Divalent ions of the first series transition elements and Hg were introduced into a cadmium hydroxyapatite Cd₅(PO₄)₃OH by replacing a part of Cd²⁺, and the effects on the crystal growths and the structural changes were studied. Cd²⁺ can be exchanged with Mn²⁺ up to about 30 mol %, with Ni²⁺ or Hg²⁺ up to about 10 mol %, and with a little amount of Fe²⁺ or Cu²⁺. It was found that Cd₅(PO₄)₃OH forms a superstructure when it contains a small amount of Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺ or Hg²⁺ ion. Infrared spectra of Cd₅(PO₄)₃OH containing these ions show some new bands in addition to those of Cd₅(PO₄)₃OH. The average structures of the crystals containing a small amount of Hg²⁺ and Ni²⁺, and the superstructure of the crystal containing Mn²⁺ were refined with the full-matrix least-squares method, although the amounts and sites of the substituting ions could not be determined except for the crystals containing Hg²⁺. The superstructure belongs to P6₃ (a=16.1990(3), c=6.6485(1)Å and Z=6) and has more distorted PO₄ tetrahedra than the structure of pure Cd₅(PO₄)₃OH.

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The infrared absorption spectra of the grossular–hydrogrossular series have been recorded for hydrothermally synthesized materials. The compositions of the prepared materials are Ca₃Al₂(SiO₄)_3−x(O₄H₄)_x (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0). Infrared absorption patterns of these garnets were given by the KBr method in the range of wave number from 4000 cm⁻¹ to 250 cm⁻¹ after drying in a vacuum desiccator with Mg(ClO₄)₂. The results showed a close relation between the spectrum patterns and the amounts of constitutional water in these garnets. The linear relation between the chemical composition and the ratio of logarithmic transmittancy, was observed for 14 pairs of absorption bands and/or transmission ones. This implies the possible use of the infrared absorption method in the determination of the amount of water in garnets of this series.

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A ceramic waste form of a SYNROC type (Ringwood et al., 1979) was synthesized by heating after hot-pressing to examine its constituent phases and distribution of simulated high level waste elements by means of X-ray diffractometry and analytical electron microscopy, respectively. Only three phases, hollandite, BaAl₂Ti₆O₁₆, perovskite, CaTiO₃ and zirconolite, CaZrTi₂O₇ occurred along with unidentified phase(s) which had a few very low peaks in the X-ray diffractogram. Distribution of elements among the three constituent minerals was examined and the results revealed the following notable features: Mo was found in perovskite instead of forming water-soluble Cs-molybdates, and larger amounts of rare earth elements were accommodated in perovskite than in zirconolite. The results of the distribution of elements were compared with the results by other investigators who adopted different fabrication processes.

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