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leonite

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Journal Article
Published: 01 March 2016
European Journal of Mineralogy (2016) 28 (1): 33–42.
...Tonči Balić-Žunić; Renie Birkedal; Anna Katerinopoulou; Paola Comodi Abstract The high-temperature behaviour of blödite (Na 2 Mg(SO 4 ) 2 (H 2 O) 4 ) and leonite (K 2 Mg(SO 4 ) 2 (H 2 O) 4 ) was studied by X-ray diffraction on powder samples in open capillaries and by thermo-gravimetry/calorimetry...
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Journal Article
Published: 01 November 2002
European Journal of Mineralogy (2002) 14 (6): 1009–1017.
...Birgit HERTWECK; Eugen LIBOWITZKY Abstract Infrared (IR) and Raman spectra of leonite-type minerals, K 2 Me(SO 4 ) 2 .4H 2 O (Me = Mg, Mn, Fe), confirm a succession of structural phase transitions between 277 and 120 K. Because the orientation and dynamic behaviour of the sulphate tetrahedra...
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Journal Article
Published: 01 October 2001
American Mineralogist (2001) 86 (10): 1282–1292.
...Birgit Hertweck; Gerald Giester; Eugen Libowitzky Abstract Recent optical and differential scanning calorimetry measurements indicate phase transitions in leonite-type compounds at low temperatures. The crystal structures of these phases, i.e., leonite, K 2 Mg(SO 4 ) 2 ·4H 2 O, “Mn-leonite”, K 2 Mn...
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Journal Article
Published: 01 February 2001
Mineralogical Magazine (2001) 65 (1): 103–109.
... analysis, scanning electron microscopy and electron microprobe. Beside thenardite (dehydration product of mirabilite) we also identified three sulphate minerals: leonite [K 2 Mg(SO 4 ) 2 ·4H 2 O], syngenite [K 2 Ca(SO 4 ) 2 ·H 2 O] and konyaite [Na 2 Mg(SO 4 ) 2 ·5H 2 O]. Of these, leonite and konyaite...
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Journal Article
Published: 01 June 1995
European Journal of Mineralogy (1995) 7 (3): 559–566.
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FTIR absorption spectra of the sulphate stretching modes in (a) <b>leonite</b>, (b...
Published: 01 November 2002
Fig. 5. FTIR absorption spectra of the sulphate stretching modes in (a) leonite, (b) “Mn-leonite”, and (c) mereiterite. Dashed lines indicate the appearance and disappearance of vibrational modes at the I 2/ a ⟷ P 2 1 / a phase transitions in leonite and “Mn-leonite”. Temperature steps
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FTIR absorption spectra of the O-H stretching modes in (a) <b>leonite</b>, (b) “Mn...
Published: 01 November 2002
Fig. 6. FTIR absorption spectra of the O-H stretching modes in (a) leonite, (b) “Mn-leonite”, and (c) mereiterite. Dashed lines indicate the appearance of additional vibrational modes at the I 2/ a ⟷ P 2 1 / a phase transitions in leonite and “Mn-leonite”. Temperature steps
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Full Width Half Maximum and peak centre of the  ν  −1  sulphate modes in Ra...
Published: 01 November 2002
Fig. 3. Full Width Half Maximum and peak centre of the ν −1 sulphate modes in Raman spectra as a function of temperature in (a) leonite, (b) “Mn-leonite”, and (c) mereiterite. Vertical dashed lines indicate the transition temperatures of the C 2/ m ⟷ I 2/ a ⟷ P 2 1 / a phase transitions
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The crystal structures of the <b>leonite</b>-type compounds in a projection along ...
Published: 01 October 2001
F igure 1. The crystal structures of the leonite-type compounds in a projection along [001]. Approximately half of the unit cell is plotted along [100]. Groups of MeO 6 octahedra with two sulfate tetrahedra are oriented nearly parallel to [100]. They are interconnected by K atoms (large
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Examples of autocorrelation analyses of Raman and FTIR absorption spectra o...
