Gonnardite, phillipsite and gismondine occur as euhedral to subhedral crystals in the cavities of calcareous xeno-lith. Thomsonite and a scolecite-like zeolite often replace nepheline crystals, and rarely fill up minute vesicles in nephelin-ite. The chemical analyses were made by EDS. The most Na-rich gonnardite is (Na_6.61Ca_1.36)Σ_7.79 [Al_9.11Si_10.84O₄₀] nH₂O, and the most Na-poor one is (Na_5.21Ca_1.72)Σ_6.93 [A1_9.47Si_10.47O₄₀]· nH₂O. Phillipsite-K and phillipsite-Ca are rec-ognized. The former is (K_2.11Ca_1.71Na_0.93Ba_0.10)Σ_4.85[Al_6.73Si_9.29O₃₂] nH₂O in association with Na-rich gonnardite, and the latter is (Ca_1.92K_1.32Na_0.79Ba_0.53)Σ_4.56[Al_7.13Si_8.90O₃₂]·nH₂O in association with Na-poor gonnardite. Gismondine has a narrow compositional variation with minimum Ca/(Na+K+Ca)= 0.92 and Al/Si = 0.95-0.97 in tetrahedral framework, and Na- and K-bearing one is (Ca_0.96Na_0.04K_0.04)Σ_1.04[Al_1.96Si_2.03O₈] ·nH₂O. Thomsonite also has a narrow composition-al variation with Ca/(Na+K+Ca) = 0.62-0.69 and Al/Si = 0.95-0.99. One of thomsonite existing in boundary of nepheline and gonnardite is (Ca_2.03Na_1.14)Σ_3.177[Al_4.91Si_5.01O₂₀]· nH₂O. Due to very minute grain of a fibrous zeolite, exact identi-fication of species by X-ray powder diffraction was not made. As the chemical composition is close to known scolecite, it is tentatively called as scolecite. It is small compositional variation except minor substitution for Ca by Na in case of re-placing nepheline. The composition of vesicle filling one is, (Ca_0.99Na_0.05)Σ_1.04[A1_2.02Si_2.98O₁₀]· nH₂O. These zeolites found in cavities have been formed under the reaction with nephelinite magma and calcareous xenolith.

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It is one of important subjects in earth and planetary sciences to analyze the textures of rocks quantitatively. For the purpose some digital imaging techniques, including back-scattered electron imaging and characteristic X-ray imaging with a scanning electron microscope (SEM) or a electron probe micro-analyzer (EPMA), and optical imaging with a CCD digital camera or a image-scanner etc., have been applied. We applied here a scanning X-ray analytical microscope (SXAM) for the first time in the field of earth and planetary sciences to obtain XRF images of rocks. In this paper, we report the new method of image processing in which the X-ray maps of a rock are transformed to the maps that show distribution of mineral composition. As a test case, the X-ray maps of the Ryoke granite from Teshima, SW Japan, were processed to make the distribution maps of major minerals. XRF intensities of major elements were assumed to have linear relationship with the composition of major rock-forming minerals in each pixel. The coefficients between XRF intensities and mineral compositions were determined by picking up the some pixels at which a pure mineral exists. The composition of minerals was then calculated by maximum likelihood (ML) method for Gaussian distribution i.e. least-square method. It was shown that it was plausible by a numerical experiment to adopt the least-square method when the operation time of SXAM is sufficiently long. We found the sources of errors of the processed mineral maps depending on statistical errors of X-ray counts, variation of chemical composition in each mineral, and a condition of a sample's surface etc., and propose the way of estimating the errors. As an application, the mineral maps was applied to modal analysis of minerals.

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This review describes the method of Britt and Luecke (1973), which is applicable to the calculations of parame-ters relevant to the mixing properties of solid solutions. Based on the experimental results on ion-exchange reactions of (Fe, Mn, Mg)TiO₃-(Fe, Mn, Mg)Cl₂(aq) at 600°C and 98MPa (Kubo et al., 1992), this paper computes the Wilson parame-ters for the (Fe, Mn, Mg)TiO₃ solid solution and the Gibbs energy changes of the individual binary exchange reactions.

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A practical application of the ALCHEMI technique as applied to minerals, including its historical background and underlying principles, is given. As it is sometimes unclear whether or not strong localization of the Bloch wave field occurs at proper sites even in a simple mineral solid-solution, dynamical calculation for the end-member chemical compositions, often needs to be carried out to show on which reflection planes Bloch waves would localize. In the diopside-structure under the g=020 planar channeling condition, Bloch waves localize on M(1)+T and M(2) for s₀₂₀<O and s₀₂₀>O respectively, regardless of whether the M(1) site is occupied by a lighter element(such as Mg) or a heavier element(such as Co) than the Ca in the M(2) site. However, systematic row reflections OkO which must always be excited to some extent in practice as well as projected cation arrangements staggering along (020) planes will weaken the localization effect in this type of experiment. As an example of an axial-channeling case, the [111] zone-axis incidence for garnet(Mg₃Al₂Si₃O₁₂ and Fe₃Al₂Si₃O₁₂) has also been described. In experimental details, the g=020 channeling case for polycrystalline diopside powder was compared with the result of a single-crystal X-ray study. Although the electron-optical set up of the TEM for an ALCHEMI experiment is almost the same as that for normal electron diffraction, it requires some skills to attain a proper orientation of a crystal fragment of a powder specimen, particularly one whose structure has low symmetry. The general course of action to be taken is explained using the case of diopside(C2/c) as an example.

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IMA(国際鉱物学連合)の新鉱物・鉱物名委員会で承認された新鉱物を下記に紹介する.　記載が発表されているものについては,鉱物名と著者も掲載しているが,まだ未記載のもについては,化学組成,結晶系,空間群,格子定数,色,光沢,透明度,光学的性質,X線粉末回折値の主な回折線のみを示す.

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