Unique thallium mineralization in the fumaroles of Tolbachik volcano, Kamchatka Peninsula, Russia. I. Markhininite, TlBi(SO4)2

2014 ◽  
Vol 78 (7) ◽  
pp. 1687-1698 ◽  
Author(s):  
Oleg I. Siidra ◽  
Lidiya P. Vergasova ◽  
Sergey V. Krivovichev ◽  
Yuri L. Kretser ◽  
Anatoly N. Zaitsev ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Cinder Cone ◽  
Direct Methods ◽  
Kamchatka Peninsula ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
The North ◽  
Tolbachik Volcano ◽  
Academy Of Sciences

AbstractMarkhininite, ideally TlBi(SO4)2, was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. Markhininite occurs as white pseudohexagonal plates associated with shcherbinaite, pauflerite, bobjonesite, karpovite, evdokimovite and microcrystalline Mg, Al, Fe and Na sulfates. Markhininite is triclinic, P1̄ , a = 7.378(3), b = 10.657(3), c = 10.657(3) Å , α = 61.31(3), β = 70.964(7), γ = 70.964(7)º, V = 680.2(4) Å3, Z = 4 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are (I/d/hkl): 68/4.264/111, 100/3.441/113, 35/3.350/222, 24/3.125/122, 23/3.054/202, 45/2.717/022, 20/2.217/331, 34/2.114/204. Chemical composition determined by electron microprobe analysis is (wt.%): Tl2O 35.41, Bi2O3 38.91, SO3 25.19, total 99.51. The empirical formula based on 8 O a.p.f.u. is Tl1.04Bi1.05S1.97O8. The simplified formula is TlBi(SO4)2, which requires Tl2O 35.08, Bi2O3 38.48, SO3 26.44, total 100.00 wt.%. The crystal structure was solved by direct methods and refined to R1 = 0.055 on the basis of 1425 independent observed reflections. The structure contains four Tl+ and two Bi3+ sites in holodirected symmetrical coordination. BiO8 tetragonal antiprisms and SO4 tetrahedra in markhininite share common O atoms to produce [Bi(SO4)2]– layers of the yavapaiite type. The layers are parallel to (111) and linked together through interlayer Tl+ cations. The mineral is named in honour of Professor Yevgeniy Konstantinovich Markhinin (b. 1926), Institute of Volcanology, Russian Academy of Sciences, Kamchatka peninsula, Russia, in recognition of his contributions to volcanology. Markhininite is the first oxysalt compound that contains both Tl and Bi in an ordered crystal structure.

Unique thallium mineralization in the fumaroles of the Tolbachik volcano, Kamchatka Peninsula, Russia. II. Karpovite, Tl2VO(SO4)2(H2O)

2014 ◽  
Vol 78 (7) ◽  
pp. 1699-1709 ◽  
Author(s):  
Oleg I. Siidra ◽  
Lidiya P. Vergasova ◽  
Yuri L. Kretser ◽  
Yuri S. Polekhovsky ◽  
Stanislav K. Filatov ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Cinder Cone ◽  
Direct Methods ◽  
Kamchatka Peninsula ◽  
Dimensional Structure ◽  
New Mineral ◽  
The North ◽  
Tolbachik Volcano ◽  
Oriented Parallel ◽  
Academy Of Sciences

AbstractKarpovite, ideally Tl2VO(SO4)2(H2O), was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption (1975–1976), Kamchatka Peninsula, Russia. Karpovite occurs as bundles of white, needle-like crystals associated with shcherbinaite, pauflerite, bobjonesite, markhininite, evdokimovite and microcrystalline Mg, Al, Fe and Na sulfates. Karpovite is monoclinic, P21, a = 4.6524(4), b = 11.0757(9), c = 9.3876(7) Å , β = 98.353(2)º, V = 478.60(7) Å3, Z = 2 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are (I/d/hkl): 64/4.289/012, 81/4.253/110, 38/3.683/111, 47/3.557/022, 100/3.438/1̄21, 52/2.982/013, 59/2.945/112, 54/2.354/132. The chemical composition determined by the electron microprobe analysis is (wt.%) Tl2O 61.43, VO2 11.53, SO3 23.55, H2O 2.61, total 99.12. The empirical formula (calculated on the basis of 10 O a.p.f.u.) is Tl2.00V0.96S2.03O9(H2O). The simplified formula of karpovite is Tl2VO(SO4)2(H2O), which requires Tl2O 61.93, VO2 12.09, SO3 23.34, H2O 2.62 total 100.00 wt.%. The crystal structure was solved by direct methods and refined to R1 = 0.026 for 4196 independent observed reflections. The structure contains two symmetrically independent Tl+ sites, one V4+ site and two S6+ sites. VO5H2O octahedra and SO4 tetrahedra link together by sharing corners to form kröhnkite-type stripes parallel to the a axis with their planes oriented parallel to (021) and (021̄ ). Tl+ cations are located between the chains, linked into a three-dimensional structure. The new mineral is named in honour of Professor Gennadii Alexandrovich Karpov (b. 1938), volcanologist at the Institute of Volcanology, Russian Academy of Sciences, Petropavlovsk-Kamchatskii, Kamchatka Peninsula, Russia.

