1-20 OF 51 RESULTS FOR

leonite

Results shown limited to content with bounding coordinates.
Follow your search
Access your saved searches in your account

Would you like to receive an alert when new items match your search?
Close Modal
Sort by
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...
FIGURES | View All (7)
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...
FIGURES | View All (9)
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...
FIGURES | View All (4)
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...
FIGURES | View All (4)
Journal Article
Published: 01 June 1995
European Journal of Mineralogy (1995) 7 (3): 559–566.
Image
FTIR absorption spectra of the sulphate stretching modes in (a) <span class="search-highlight">leonite</span>, (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
Image
FTIR absorption spectra of the O-H stretching modes in (a) <span class="search-highlight">leonite</span>, (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
Image
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 <span class="search-highlight">leonite</span>-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
Image
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
Image
Raman spectra of the sulphate  ν  3  and  ν  4  modes in <span class="search-highlight">leonite</span>-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
Image
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.
Image
Crystal structures of (a) blödite and (b) <span class="search-highlight">leonite</span>. 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
Image
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
Image
Schematic picture of the phase transitions of the <span class="search-highlight">leonite</span>-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
Image
FTIR absorption spectra of the sulphate bending modes of the <span class="search-highlight">leonite</span>-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
Image
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
Image
Relative changes of the crystal lattice parameters of <span class="search-highlight">leonite</span> (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.
Image
Platy crystal of konyaite on matrix of <span class="search-highlight">leonite</span> and mirabilite.
Published: 01 February 2001
F ig . 3. Platy crystal of konyaite on matrix of leonite and mirabilite.
Journal Article
Published: 13 May 2022
Mineralogical Magazine (2022) 86 (3): 478–485.
... in the Toludskoe lava field, formed during the 2012–2013 Tolbachik fissure eruption. The mineral occurs as thin acicular transparent bright red crystals up to 0.15 mm. Medvedevite is associated with thénardite, halite, aphthitalite, leonite, kieserite, eugsterite and syngenite. The empirical formula calculated...
FIGURES | View All (7)