The studies of each pit formation of fission fragment tracks in natural quartz are carried out using KOH, as the track etchant. The influence of crystallographic structure on the bulk etch rate, V_G, the track etch rate V_T, and the etching efficiency, η is reported. The value of fission track age is found to be the same for all the planes. It is observed that the annealing augments anisotropy of track revelation in the crystal. The activation energy, E_a, is found to vary with the crystallographic orientation.

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Semi-empirical molecular orbital study (CNDO/2) has been performed for a large cluster of atoms (Mg(1)₃Mg(2)₂Si₂O₂₂H₂₆)⁰⁺ to evaluate cation charges of forsterite. Hydrogen (H) atoms were attached to outer oxygens of the cluster to keep local neutrality. The cluster included all the polyhedra which share edges with the Mg(1)O₆ and Mg(2)O₆ octahedra and the SiO₄ tetrahedron under consideration for cation charges. The convergence in the energy minimization was successfully achieved for this cluster. The obtained cation charges were 0.62–0.63, 0.80–0.81 and 1.24–1.34e for Mg(1), Mg(2) and Si atoms, respectively. The charge of Mg(2) showed a larger value than that of Mg(1), which indicated that M(2) site of olivine was more ionic than M(1) site. This result is consistent with the previous works of experimental charge determination by X-ray method and calculation of electrostatic site potentials. The Si atom showed a higher valence value comparing with Mg atoms.

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High-resolution electron microscopy was performed on a new manganese dioxide (Rb_0.27MnO₂) with a giant tunnel to clarify the problem whether the 2x5 tunnel exists as a uniform structure unit, or some lattice defects or intergrowths must be present to stabilize such a giant tunnel. Neither defects nor intergrowths were observed in the crystal, and all the lattice images showed uniform fringes, indicating that the compound exists as a homogeneous crystal.

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