrations at 3566 cm−1 and 3612 cm−1 observed in the IR spectra.

Photoluminescence and Raman spectra with high spatial resolution (< 1 μm) were observed on a natural polycrystalline diamond, carbonado. The studied sample is from Central African Republic (CAR) and was polished to optical grade. In addition to observation by optical microscopy, Scanning Near-field Optical Microscopy (SNOM) was applied for spectral and topographic analysis at high spatial resolution less than 300 nm. Mapping of the photoluminescence intensity of carbonado using SNOM indicated that the emission intensity was lower at the grain boundaries and the fringe of pores of carbonado revealed weakest intensity. Photoluminescence spectra of carbonado observed using optical microscopy and SNOM comprised three sharp bands at 504, 575 and 638 nm with their side bands and the color of photoluminescence changed according to its location. Raman spectra measured using optical microscopy revealed that the residual stress locally exists underneath the sample surface and the maximum stress value observed in this study was 0.72 GPa. Additionally, pressure dependence of the 575 nm band was measured using a diamond anvil cell up to 3.5 GPa. The 575 nm band shifted linearly to a lower wavelength with increasing pressure with a gradient of - 0.57 GPa/nm. This relationship was applied to estimations of the stress distribution of carbonados using SNOM. No significant changes in peak positions of photoluminescence spectra were detected on the surface of carbonados. This result suggests that carbonado is well sintered and that the residual stress of carbonado exists locally inside the crystal.

Graphite from deposits occurring in the high-grade metamorphic rocks and their larteritized equivalents of the Thodupuzha-Kanjirappally Belt in Madurai Granulite Block, southern India is structurally fully ordered (crystallite size, Lc(002) ranging from 469 to 749 A), possess high degree of graphitization (DG value ranging from 105 to 267 A) and reflect crystallization at high temperature (700±100°C). Raman spectra of graphite display profiles corresponding to high crystallinity and high structural ordering. The high temperature crystallinity characteristics of graphite were not obliterated during retrogression of granulites to amphibolite facies gneisses. Preliminary carbon stable isotope results show a spread in isotope values from —11.8 to —26.8 %, which suggest more than one sources for carbon. The lighter carbon isotope values are suggestive of biogenic origin, whereas the heavier ones are probably fluid precipitated graphite.

Pressure responses of hydrogen bonding interactions were compared between potassium hydrogen carbonate (KHCO3) and sodium hydrogen carbonate (NaHCO3). KHCO3 undergoes a pressure-induced structural change at 2.8 GPa and room temperature whereas no phase transition has been found so far for NaHCO3 up to 11 GPa. KHCO3 exhibits a substantial decrease in the O-H O angle with increasing pressure. This change could be a trigger for the phase transition at 2.8 GPa. By contrast, no significant change in O-H O angle was observed for NaHCO3 up to 7 GPa. Based on the observations using neutron diffraction, X-ray diffraction and vibrational spectroscopy at high pressure, a possible mechanism for the phase transition of KHCO3 is suggested. In addition, the phase boundary of KHCO3 caused by the pressure-induced transition was determined using in situ Raman spectroscopy at high pressure.

Mid-infrared absorption spectra for all types of carbonaceous chondrites were obtained in this study to establish a versatile method for spectroscopic classification of carbonaceous chondrites. Infrared spectra were measured using a conventional KBr pellet method and diamond press method. Spectra of hydrous carbonaceous chondrites exhibit intense O-H stretching vibrations. CI chondrites are identifiable by a characteristic sharp absorption band appearing at 3685 cm^(-1), which is mainly attributable to serpentine. X-ray diffraction analysis showed the presence of serpentine. However, Yamato (Y-) 82162 (C1) does not have the band at 3685 cm^(-1) because of its thermal metamorphism. CM and CR chondrites have an intense absorption band at approximately 3600 cm^(-1). This absorption tends to appear in CM chondrites more strongly than CR chondrites because the intensity ratios of an OH stretching mode at 3520 cm^(-1) compared to 3400 cm^(-1) for CM chondrites are in the range of 0.95-1.04, which is systematically higher than those of CR chondrites (0.86-0.88). Therefore, the two types of chondrites are distinguishable by their respective infrared spectra. The spectrum feature of the Tagish Lake meteorite is attributable to neither CI nor CM chondrites. CO chondrites are characterized by weak and broad absorption at 3400 cm^(-1). CV chondrites have weak or negligible absorption of water. CK chondrites also have no water-induced absorption. CH and CB chondrites have a sharp absorption at 3692 cm^(-1) indicating the presence of chrysotile, which is also supported by observations of X-ray diffraction and TEM. The combination of spectroscopic classification and the diamond press method allows classification of carbonaceous chondrites of very valuable samples with small quantities. As one example, carbonaceous chondrite clasts in brecciated meteorites were classified using our technique. Infrared spectra for a fragment of carbonaceous clasts (

OH stretching vibration modes for F-rich natural topaz (F-topaz) and for fully hydrated topaz (topaz-OH) synthesized at high pressure, were observed using IR and Raman spectroscopies at pressures up to 30.4 GPa and 17.3 GPa, respectively. In F-topaz, the pressure derivative of the frequency of the OH stretching band observed at 3650 cm ' at ambient pressure was 0.91(3) cm - 1 /GPa, which was consistent with the value recently reported by Bradbury and Williams (2003). On the other hand, in topaz-OH, the pressure derivatives of the bands initially at 3599 and 3522 cm - 1 were -5.2(2) and -2.56(6) cm - 1 /GPa, respectively. This contrasting behavior between the two forms of topaz at high pressures suggests that the OH substitution for F in topaz affects the hydrogen-bonding behavior under high pressure.