Published: 01 November 2002
Fig. 8. Examples of autocorrelation analyses of Raman and FTIR absorption spectra of leonite-type compounds. Vertical dashed lines indicate the transition temperatures of the C 2/ m ⟷ I 2/ a ⟷ P 2 1 / a phase transitions for leonite and “Mn-leonite”, and the transition temperature of the C
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Raman spectra of the sulphate  ν  3  and  ν  4  modes in <b>leonite</b>-type compo...
Published: 01 November 2002
Fig. 2. Raman spectra of the sulphate ν 3 and ν 4 modes in leonite-type compounds. Vertical lines (as a guide for the eye) indicate the appearance or disappearance, respectively, of vibrational modes at the I 2/ a ⟷ P 2 1 / a phase transitions for leonite and “Mn-leonite”. (a) Raman
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Crystal structures of (a) blödite and (b) <b>leonite</b>. Sulphate groups are colo...
Published: 01 March 2016
Fig. 1 Crystal structures of (a) blödite and (b) leonite. Sulphate groups are coloured grey, MgO 6 octahedra orange. Hydrogen atoms are represented black, Na atoms yellow and K atoms red. For the sake of clarity, for leonite an ordered low-temperature polymorph ( Hertweck et al. , 2001
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Details of the hydrogen bonds surrounding the tetrahedra in the crystal str...
Published: 01 October 2001
F igure 2. Details of the hydrogen bonds surrounding the tetrahedra in the crystal structures of leonite and “Mn-leonite”. ( a ) S o tetrahedron of the I 2/ a crystal structure ( b ) S d tetrahedron of the I 2/ a (left) and C 2/ m (right) crystal structures.
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TGA curve, the first derivative of the TGA curve, and the DSC curve for leo...
Published: 01 March 2016
Fig. 5 TGA curve, the first derivative of the TGA curve, and the DSC curve for leonite, K 2 Mg(SO 4 ) 2 (H 2 O) 4 . At the bottom are indicated the results of the X-ray diffraction analysis. The red line marks the presence of leonite and kainite whereas the blue line marks the presence
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Schematic picture of the phase transitions of the <b>leonite</b>-type compounds. T...
Published: 01 October 2001
F igure 4. Schematic picture of the phase transitions of the leonite-type compounds. The room temperature phases have a crystal structure with space group C 2/ m , the intermediate phases have a crystal structure with space group I 2/ a and the low-temperature phases have a crystal structure
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The thermal evolution of (δ ΔCorr) 2  and (δFWHM) 2  for (a) autocorrelated...
Published: 01 November 2002
Fig. 9. The thermal evolution of (δ ΔCorr) 2 and (δFWHM) 2 for (a) autocorrelated IR spectra of mereiterite in the range between 900 and 1300 cm −1 , (b) autocorrelated Raman spectra of mereiterite in the range between 1095.3 and 1159.8 cm −1 shift, (c) autocorrelated IR spectra of leonite
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FTIR absorption spectra of the sulphate bending modes of the <b>leonite</b>-type c...
Published: 01 November 2002
Fig. 4. FTIR absorption spectra of the sulphate bending modes of the leonite-type compounds in the indicated temperature ranges. Dashed lines (as a guide for the eye) indicate the appearance and disappearance of vibrational modes at the I 2/ a ⟷ P 2 1 / a phase transitions in leonite
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Platy crystal of konyaite on matrix of <b>leonite</b> and mirabilite.
Published: 01 February 2001
F ig . 3. Platy crystal of konyaite on matrix of leonite and mirabilite.
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Relative changes of the crystal lattice parameters of <b>leonite</b> (black) and k...
Published: 01 March 2016
Fig. 6 Relative changes of the crystal lattice parameters of leonite (black) and kainite (red) with temperature. The monoclinic angles show a negligible change and are omitted.
Series: Geological Society, London, Special Publications, Geological Society, London, Special Publications
Published: 01 January 2007
DOI: 10.1144/SP285.15
EISBN: 9781862395336
... zone minerals (picromerite, leonite, bloedite, syngenite and gypsum) show values ranging from +14.73‰ to +18.22‰. The recorded depletion of sulphur isotopic composition of the salt minerals of potash deposits (and their weathering zone) was probably caused by one or more of the following isotope...
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