Results 221 to 230 of about 4,580 (237)

Pressure-induced (Al,Si)[4]-ordering in dioctahedral micas?

Contributions to Mineralogy and Petrology, 1984
Pure, synthetic 2M1-muscovites (Ms) and 2M1-paragonites (Pg) prepared at 7, 13.5, and 18 kbar \(P_{{\text{H}}_{\text{2}} {\text{O}}} \) have been subjected to careful X-ray powder diffractometry and IR powder spectrometry. The results of X-ray studies show that the lattice constants of these micas are independent of the pressure employed in ...
Langer, K., Chatterjee, N. D., Flux, S.
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ChemInform Abstract: Protonation—Deprotonation of Dioctahedral Smectites.

ChemInform, 2002
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
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Nature of dioctahedral micas in Spanish red soils

Clay Minerals, 1997
AbstractStructural formulae and other crystallochemical parameters were used to study different species of dioctahedral micas in clay and coarse gravel fractions of horizons from a red soil (Ultic Haploxeralf) in southern Spain. Mineralogical analyses using X-ray powder diffraction, and measurements of theb0parameter revealed dioctahedral micas, illite
J. M. Martin-Garcia, G. Delgado, M. Sanchez-Maranon, J. F. Parraga, R. Delgado   +4 more
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Tetrahedral charge and Fe content in dioctahedral smectites

Clay Minerals, 2017
AbstractNatural aluminosilicates can contain Fe in tetrahedral or octahedral coordination. Amongst smectites, tetrahedral iron is known to occur in Fe-rich nontronites but few indications exist for the presence of tetrahedral Fe in smectites of the montmorillonite–beidellite series.
Kaufhold, S., Stucki, J. W., Finck, N., Steininger, R., Zimina, A., Dohrmann, R., Ufer, K., Pentrák, M., Pentráková, L.   +8 more
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Interstratification of trioctahedral and dioctahedral smectites through delamination and costacking

Journal of Colloid and Interface Science, 2008
Trioctahedral and dioctahedral organosmectites delaminate in 1-octanol to give stable monolayer colloidal dispersions. Addition of acetone to a mixture of these colloidal dispersions yields a composite of the two clays. Layers of the two smectites are interstratified in the composite.
Venugopal, BR, Ravishankar, N, Rajamathi, Michael   +2 more
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Structural Factors Controlling Stacking Sequences in Dioctahedral Micas

Clays and Clay Minerals, 1971
AbstractDeviations in the symmetry of mica single layers from the ideal arrangement with all atoms in hexagonal arrays are caused by the structural factors such as compositional variation (substitutions), order-disorder, and distortions. The derivative crystal structure theory as applied to mica polymorphism, implies that the ideal symmetry of the mica
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Synthesis and characterisation of dioctahedral smectites.

2004
The synthetic clays are used in a lot of studies to analyse clay properties. They permit to have samples without impurities and with a specific chemical composition. In synthetic smectite group, trioctahedral smectites as saponite were generally studied.
Lantenois, Sébastien, Muller, Fabrice, Champallier, Rémi, Bény, Jean-Michel   +3 more
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Crystal-chemical microheterogeneity of Precambrian globular dioctahedral mica minerals

Lithology and Mineral Resources, 2013
The paper presents a novel method for determining the crystal-chemical heterogeneity of finely dispersed dioctahedral 2: 1 mica mineral phases based on the modeling of their powder diffraction patterns. We used three samples, which were taken from Lower-Middle Riphean rock sections of the Anabar and Olenek uplifts in northern Siberia, and one sample ...
V. A. Drits, B. A. Sakharov, T. A. Ivanovskaya, E. V. Pokrovskaya   +3 more
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Catalytic Properties of a Heated Ammonium-Saturated Dioctahedral Smectite

Collection of Czechoslovak Chemical Communications, 2000
A series of acid catalysts was prepared by heating of NH4-saturated montmorillonite at 200-600 °C for 24 h. Their catalytic activity was tested in acetylation of 3,4,5-trimethoxybenzaldehyde with acetic anhydride. This reaction is sufficiently sensitive to modification of the catalyst and thus suitable for testing catalytic activity of modified ...
Ľuboš Jankovič, Peter Komadel
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Infrared Evidence of Dioctahedral-Trioctahedral Site Occupancy in Palygorskite

Clays and Clay Minerals, 2002
AbstractA Mg-rich palygorskite sample from phosphorite deposits of Ganntour (Morocco) with the structural formula Si8(Mg2.6Al1.19Fe0.33III□0.88)Ca0.056Na0.024K0.104O20(OH)2(OH2)4⋅4H2O, was studied by FTIR spectroscopy. In both OH-stretching and OH-bending regions, there is evidence of dioctahedral Al2□OH, AlFe□OH and trioctahedral Mg3OH features ...
A. Chahi, S. Petit, A. Decarreau
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