Poughite, frohbergite, and melonite are found in ore samples from the Kobetsuzawa Mine in Hokkaido. Poughite is associated with secondary minerals, tellurite, anglesite, cerargyrite, and limonite. Occurrence of the mineral appears to have derived from the alteration of pyrite, altaite, and hessite. Frohbergite and melonite are associated with altaite, hessite, petzite, tellurantimony, native tellurium, sylvanite, rutile, chalcopyrite, stibnite, pyrite, and arsenopyrite. Such complicated association of the tellurium-bearing minerals with rutile is rare in nature.

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The best examples of bacteriogenic mineralization in the geologic record came from the Precambrian Gunflint Iron Formation in Canada. About 250 minerals are now considered to be biomineralization product and the biomass may control their environmental behavior. The bacteria present in almost all places, such as soils, lakes, acid mine drainage, cement concrete, sludge and deep-sea sediments at temperatures from freezing to hundreds degree cen-tigrades and wide range of pH. Recent examples of bacteriogenic mineralization drawn from areas impacted by industrial activity give the evidences that bacteria can support high rate of mineral precipitation. TEM photographs show that bacterial cell wall is essentially occupied by crystalline materials. Interaction between in-organic physical processes and the biological processes occurs at the interfacial of bacteria and solution. Extensive microbial activity in response to environmental change are the most sensitive factors modyfying the surface of our planet.

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Interplanetary dust particles (IDPs), collected in the Earth's stratosphere, have been a subject of intense laboratory studies for the last ten years. A significant proportion of collected IDPs has a composition close to the solar (or chondritic) elemental abundance. This paper reviews results of mineralogical, petrological and chemical studies of the chondritic IDPs. Experimental studies on mineralogy, infrared absorption spectra, and isotopic properties of the chondritic IDPs have suggested that they are primitive and may contain records of the early solar system and possibly of events that predate it. Specific mineralogical and chemical features provide indications of processes including direct condensation from the solar nebula, hydrocarbon formation in the nebula, and aqueous alteration in water-rich parent bodies. Of particular interest are the mineralogical and chemical relationships between IDPs and carbonaceous chondrites. Data of both IDPs and carbonaceous chondrites have accumulated, and it is now possible to compare the mineralogies of the IDPs and the meteorites in considerable detail. Important points of information and their implications for the origin of IDPs are discussed. The current knowledge of mineralogy and chemistry of IDPs suggests that most hydrated IDPs were derived from asteroids and most anhydrous IDPs were derived from comets.

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Only 2400 meteorites were known in worldwide before the find of the Antarctic meteorites. However, during the last 20 years, 12000 meteorites have been collected from Antarctica by the efforts mainly of the Japanese and US expeditions. Over 8500 of them are Japanese collection, which is the largest one in the world. Antarctic meteorites included not only all known types but new types and numerous unique specimens. The meteorites are among the most primitive materials in the early solar system. Those meteorites have been studied by numerous scientists of a variety of background including petrology, mineralogy, geochemistry, organic chemistry, geophysics, isotopic-chronology and geomagnetism. They provided many excellent results including identifications of new types, detail petrology on primitive meteorites, reconstruction of HED meteorite parent body, origin of ureilites and detail isotopic data of various meteorites. However much more work remains to be done before we can fully understand the origin and evolution of the solar system including the earth as one of the planets.

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GEMS-IIT, a handy version of computer-aided registration-retrieval system for mineral specimens, has been released as a subsystem of GEMS-II, an electro-data processing system for geological specimens and installed into the central computer system of Tsukuba Science Center, MITI. Database management system of GEMS-IIT is prin-cipally supported by dBASEIIIPLUS because of its refined operation utilities and reasonable cost performance. The subsystem, consequently, is easy to adopt for desktop personal terminals either with on-line or off-line mode. Throughout the process of system analysis, special attention has been paid on the unique data characteristics of geological specimens, such as “fuzzy” definitions for keywords, heterogeneous data structure, selection of attributes for search, relation to the storage method, and so on.

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A new system has been constructed for high temperature transmission electron microscopy (HTTEM) to investigate phase transformation of silicate minerals. This HTTEM system, available up to 1200-1300°C, was successfully applied to high_??_low phase transitions of Ca-poor clinopyroxenes. This phase transition was in-situ observed for the first time under HTTEM and was revealed to be a thermoelastic type of martensitic transformation. Formation process of antiphase boundaries in pigeonite was also in-situ observed during the phase transition under HTTEM.

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Successful applications of SR-XRF technique to the analyses of earth and planetary minerals were demonstrated. The measuremnts were made at Photon Factory, Tsukuba utilizing an XRF system with Si(Li) detector and monochormatic X-ray obtained with Si (111) double crystals. Advantages of SR-XRF technique over conven-tional techniques were illustrated through the following examples of applications. Microprobe Fe and Ti K-XANES spectra of chondrule in meteorites were measured by X-ray fluorescent detection and their oxidation states were clarified. Two dimensional chemical state analysis of a geological sample was made based on the selective excitation of specific chemical species by using tunable SR and revealed two dimensional distribution of Fe⁰, Fe²⁺, and Fe³⁺ in the sample.

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MINES estimates mineral names from given chemical compositions by comparing with registered chemical analysis data of minerals. The data file recorded in a 1 Megabyte floppy disk is modifiable. Estimations were mostly successful when the registered data exceeded 3000 records. The time needed for estimation is mostly within a few minutes. MINES canbe applied globally to all mineral analysis data, as well as microprobe data.

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