| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Shablinskii, Andrey
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (7/7 displayed)
- 2023Galeite, Na15(SO4)5ClF4, and Schairerite, Na21(SO4)7ClF6: Phase Transitions, Thermal Expansion and Thermal Stabilitycitations
- 2023Novel Red-Emitting BaBi2B4O10:Eu3+ Phosphors: Synthesis, Crystal Structure and Luminescencecitations
- 2022Medvedevite, KMn<sup>2+</sup>V<sup>5+</sup><sub>2</sub>O<sub>6</sub>Cl⋅2H<sub>2</sub>O, a new fumarolic mineral from the Tolbachik fissure eruption 2012–2013, Kamchatka Peninsula, Russiacitations
- 2022X-ray diffraction and Mössbauer spectroscopy study of oxoborate azoproite (Mg,Fe<sup>2+</sup>)<sub>2</sub>(Fe<sup>3+</sup>,Ti,Mg,Al)O<sub>2</sub>(BO<sub>3</sub>): an <i>in situ</i> temperature-dependent investigation (5 ≤ <i>T</i> ≤ 1650 K)citations
- 2021Low-temperature investigation of natural iron-rich oxoborates vonsenite and hulsite: thermal deformations of crystal structure, strong negative thermal expansion and cascades of magnetic transitionscitations
- 2021Dobrovolskyite, Na<sub>4</sub>Ca(SO<sub>4</sub>)<sub>3</sub>, a new fumarolic sulfate from the Great Tolbachik fissure eruption, Kamchatka Peninsula, Russiacitations
- 2020Investigation of thermal behavior of mixed-valent iron borates vonsenite and hulsite containing [OM 4] n + and [OM 5] n + oxocentred polyhedra by in situ high-temperature Mössbauer spectroscopy, X-ray diffraction and thermal analysiscitations
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article
Dobrovolskyite, Na<sub>4</sub>Ca(SO<sub>4</sub>)<sub>3</sub>, a new fumarolic sulfate from the Great Tolbachik fissure eruption, Kamchatka Peninsula, Russia
Abstract
<jats:title>Abstract</jats:title><jats:p>Dobrovolskyite, Na<jats:sub>4</jats:sub>Ca(SO<jats:sub>4</jats:sub>)<jats:sub>3</jats:sub>, is a new sulfate mineral from the Great Tolbachik fissure eruption, Kamchatka peninsula, Russia. It occurs as aggregates of tabular crystals up to 1–2 mm in maximum dimension, with abundant gas inclusions. The empirical formula calculated on the basis of O = 12 is (Na<jats:sub>3.90</jats:sub>K<jats:sub>0.10</jats:sub>)<jats:sub>Σ4</jats:sub>(Ca<jats:sub>0.45</jats:sub>Mg<jats:sub>0.16</jats:sub>Cu<jats:sub>0.12</jats:sub>Na<jats:sub>0.10</jats:sub>)<jats:sub>Σ0.83</jats:sub>S<jats:sub>3.08</jats:sub>O<jats:sub>12</jats:sub>. The crystal structure of dobrovolskyite was determined using single-crystal X-ray diffraction data as: trigonal, <jats:italic>R</jats:italic>3, <jats:italic>a</jats:italic> = 15.7223(2), <jats:italic>c</jats:italic> = 22.0160(5) Å, <jats:italic>V</jats:italic> = 4713.1(2) Å<jats:sup>3</jats:sup>, <jats:italic>Z</jats:italic> = 18 and <jats:italic>R</jats:italic><jats:sub>1</jats:sub> = 0.072. The Mohs’ hardness is 3.5. The mineral is uniaxial (+), with ω = 1.489(2) and ɛ = 1.491(2) (λ = 589 nm). The seven strongest lines of the powder X-ray diffraction pattern [<jats:italic>d</jats:italic>, Å (<jats:italic>I</jats:italic>, %)(<jats:italic>hkl</jats:italic>)] are: 11.58(40)(101); 5.79(22)(202); 4.54(18)(030); 3.86(88)(033); 3.67(32)(006); 2.855(50)(306); and 2.682(100)(330). The mineral is named in honour of Prof. Dr. Vladimir Vitalievich Dolivo-Dobrovolsky (1927–2009), one of the leading Russian scientists in the field of petrology, crystal optics and crystal chemistry. The crystal structure of dobrovolskyite can be described as composed of three symmetrically independent rods running parallel to the <jats:italic>c</jats:italic> axis. The rods consist of six octahedral–tetrahedral [Na(SO<jats:sub>4</jats:sub>)<jats:sub>6</jats:sub>]<jats:sup>11–</jats:sup> or [Ca(SO<jats:sub>4</jats:sub>)<jats:sub>6</jats:sub>]<jats:sup>10–</jats:sup> clusters of central octahedra sharing common corners with six adjacent SO<jats:sub>4</jats:sub> tetrahedra. Alternatively, the crystal structure of the mineral can be described as a 12-layer <jats:bold>ABACABACABAC</jats:bold> eutactic array of Na<jats:sup>+</jats:sup> and Ca<jats:sup>2+</jats:sup> cations, and vacancies with disordered (SO<jats:sub>4</jats:sub>) tetrahedra in interstices. Dobrovolskyite and similar minerals probably formed upon cooling of a high-temperature phase with disordered cation and anion arrangements.</jats:p>