Abstract: 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:B203
molar ratio range from 1:1to 3:1 and up to O.25 in the B203 ratio
in the CaO-B203-H20 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.
*Department of Earth Sciences,Faculty of Education,Okayama University、**Division of Earth Sciences,Kurashiki University of Science and the Arts,Kurashiki、***Department of Earth Science,Faculty of Sciences,Okayama University、****Kurashiki Museum of Natural History
Abstract: 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 without 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.
Abstract: A Rietveld-refinement program, RIETAN-98, has two advanced features: partial profile relaxation and whole-pattem 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 frts between observed and calculated patterns, particularly in samples showing anisotropic profile broadening. Further, RJETAN-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-pattem fitting alternately. REMEDY is very useful for modifying incomplete structural models and analyzing highly disordered structures.
*National Institute for Research in Inorganic Materials、**Institute of Applied Physics, University of Tsukuba、***Advanced Science Research Center, Japan Atomic Energy Research Institute
Abstract: 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 I .7nm diamerter, and a surface of crystal can be closely observed under magnification of more than 100,000.
*Institute of Geoscience, University of Tsukuba、**Division of Research Facilitation,University of Tsukuba
Abstract: Electron-probe microanalysis
(EPMA) of the wavelength-dispersive (WD) type offers some advantage
in each quantitative 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
measurement positions, 25kV (accelerating voltage), LIF crystal,
the beam size of 20ｵm, emission current of lxl0-8A, 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.
*Chemical Analysis Center,University of Tsukuba、**Institute of Geoscience, University of Tsukuba、***Master's Program in Science and Enginerring, Graduate School,University of Tsukuba