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We have investigated the thermal expansion of 15 naturally occurring chemically diverse amphiboles utilizing high-temperature X-ray powder diffraction. As done in the first paper of this series on pyroxenes, volume-temperature data were analyzed using the physical Kroll and empirical Fei thermal expansion models. As in pyroxenes, orthorhombic amphibole end-members expand more than monoclinic ones, which is related to the greater kinking of the chains of tetrahedra permitted by the Pnma symmetry. In the case of chemically similar phases, increased Al in octahedral cation sites decreases expansion. Although the ranges of thermal expansion coefficients for amphiboles and pyroxenes are similar, expansion patterns are not the same. Amphiboles exhibit higher expansion along a*, but lower along b, just the reverse of that observed in pyroxenes. An exception to this is the data for pargasite, which shows higher expansion along the b axis due to the presence of Al in tetrahedral sites. Current data will be useful in modeling reactions involving amphiboles in both metamorphic and igneous environments.

Thermal modeling of Raman spectra of forsterite in the framework of Phobos environment supporting the synergetic work between RAX and MiniRAD in JAXA MMX mission.

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Albite is one of the most common minerals in the Earth's crust, and its polymorphs can be found in rocks with different cooling histories. The characteristic spectrum of vibration of the albite mineral reflects its structural Si/Al ordering. In this study, we report on the comparison between the Raman spectra measured on a natural and fully ordered (as deduced on the basis of single-crystal X-ray diffraction data) 'low albite', NaAlSi3O8, and those calculated at the hybrid Hartree-Fock/density functional theory level by employing the WC1LYP Hamiltonian, which has proven to give excellent agreement between calculated and experimentally measured vibrational wavenumbers in silicate minerals. All the 39 expected Ag modes are identified in the Raman spectra, and their wavenumbers and intensities, in different scattering configurations, correspond well to the calculated ones. The average absolute discrepancy |Δv¯| is ∼3.4 cm-1, being the maximum discrepancy |Δv|max ∼ 10.3 cm-1. The very good quality of the WC1LYP results allows for reliable assignments of the Raman features to specific patterns of atomic vibrational motion.

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Natural feldspars are framework silicates and among the most common rock-forming minerals of planetary crusts. Our aim is to determine the Raman spectral characteristics of feldspar-group minerals, in order to build a consistent set of Raman spectra and to recognize them in all possible specimens of natural sediments and man-made pottery and tools of archaeological value. Sediments represent in fact the principal inorganic raw material employed in ancient times to produce ceramics. The characterization of Na- versus K-rich alkali feldspars in pottery fragments is complex due to heterogeneity of materials used and presence of both crystalline and amorphous phases1,2. Raman spectroscopy is an innovative, efficient, and user-friendly technique representing the ideal complementary tool to classical provenance analysis of sediments and sedimentary rocks. The method is non-destructive, does not require specific preparation, and can be used also directly on thin sections and polished rock. Detrital feldspars are determined by comparison of Raman peaks observed on our samples with reference spectra reported in the literature calibrated spectra obtained from minerals of specific chemistry and mineralogical databases available online. It is often convenient to photograph and label each single grain on the thin section or grain mount, in order to observe optical properties under the microscope before and after identification with Raman spectroscopy. Raman spectroscopy is a powerful tool to confidently identify dubious grains independently of their size and orientation. Last but not least, it allows routine identification of minerals as fine grained as fine silt6, and it is consequently an unrivalled tool for quantitative analysis of silt and siltstone, which represent a huge fraction of fluvial, turbiditic and eolian transport. A comprehensive study of vibrational mode behaviour in a wide variety of natural feldspar-group minerals is useful for geologist, archeologist and industry.

A 7-year-old dog was presented with a history of an open lesion on the right thoracic wall, discharging honey-like fluid and small stones. Ultrasonography and computed tomographic fistulography identified a cholecystocutaneous fistula; cholecystectomy was curative. Veterinarians should consider this disease in patients with long-term discharging lesions on the right thoracic or abdominal wall.

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