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Morphology of well-ordered kaolinite (Keokuk, Iowa) crystals has been analyzed by using the high-resolution SEM and EBSD technique. Elongated hexagonal crystals always show the a-axis parallel to the elongated direction. The side-facets of these crystals are in parallel to the c-axis that is inclined by about 15° from the normal of the basal plane. In other word, the miller indices of the side-facets are exactly ±(110), ±(1-10) and ±(010). A facet indexed as ±(1-30) is occasionally developed. These morphological features must be reflected in the ordered stacking sequences (the position of the octahedral vacancy site and the direction of the interlayer shift) in the kaolinite crystals. Inversely, crystallinity of individual kaolinite grains may be evaluated from their morphology in a SEM.

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The dissolution mechanism of smectite under alkaline conditions has not been understood, because no in-situ AFM observations of smectite dissolution under alkaline conditions have been reported. In this study, we examined the dissolution behavior of single crystallites of smectite under alkaline conditions from 25C to 50C, using in-situ AFM analysis. The main goal of this work is to determine reactive surface area and to derive reliable dissolution rates of smectite under alkaline conditions.

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High frequency electrolysis was used for reducing calcium contained in circulation water as making calcium carbonate around the electrodes. In this test, we measured ORP, pH and chemical composition change during the scaling the calcium carbonate. Ca composition of fluid decreased under reduction condition and the decreasing rate of Ca depends on pH. Then, pH decreased from 8 to 5 and after pH reached around 5, Ca did not react to HCO3.

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Behavior of rare earth elements in geosphere is a good indicator of the geochemical conditions and processes. Hydrothermal synthesis experiments of rare earth fluorocarbonate minerals are carried out on starting materials with bastnaesite-calcite composition. Bastnaesite and calcite are main run products between 300C and 600C. At 300C and 350C, water vapor pressure, parisite may be slightly crystallized after 200 days run duration.

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The hydrate of high alumina cement with silica fume was observed by EPMA. Stratlingite was found in the hydrate on the investigation by XRD and EPMA

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We tried to synthesize homogeneous nano-polycrystalline cubic diamond by direct conversion of various forms of carbon.The experimental pressure was fixed at pressure 15 GPa, while the temperature ranged from 1500 to 2100 degrees Centigrade. The starting materials used were glassy carbon, fulleren, and a fine (~50 nm) powder of carbon. The recovered samples were analyzed by a micro-focus X-ray diffractmeter, Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and we found cubic diamond with granular grains of ~10 nm was formed at temperatures above 2000 degrees Centigrade when we used glassy carbon as a starting material.

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Monoclinic Bi6Sr8-xCa3+xO22 is known as a coexisting phase with the 2122-superconductor in the Bi-Sr-Ca-Cu-O system. This study clarifies the fundamental crystal-chemical features of the Bi6Sr8-xCa3+xO22 phase.

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Barrerite was first found with natrolite and heulandite from hydrothermally altered basalt in Funakoshi sea coast, Hirado Island, Nagasaki Prefecture, Japan. It belongs to stilbite group including stilbite, stellerite and barrerite. Crystallographic and optical examination reveals its orthorhombic symmetry, which is different from monoclinic one of stilbite. Alkali rich character of this mineral leads to compositional category of barrerite while stellerite has an abundance of divalent cation. Structural relationship among the zeolites of this group will be discussed here.

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Kamphaugite-(Y), bavenite, danalite and genthelvite occur in a druse-type pegmatite in a quarry at Hirono, Kameoka, Kyoto Prefecture, Japan. Electron microprobe analyses gave empirical formulae as follows; Ca1.82(Y1.65Gd0.13Dy0.12Er0.08Ho0.07Sm0.03Yb0.03Lu0.03Tb0.02Tm0.02)(CO3)4[(OH)2.05F0.13]?nH2O for kamphaugite-(Y), Ca4(Be3.15Al0.85)Si9.37O24.85(OH)3.15 for bavenite, Be3(Fe2.87Mn0.61Zn0.52) (SiO4)2.79S0.92 for danalite, and Be3(Zn2.19Fe1.08Mn0.73)(SiO4)2.86S0.98 for genthelvite.

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Fe oxides and hydroxides contained in a maghemite ore from the Kumano mine, Yamaguchi Prefecture, Japan were investigated in order to appraise previous studies reported by Shibuya (1958). The mineralogical characterizations were done using polarizing microscope, reflecting microscope, powder X-ray diffraction (XRD), and electron probe micro analyzer (EPMA). The ore mineral described as maghemite in his report is magnetite with clear compositional zoning of Si. Occurrence of hematite and goethite as alteration products of magnetite may indicate that even if metastable maghemite had formed by oxidation of magnetite, it already transformed to the stable hematite and/or goethite completely, or that magnetite altered to the stable mineral(s) directly.

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Anorthite megacrysts of about 1 cm in maximum diameter are found as phenocrysts in lavas of pyroxene-andesitic series on Kuchinoshima Island, Suwanosejima Island and Akusekijima Island, Tokara Islands, Japan. The anorthite megacrysts show little or no optical zoning, and are chemically homogeneous. Anorthite contents of the megacrysts are about 92 mol%. These textural features and crystal chemical data help us understand the genesis of the anorthite megacrysts from Tokara Islands.

