Solubilities of Al₂O₃ in PbO-B₂O₃ flux were investigated in various mole fractions of B₂O₃ at 1, 300°C, 975°C and 600°C, and growth condi tion of corundum crystal in the flux were studied. Heat of solution and related thermodynamic values were calculated corresponding to the B₂O₃mole fractions. Two regions may be distinguished concerning with the changes of these thermodynamic values versus B₂O₃ mole fractions ; one region is more than 0.2 mole fraction of B₂O₃ and the other is less than 0.2 mole fraction. It is concluded that the solubility is significantly affected by the chemical interaction between solute and solvent. Moreover, a Co-doped corundum was synthesized by the same flux growth technique, where the crystal formed a pale green-colored transparent and thin plate containing 0.06 wt.% of Co (III) . Lattice para meters of the Co-doped corundum are as follows.a=4.757±0.001Åc=12.989±0.010Å Since these values are almost the same as those of the corundum with out any dopants, Co atom seems to substitutionally occupy the Al site in its crystal structure.

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Buddingtonite was found near the Toshichi spa, Hachimantai geother mal area, Iwate Prefecture. It replaces plagioclase crystals in the hydrothermally altered pyroclastic rocks of the Quternary Hachimantai vol canic group. Buddingtonite is associated with montmorillonite, pyrite and gypsum. The unit cell parameters are a=8.568(3), b=13.048(2), c=7.197(2) Å, .A=112.83(3).K, v=741.5(3)Å. The ammonia content of whole-rock specimen determined by the Kjeldahl method is 0. 527 weight percent and elemental analysis at elevated temperatures shows loss of ammonia from the specimen above 500°C. Ammonia content in the surrounding active hot-spring waters is very low, but buddingtonite in this study was probably formed by the Quaternary geothermal activities.

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An anomaly near at 243°K in Bi₄Ti₃O₁₂ was found by dielectric and X-ray diffraction studies. The details of this anomaly is not well known at present, but it is concluded that at this temperature the framework of the crystal structure remains unchanged from that at room temperature, whereas the electron cloud distribution in the crystal may somewhat change.

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Naturally occurring seventeen manganese dioxide minerals, cryptomelane (ishiganeite), hollandite, manjiroite, cororadite, pyrolusite, nsutite (yokosukaite), ramsdellite, birnessite, ranciéite, takanelite, todorokite, lithiophorite, psilomelane, chalcophanite, hydrohetaerolite, auroite and amorphous manganese dioxide mineral, from Japan were briefly reviewed from the stantpoints of descriptive mineralogy, together with the relation between the terrestrial manganese dioxide minerals and the composition of manganese nodules.

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