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leonite

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Journal Article

Dehydration of blödite, Na 2 Mg(SO 4 ) 2 (H 2 O) 4 , and leonite, K 2 Mg(SO 4 ) 2 (H 2 O) 4

Tonči Balić-Žunić, Renie Birkedal, Anna Katerinopoulou, Paola Comodi
Published: 01 March 2016
European Journal of Mineralogy (2016) 28 (1): 33–42.
DOI: https://doi.org/10.1127/ejm/2015/0027-2487
...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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Vibrational spectroscopy of phase transitions in leonite-type minerals

Birgit HERTWECK, Eugen LIBOWITZKY
Published: 01 November 2002
European Journal of Mineralogy (2002) 14 (6): 1009–1017.
DOI: https://doi.org/10.1127/0935-1221/2002/0014-1009
...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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The crystal structures of the low-temperature phases of leonite-type compounds, K 2 Me(SO 4 ) 2 ·4H 2 O (Me 2+ = Mg, Mn, Fe)

Birgit Hertweck, Gerald Giester, Eugen Libowitzky
Published: 01 October 2001
American Mineralogist (2001) 86 (10): 1282–1292.
DOI: https://doi.org/10.2138/am-2001-1016
...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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Leonite [K 2 Mg(SO 4 ) 2 · 4 H 2 O], konyaite [Na 2 Mg(SO 4 ) 2 · 5 H 2 O] and syngenite [K 2 Ca(SO 4 ) 2 ·H 2 O] from Tausoare Cave, Rodnei Mts, Romania

B. P. Onac, W. B. White, I. Viehmann
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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Mereiterite, K 2 Fe[SO 4 ] 2 .4H 2 O, a new leonite-type mineral from the Lavrion mining district, Greece

Gerald Giester, Branko Rieck
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...

FTIR absorption spectra of the sulphate stretching modes in (a) leonite, (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...

FTIR absorption spectra of the O-H stretching modes in (a) leonite, (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...

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
Image
The crystal structures of the <b>leonite</b>-type compounds in a projection along ...

The crystal structures of the leonite-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...

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...

Raman spectra of the sulphate ν 3 and ν 4 modes in leonite-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...

Crystal structures of (a) blödite and (b) leonite. 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...

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...

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...

Schematic picture of the phase transitions of the leonite-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...

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...

FTIR absorption spectra of the sulphate bending modes of the leonite-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.

Platy crystal of konyaite on matrix of leonite 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...

Relative changes of the crystal lattice parameters of leonite (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.
Book Chapter

Sulphur isotopic composition of K–Mg sulphates of the Miocene evaporites of the Carpathian Foredeep, Ukraine

Author(s)
S. Hryniv, J. Parafiniuk, T. M. Peryt
Book: Evaporites Through Space and Time
Series: Geological Society, London, Special Publications, Geological Society, London, Special Publications
Publisher: Geological Society of London
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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Abstract Miocene evaporites of the Carpathian Foredeep host an interesting sulphates group of potash deposits, including about 20 sulphates minerals. The study of sulphur isotopic composition of 10 of the sulphates minerals from the Kalush–Holyh and Stebnyk potash deposits shows that only the basal Ca-sulphates (anhydrite) from the Kalush–Holyn potash deposits has δ 34 S values typical of Neogene marine evaporites (+21.0‰). Potash minerals related to the deposits (polyhalite, anhydrite, kainite, langbeinite and kieserite) show δ 34 S values from +15.28‰ to +17.54‰, and the weathering 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 fractionation factors: bacterial reduction of sulphate, effect of crystallization and inflow of surface waters containing sulphates enriched in light sulphur isotopes due to pyrite oxidation. Accordingly, the observed sulphur isotopic composition of minerals from these potash deposits demonstrates the depletion of the original brines and continual inflow of new (concentrated) seawater. Similar sulphur isotopic composition of minerals from the potash deposits and their weathering zone points out that there was no significant sulphur isotope fractionation during weathering and in this case inflow of surface water has an insignificant influence on sulphur isotopic composition.