Fluid inclusions in mantle-derived minerals can serve as a messenger from the deep Earth. If CO2 is a dominant phase of the fluid, the relationship between intensity ratio and frequency separation of the Fermi diad bands in the Raman spectra of CO2 can be used for determination of density of the inclusions. The intensity ratio and the frequency separation between the peaks thereby increase with density of CO2. Kawakami et al . (2003) have established the relationship between density of CO2 and the frequency separation of the Fermi diad bands using the Raman data on CO2 fluid with densities from 0.1 to 1.21 g/cm3, including super critical fluids at 58-59°C. Thus, micro-Raman spectroscopic analysis allows us to reveal multiple densities of the small fluid inclusions by one-by-one density analysis. Generally, inclusions show CO2 densities (pressure) specific to the individual host minerals in the order of spinel > orthopyroxene ∼ clinopyroxene » olivine. The density of CO2 reflects how strong host minerals are to withstand the pressure differential between the inclusion’s internal pressure and the external environmental pressure during transport of xenoliths to near the Earth's surface. Olivine underwent considerable plastic deformation resulting in the density reduction of CO2 fluid inclusions. On the other hand, the slightly higher density of CO2 in spinel can be explained by elastic deformation of the minerals during ascent and cooling of the xenoliths. Conversely, the density of CO2 inclusions in pyroxene will work as a useful geobarometer requisite for discussions on the origin of mantle-derived minerals.

We have developed a confocal fluorescence microscope for observation of the dissolution kinetics at various crystal faces under varying conditions. Natural calcite (CaCO3) was chosen for the experimental samples and the dissolution kinetics was estimated from the increase in the pH value of the solution using a fluorescent pH indicator, seminaphthorhodafluors-1. Using this instrument, we investigated not only the difference in dissolution rate among various crystal faces but also the effects of the surface roughness, subsurface structure (such as lattice defects) and inhibitor on the dissolution rate. Among the (1 0 1 4) , (1 0 1 0) and (2 1 3 4) faces of calcite samples, the (1 0 1 4) face dissolved most slowly and the (1 0 1 0) face fastest. Increasing the surface area of (1 0 1 4) face in contact with water by scratching increased the dissolution rate. Introduction of lattice defects on the (1 0 1 4) face by He+ irradiation significantly increased the dissolution rate. Inhibition of the calcite dissolution by La3+ occurred in the order of (1 0 1 4) > (1 0 1 0) > (2 1 3 4) .

Young (6 Ma) alkali-basalts were collected from the toe of the oceanward slope of the northern Japan Trench. Two types of olivine are present in these lavas, xenocrysts with reaction rims and magmatic. The forsterite (Fo) (no. 91–92) values and NiO contents (0.3–0.5 wt%) of the xenocrysts are similar in composition to those of the depleted mantle peridotite. The groundmass olivines have relatively lower Fo values (no. 81–88) and NiO contents (0.1–0.5 wt%). Reaction rims and the vicinity of the silicate inclusion in xenocrysts show the intermediate compositions between the xenocryst and magmatic olivines. Chromian spinel inclusions in the xenocrysts also show the depleted composition in the range of abyssal peridotite. CO2 fluid inclusions in the xenocryst records pressures before entrainment into the host magma up to 0.4 GPa, which corresponds to a depth of up to 14 km of lithospheric mantle. These data indicate that the xenocrysts originate from MORB-depleted mantle.

Impurity effects of trace lanthanum ion (La 3+ ) on the dissolution and growth of calcium carbonate were studied with in situ observation techniques. Dissolution kinetics of two polymorphs of calcium carbonate, calcite and vaterite, were investigated by monitoring the pH in the solution with laser-induced fluorescence spectroscopy using a pH-sensitive reagent, seminaphthorhodafluors. No effect on dissolution of vaterite was observed with the spectroscopic observations, whereas calcite dissolution was significantly inhibited by lanthanum ion with concentrations higher than 1 μM. Crystal growth and dissolution processes of calcite under the lanthanum-doped condition were observed by means of atomic force microscopy. Step propagations during crystal growth and dissolution of calcite were inhibited by trace lanthanum ion (5 μM). An insoluble thin layer of lanthanum carbonate deposited on the step site of the calcite surface could be a possible cause of the inhibitions observed both for dissolution and growth.

Micro-inclusions (1 –10 μm) in 55 diamonds of cubic habit from the Udachnaya kimberlite pipe have been studied using vibrational spectroscopy. This has revealed a multiphase assemblage in cuboid diamonds from the Udachnaya kimberlite pipe. This assemblage includes carbonates, olivine, apatite, graphite, water and silicate glasses. The micro-inclusions preserve the high internal pressure and give confidence that the original materials were trapped during growth of the host diamond. The internal pressures, extrapolated to mantle temperatures, lie within the stability field of diamond and the relatively low temperatures are typical for the formation of cuboid diamonds. In contrast to previously reported data for African diamonds, the micro-inclusions in the cuboids from Udachnaya are extremely carbonatitic in composition (H2O/(H2O+CO2) ≈5 –20%) with the observed assemblage of microinclusions similar to some types of carbonatites. The low water and silica content testify that the material in the micro-inclusions of the Udachnaya diamonds was near-solidus carbonatitic melt. Vibrational spectroscopy has provided the evidence of carbonatitic melts in cuboid diamonds.