Calcium-borate minerals such as takedaite and parasibirskite have been found in a vein in crystalline limestone near gehlenite-spurrite skarns at Fuka, Okayama Prefecture, Japan. The minerals are plotted in the CaO:B₂O₃ molar ratio range from 1 : 1 to 3 : 1 and up to 0.25 in the B₂O₃ ratio in the CaO-B₂O₃-H₂O system. This paper reviews the author's studies on physical and chemical properties and genesis of the borate minerals. The properties show the following characteristics with an increase of water content in the minerals: (1) the refractive indices, birefringence, hardness and density of the minerals decrease; (2) the endothermic peaks on the DTA curve shift remarkably at low temperature; (3) the intensity of IR absorption bands near 3400 cm^-1 increases, and the band near 1000 cm-1 shifts toward the lower frequency region. The formation of the minerals may be considered as follows: (1) takedaite was primarily formed by a reaction of boron-bearing fluids with limestone; (2) sibirskite and parasibirskite were formed by hydrothermal alteration of takedaite; (3) a late-hydrothermal solution converted sibirskite and parasibirskite to olshanskyite, frolovite and nifontovite.

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Zeolite-water heat pump system has been discussed as an example of innovative applied mineralogy. Zeolite and water is a marvelous combination to use low temperature waste heat including the solar heat for air conditioning with-out using any other energy such as electricity. A simple and small test model of the heat pump system using Mg, Na-A type zeolite bed has enabled to make ice repeatedly in a glass tube of the diameter of 3cm. Only hot water at 100°C was used as the heat source for dehydrating the zeolite. The lowest temperature of ice reached -18°C. The system will be promised for saving energy through various applications by using huge amount of low temperature heat sources which are wasted now in vain in the world.

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A Rietveld-refinement program, RIETAN-98, has two advanced features: partial profile relaxation and whole-pat-tern fitting based on a maximum-entropy method (MEM). Partial profile relaxation means that primary profile parameters of isolated reflections can be locally refined independently of secondary profile parameters. It was combined with three split-type profile functions to obtain better fits between observed and calculated patterns, particularly in samples showing anisotropic pro-file broadening. Further, RIETAN-98 has been combined with a MEED program for the MEM to grow into a joint software named REMEDY, which makes it possible to carry out MEM analysis and whole-pattern fitting alternately. REMEDY is very useful for modifying incomplete structural models and analyzing highly disordered structures.

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Ion-beam sputtering deposition is very useful to a nonconductive specimen-preparation technique for ultra-high to high resolution electron microscopy. Application of the sputtering has modified the ion-beam thinning apparatus for preparation of the sample for TEM. Effective use of our modified sputtering apparatus leads to a good conductivity of the Pt-coating composed of finer particles in 1.7nm diamerter, and a surface of crystal can be closely observed under magnifi-cation of more than 100, 000.

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Electron-probe microanalysis (EPMA) of the wavelength-dispersive (WD) type offers some advantage in each quan-titative analysis of various kind of rare-earth elements in minerals with their high concentrations. Close observation on WD spectra of REE in minerals leads to a skillful selection including the favorable conditions: a suitable choice of background mea-surement positions, 25kV (accelerating voltage), LW crystal, the beam size of 20μm, emission current of 1×10^-8A, and the ZAF corrections. This accelerating voltage is indispensable in quantitatively analyzing various kinds of REE in minerals. As tested on thortveitite, the present EPMA has proved to be correct for REE-pyrosilicates.

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