The Yokozuru, Suisho, Tokoya, Sotan, Zurine and Usagida deposits are distributed around Mt. San-notake. They are contact metasomatic hydrothermal ore deposits formed in the contact between the Paleozoic limestone and the Kawara granodiorite that intruded in the Cretaceous period. Skarn zones are divided into two main zones, clinopyroxene zone and garnet zone. Based on the mineral assemblages the former is subdivided into three zones, A-, B- and C-zones, and the latter into two zones, D- and E-zones. A-zone is composed of plagioclase, alkali feldspar, quartz, hornblende, clinopyroxene, actinolite and opaque minerals, B-zone of quartz, clinopyroxene, garnet and opaque minerals, and C-zone of clinopyroxene, garnet, calcite and opaque minerals. D-zone includes garnet, clinopyroxene, chlorite, epidote and opaque minerals, and E-zone garnet, calcite, epidote, actinolite, quartz and opaque minerals. Sulfide mineralization occurred in the C-, D- and E-zones, and limestone zone. The main ore minerals are chalcopyrite, pyrite, pyrrhotite and sphalerite. Many kinds of Bi-, Te- and Ag-minerals were also found in a small quantity. They are bismuthinite, native bismuth, tetradymite, hessite, wittichenite, gustavite, aleksite, cuprobismutite, cosalite, argentite and so on. The FeS content of sphalerite coexisting with pyrite and chalcopyrite ranges from 13.6 to 19.8 mol.%, and the composition of pyrrhotite coexisting with pyrite varies from 46.9 to 47.4 Fe at.%. Based on the main mineral assemblages and the chemical compositions of sphalerite and pyrrhotite, it is suggested that the temperature-sulfur fugacity condition of the mineralization in the San-notake district locates in the pyrite-stability field near pyrite-pyrrhotite univariant curve in high temperature (400°-500°C) and cuts the univariant curve between 350° and 300°C. At later stage many Bi-Te-Ag-Pb-Cu-Fe Ni-Co-S minerals were produced, and the temperature-sulfur fugacity condition is estimated to be around the bismuthinite-bismuth univariant curve.

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Crystal structures have been refined from single-crystal X-ray diffraction data for eight synthetic (Li, Na)GaSi₂O₆ clinopyroxenes, crystallized at 1770 K/6 GPa or annealed at 573 k/l atm. The space group is C2/c and Z is 4. The structures of the lithium rich pyroxenes are similar to that of spodumene(LiA1Si₂O₆) and the structures of the sodium rich pyroxenes are similar to that of jadeite(NaA1Si₂O₆). Although the crystallographical Ga site is only one in the (Li, Na)GaSi₂O₆ pyroxene, the correlations between the mean <Ml-O1> distance and the M1-O2 distance and between the O1-Si-O2 angles and the differences, d_br-nbr (=mean <Si-O(br)>-mean <Si-O(nbr)>), where br denotes bridging and nbr nonbridging, suggest that there are two different electronic states for the octahedral Ga ions.

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Manganese deposits of the Noda-Tamagawa mine are metamorphosed equivalents of bedded type. The ores are typically zoned with a central pyrochroite-hausmannite, outer tephroite, and the outermost rhodonite ores are closest to the wall rock chert. The δ¹⁸O(SMOW) values of 11 tephroite, 15 rhodonite and 5 quartz samples in the manganese ores and chert were determined to be in the ranges of 9.9-16.4‰, 11.3-19.6‰, and 22.3-23.8‰, respectively. The overall order of ¹⁸O enrichment corresponds to the order of equilibrium fractionation among these minerals. However, the isotope temperatures calculated from quartz-rhodonite and rhodonite-tephroite pairs from neighboring ore zones did not give temperatures consistent with those estimated from the mineral assemblage in the wall rocks. This discrepancy suggests that the amount of oxygen-bearing fluid, either H₂O or CO₂, was small during the metamorphism.
     The δ¹⁸O values for MnCO₃, the most probable candidate of the primary manganese mineral, were calculated from the oxygen isotope mass balance among manganese silicates, silica mineral, and CO₂ to be 17.0-20.0‰. If the MnCO₃ initially precipitated from fluids of δ¹⁸O=0.0-2.5‰, the temperatures of precipitation can be calculated to be between 75° and 127°C. These temperatures suggest that the primary MnCO₃ was precipitated by submarine hydrothermal solutions.

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Fluor edenfite was found in cavities of the Ishigamiyama lava dome building two pyroxene-hornblende-andesite in the Kimpo volcano, Kumamoto, southwest Japan. The fluor edenfite is associated with tridymites and magnetites in the cavities. This is the first description of volcanic fluor-amphibole, and its chemical analysis was made by combining microprobe, vacuum-heating method and Mössbauer spectroscopy. The Ishigamiyama fluor edenite has 1.47F, 0.13OH, 0.03Cl and 0.37O pfu in the O3 site, and thus, is characteristically poor in (OH). This edenite is the most F-rich one in edenites and edenitic hornblendes previously reported.

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