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Deuterium enrichment of interstellar methanol is reproduced experimentally for the first time via grain-surface H-D substitution in solid methanol at 10 K. The mechanism proposed here represents a key route for D-enrichment that reproduces the high observed abundances of deuterated methanol (D/H ratio of up to 0.4, compared to the cosmic ratio of about 10-5), including multiple deuterations.

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Regolith breccias that were formed on the surface of asteroids often contain carbonaceous chondrite-like clasts. In this report, mineralogical features of the carbonaceous chondrite clasts in H chondrite regolith breccias are compared with those in howardites and those of micrometeorites. Most of the clasts in H chondrite regolith breccias contain only saponite or saponite and serpentine as phyllosilicates. Clasts that contain only serpentine as phyllosilicates are relatively minor. This tendency is similar to that of phyllosilicate-rich micrometeorites. However, among the carbonaceous chondrite clasts in howardites, CM chondrite-like clasts are the most abundant and CI chondrite-like clasts are less abundant than CM-like ones.

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Unequilibrated ordinary chondrites are classified into petrologic types 3.0-3.9. Grossman and Brearley [1] recently showed that Cr distributions in olivine are a highly effective tool for assigning petrologic types, and can be used to divide types 3.0 and 3.1 into 3.00 through 3.15. Kimura et al. [2] showed that the chemical compositions of spinel group minerals are related to petrologic type in LL chondrites. Kimura and Weisberg [3] suggested that the characteristic features of Fe-Ni metal are highly sensitive not only to thermal metamorphism, but also to host chondrule chemistry. Here we report the relationships between petrologic type and the characteristic features of Fe-Ni metal in type 3 ordinary chondrites.

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The existence of lonsdaleite in meteorites was checked by examining 120 carbon-rich grains from 10 ureilites by an x-ray diffraction method using a Gandolfi camera. Some carbon-rich grains accompanying compressed graphite with the smallest basal-spacing shows an x-ray powder diffraction pattern similar to that assigned to lonsdaleite by Hanneman et al.(1967). The results of this study reveal that the mineral showing a similar pattern to that of Hanneman et al. (1967) may be a disordered diamond and therefore lonsdaleite can not be found in meteorites in this study.

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Nakhlites are one group of igneous meteorites from Mars, and are classified into clinopyroxenites. 7 nakhlites have been identified in the world. Though nakhlites are petrographically different, the crystallization and cosmic exposure ages are common, 1.3 b.y. and ~10 Ma, respectively. Therefore nakhlites should have been derived from a single crater and fell at the different ages and in the various areas in the Earth. The purpose of the study is to examine the igneous body(ies) and the fomration history on the Martian surface based on the petrology.We have already presented the two different nakhlites of the Yamato nakhlites (Iame et al., 2005) and MIL 03346 (Imae and Ikeda, 2005), separately. Here we present these nakhlites based on the comparative petrology.

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Mare basalt volcanism is known to be initiated as old as 3.9 Ga, in roughly coincident with massive bombardment period. It is also believed that crypt-mare basalts erupted prior to the 3.9 Ga would probably be obliterated by massive bombardment around 3.9 Ga and subsequent basin-filling / veneer of mare basalt. Taylor et al. (1983) reported 4.23 Ga mare basalt cumulate clast from Apollo 14 breccia 14305 and suggested that mare-type volcanism commenced at least as early as 4.3 Ga in the Fra Mauro region. We studied a series of three thin sections including this ancient basalt. The modal abundances and mineral compositions of the basalt are successively evolved in the three within the cm scale. This indicates the presence of the small-scale (at least cm order) differentiation probably in a shallow intrusion or hypabyssal setting during the early lunar magmatism.

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LAP 02205 (LAP) is fifth crystalline mare basalt. We investigated its crystallization history using MELTS calculation and performing crystallization experiments. The results from both MELTS and crystallization experiments showed that the liquidus phase from the LAP bulk composition is olivine whose composition is more Fe-rich than the core composition of LAP olivine suggesting the xenocryst origin of the Mg-rich core of olivine. However, the core compositions and zoning sequences are similar among LAP and synthetic pyroxenes. Therefore, the LAP bulk composition is similar to its parent melt composition because olivine is rare in LAP (2~6%) The pyroxene and olivine mineralogy of experimental charges suggest 1-5 oC/hr cooling rate during the crystallization of the LAP magma.

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Yamato-86032 is a feldspathic lunar highland meteorite, mainly composed of several types of highland lithologies. The absence of KREEP components suggests that this meteorite is derived from the farside of the Moon. We found that one light-gray feldspathic lithology contains an augite-bearing clast that is different from known highland rocks from the nearside. Coupled with the mineralogical evidence from a magnesian feldspathic lunar meteorite Dhofar 489, we suggest that the lunar farside highland crust may have experienced more variable igneous processes than previously thought.

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Eighteen specimens have been reported as so-called "meteorite" in Mongolia(Mongolian People Republic). However only seven of them are recognized as true meteorites and they have been classified as 3 irons and 4 stones including one achondrite ureilite. Search for meteorites in Gobi Desert have been carried out by the Japan-Mongol joint team at 1974, 2002, 2003 and 2004. Unfortunately no meteorite found in Gobi Desert, however the joint team identified one meteorite, almost 2kg stone in some museum. The stone was display as one of terrestrial rocks in the museum of Saynshand City.

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