Mineral surface-textures on naturally weathered c of staurolite [monoclinic, pseudo-orthorhombic; Fe4Al18Sis046( rtalS indicate that staurolite weathering is general1 interface-limited. Etch pits on naturally weathered staurolites are disi-shaped, extensive parallel to (OIO), and thin perpendicular to (010). (010) is the plane of weak bonding and weak cleavage and the orientation of common stac...

A common perception among petrologists is that Al is immobile in most geologic processes, and, therefore, the conversion of gabbro with high Al-content (16-18 wt. % Al2O3) to granitic rocks with lesser Al-content (12-13 wt. % Al2O3) by Kand Si-metasomatism is not possible. The mobility of Ca, Mg, and Fe is not doubted in hydrothermal fluids, but Al is thought not to be mobile. Two different ter...

Using IR absorption data from polarized measurements on single-crystal minerals with stoichiometric water contents (in the form of H2O or OH groups in the structure), a linear calibration curve (r2 ø 0.98) for water in minerals is established in the form: ei (the integrated molar absorption coefficient in units of cm22 per mol H2O/L) 5 246.6(3753 2 n) (n 5 the mean wavenumber of the OH stretchi...

for the first time, an unusual assemblage of talc-phengite-chlorite-k-feldspar was found in quartz schists from the sanandaj-sirjan zone in the nahavand area in western iran. the talc-bearing quartz schists occur as small bodies or lenses within pelitic schist layers and contain talc, phengite, chlorite, k-feldspar and quartz as major mineral constituents with subordinate amounts of calcite ...

Chloritoid and kyanite coexist in metapelites from the high-pressure/low-temperature Massa Unit Alpi Apuane metamorphic complex (Northern Apennines, Italy). The composition of chloritoid is extremely variable throughout Unit. Fe-chloritoid occurs association with hematite-free, graphite-bearing schists, whereas strongly zoned Fe-Mg found hematite kyanite. We investigated effect different bulk F...

A new two-dimensional magic-angle spinning NMR experiment1,2 using multiple-quantum coherences of half-integer quadrupolar nuclei was used to study 27Al sites in crystalline samples of leucite (KAlSi2O6), anorthite (CaAl2Si2O8), and kyanite (Al2SiO5), as well as CaAl2Si2O8 glass and a magnesium aluminoborate glass. In the crystals, multiple sites are partially resolved and new results for isotr...