The structure of shock-induced anorthite-glass obtained by shock-recovery experiment, which is called “diaplectic glass”, has been investigated with X-ray diffraction method and compared with that of fused anorthite-glass. The peak profiles on the diffraction curve of the glass are broader than those of the fused glass. The radial distribution function indicates that the basic structural units are TO₄ (T = Si, Al) tetrahedra also in the diaplectic glass, having similar linkages to those in the fused glass. The peaks of the radial distribution curves are broader in the diaplectic glass than in the fused glass. Therefore, the range of ordered arrangement of atoms of diaplectic glass seems to be smaller than fused anorthite-glass. The broadness is more distinct in the peaks related to Ca.

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The crystal structure of katayamalite has been determined by Patterson method and refined by the least-squares method using single crystal diffractometer data, giving R = 0.057 for 5785 reflections. Formula: (K,Na)Li₃Ca₇(Ti,Fe³⁺,Mn)₂[Si₆O₁₈]₂(OH,F)₂. Cell dimensions: a 9.721(2), b 16.923(3), c 19.942(3)Å, α 91.43(10)°, β 104.15(11)°, γ 89.94(10)°, space group C-1, Z = 4; or a 9.763(2), b 9.721(2), c 19.942(3)Å, α 104.15(11)°, β 81.76(9)°, γ 119.92(10)°, space group P-1, Z = 2. Katayamalite is a ring silicate with two-layered structure parallel to (001), and consists of Si₆O₁₈ rings connected with Ca–(O,OH) octahedral sheets, and with Ti–O octahedra, Li–O tetrahedra, and 12-fold K polyhedra. The crystal structure of katayamalite is very similar to that of baratovite. However, the distortion in the katayamalite structure results in the lower symmetry of triclinic system. Half of the motifs of the katayamalite structure and the baratovite structure are similar to that of cordierite, and we can propose the following structure series; beryl → cordierite → katayamalite and baratovite.

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Cookeite was found in stibnite-pyrite-quartz veins of the Caracota mine, Bolivia. It is commonly ivory white in color with a pearly luster. The wet chemical analysis (containing 2.70 wt% Li₂O) gives the formula of Li_0.975(Al_3.921Na_0.060Ca_0.039Mg_0.017Fe_0.006³⁺)_4.043 (Si_3.064Al_0.936)_4.00O₁₀(OH)₈. The X-ray powder diffraction gives a pattern of Ia cookeite and the cell dimensions of a = 5.163(2), b = 8.957(2), c = 14.235(2)Å and β = 97.07(3)°. The results examined from optical properties, specific gravity, and an infrared spectrum warrant the substantial cookeite.

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