Influence of Al Substitution and Crystal Size on the Room-Temperature Mössbauer Spectrum of HematiteCambridge University Press (CUP) - Tập 34 - Trang 1-6 - 1986
Enver Murad, Udo Schwertmann
Mössbauer spectra of 15 hematites with Al substitutions between 0 and 10 mole % were taken at room temperature. X-ray powder diffraction indicated dimensions of these hematites in the c-direction to range upwards from 27 nm to crystals large enough to show no line broadening. The Mössbauer spectra showed that magnetic hyperfine fields decreased both with increasing Al-for-Fe substitution and with ...... hiện toàn bộ
Diagenetic reorientation of phyllosilicate minerals in Paleogene mudstones of the Podhale Basin, southern PolandCambridge University Press (CUP) - Tập 56 - Trang 100-111 - 2008
Ruarri J. Day-Stirrat, Andrew C. Aplin, Jan Środoń, Ben A. van der Pluijm
We used high-resolution X-ray texture goniometry to quantify changes in the mm-scale orientation of phyllosilicate minerals in a suite of Paleogene mudstones from the Podhale Basin in southern Poland. The sample set covers an estimated range of burial depths between 2.4 and 7.0 km, corresponding to a temperature range of 60–160°C. Although mechanical compaction has reduced porosities to ∼10% in th...... hiện toàn bộ
Electron Microscopy as a Method of Identifying ClaysCambridge University Press (CUP) - Tập 1 - Trang 130-150 - 1952
Thomas F. Bates
Electron microscope studies show that most of the clay minerals have morphological characteristics which can be effectively used to aid in their identification. In addition, detailed studies at high magnification have provided structural information not obtainable by other means. In the kaolinite group each of the common minerals has a clear-cut and diagnostic morphology. However, much more work i...... hiện toàn bộ
Lithium-Bearing Donbassite and Tosudite from Echassières, Massif Central, FranceCambridge University Press (CUP) - - 1988
Thierry Merceron, Atsuyuki Inoue, A Bouchet, Alain Meunier
AbstractLithium-bearing donbassite and tosudite were found in veins in hydrothermally altered granite (Beauvoir granite) in the northern part of the Massif Central, France. The two minerals are characterized by their high Li contents and low Mg and Fe contents; their structural formulae are: $${\left( {S{i_{3.8...... hiện toàn bộ
Thermal Reactions of Synthetic HectoriteCambridge University Press (CUP) - Tập 18 - Trang 339-346 - 1970
J. M. Green, K. J. D. Mackenzie, J. H. Sharp
The thermal reaction sequence of a synthetic hectorite (Laponite CP) was studied by X-ray diffraction, i.r. spectroscopy and thermal analysis. Although most of the interlayer water is removed at 200°C, a smally steady weight loss occurs until dehydroxylation is complete at about 700°C, indicating that an anhydrous intermediate phase is not formed prior to dehydroxylation. Immediately after dehydro...... hiện toàn bộ
NaOH Dissolution of Some Oxide Impurities from KaolinsCambridge University Press (CUP) - Tập 12 - Trang 633-647 - 1963
R. B. Langston, E. A. Jenne
A working definition for allophane includes amorphous silica and alumina that are quickly soluble in boiling n/2 NaOH. Kinetic studies are used to differentiate and to make a rough estimation of the amount of allophane and certain other impurities present in some kaolin minerals. Solution rate studies on opal, gibbsite, two allophanes, volcanic ash, quartz, two halloysites, and two kaolinites are ...... hiện toàn bộ