Unique thallium mineralization in the fumaroles of Tolbachik volcano, Kamchatka Peninsula, Russia. III. Evdokimovite, Tl4(VO)3(SO4)5(H2O)5

2014 ◽  
Vol 78 (7) ◽  
pp. 1711-1724 ◽  
Author(s):  
Oleg I. Siidra ◽  
Lidiya P. Vergasova ◽  
Yuri L. Kretser ◽  
Yuri S. Polekhovsky ◽  
Stanislav K. Filatov ◽  
...  
Keyword(s):  
Structural Information ◽  
Cinder Cone ◽  
Direct Methods ◽  
Kamchatka Peninsula ◽  
New Mineral ◽  
State University ◽  
X Ray Diffraction ◽  
The North ◽  
Tolbachik Volcano ◽  
The University

AbstractEvdokimovite, ideally Tl4(VO)3(SO4)5(H2O)5, was found in a fumarole of the 1st cinder cone of the North Breach of the Great Fissure Tolbachik volcano eruption of 1975–1976, Kamchatka Peninsula, Russia. Evdokimovite occurs as thin, colourless needles up to 0.09 mm long associated with shcherbinaite, pauflerite, bobjonesite, markhininite, karpovite and microcrystalline Mg, Al, Fe and Na sulfates. Evdokimovite is monoclinic, P21/n, a = 6.2958(14), b = 10.110(2), c = 39.426(11) Å , β = 90.347(6)º, V = 2509.4(10) Å3 and Z = 4 (from single-crystal diffraction data). The eight strongest lines of the powder X-ray diffraction pattern are (I/d/hkl): 57/9.793/011, 100/8.014/013, 26/6.580/006, 19/ 4.011/026, 29/3.621/118, 44/3.522/125, 19/3.010/036, 21/2.974/212. Chemical composition determined by the electron microprobe analysis is (wt.%): Tl2O 55.40, VO2 14.92, SO3 25.83, H2O 5.75, total 101.90. The empirical formula for evdokimovite calculated on the basis of (Tl + V + S) = 12 a.p.f.u. is Tl4.10V2.83S5.07H10.00O27.94. The simplified formula is Tl4(VO)3(SO4)5(H2O)5. The crystal structure was solved by direct methods and refined to R1 = 0.11 on the basis of 3660 independent observed reflections. V4+O6 octahedra and SO4 tetrahedra share common corners to form two types of vanadyl-sulfate chains, [(VO)(H2O)2(SO4)2]2– and [(VO)2(H2O)3(SO4)3]2–. Thallium atoms are located in between the chains. The structure can be described as a stacking of layers of two types, A and B. The A layer contains [(VO)2(H2O)3(SO4)3]2– chains and the Tl2 and Tl3 atoms, whereas the B layer contains [(VO)(H2O)2(SO4)2]2– chains and the Tl1 atoms. Stacking of the layers can be described as ...A’*BAA’B*A*..., where A and A’ denote A layers with opposite orientations of the [(VO)2(H2O)3(SO4)3]2– chains, and the A* and B* layers are rotated by 180º relative to the A and B layers, respectively. [(VO)2(H2O)3(SO4)3]2– chains are modulated and are arranged to form elliptical tunnels hosting disordered Tl(4), Tl(4A) and Tl(4B) sites. The new mineral is named in honour of Professor Mikhail Dmitrievich Evdokimov (1940–2010), formerly of the Department of Mineralogy, St Petersburg State University, for his contributions to mineralogy and petrology, and especially for teaching mineralogy to several generations of students at the University. Evdokimovite is the most complex V4+ sulfate known to date with structural information amounting to 1130 bits per unit cell, which places evdokimovite among minerals with the complexity of the vesuvianite group.

Itelmenite, Na2CuMg2(SO4)4, a new anhydrous sulfate mineral from the Tolbachik volcano

2018 ◽  
Vol 82 (6) ◽  
pp. 1233-1241 ◽  
Author(s):  
Evgeny V. Nazarchuk ◽  
Oleg I. Siidra ◽  
Atali A. Agakhanov ◽  
Evgeniya A. Lukina ◽  
Evgeniya Y. Avdontseva ◽  
...  
Keyword(s):  
Direct Methods ◽  
Structural Data ◽  
Kamchatka Peninsula ◽  
Scoria Cone ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
Unique Type ◽  
X Ray ◽  
Tolbachik Volcano ◽  
Heteropolyhedral Framework

ABSTRACTItelmenite, ideally Na2CuMg2(SO4)4, was found in a fumarole of the Naboko scoria cone of the Tolbachik volcano Fissure Eruption (2012–2013), Kamchatka Peninsula, Russia. Itelmenite occurs as irregularly shaped grains as well as microcrystalline masses associated with anhydrite, saranchinaite, hermannjahnite, euchlorine, thénardite, aphthitalite and hematite. Itelmenite is orthorhombic, Pbca, a = 9.568(2) Å, b = 8.790(2) Å, c = 28.715(8) Å, V = 2415.0(11) Å3 and Z = 4 (from single-crystal diffraction data). The nine strongest lines of the powder X-ray diffraction pattern are [d(I)(hkl)]: 7.9614(41)(102), 7.1803(32)(004), 5.9122(64)(112), 3.8455(87)(122), 3.6292(52)(214), 3.3931(62)(215), 3.0003(44)(027), 2.9388(100)(312) and 2.4975(56)(230). The chemical composition determined by the electron-microprobe analysis is (wt.%): Na2O 10.77, K2O 0.20, MgO 11.10, CuO 15.38, ZnO 5.61, SO3 56.42, total 99.48. The empirical formula based on O = 32 apfu is (Na3.93K0.05)Σ3.98Mg3.12(Cu2.19Zn0.78)Σ2.97S7.97O32. The simplified formula is Na2CuMg2(SO4)4 taking into account structural data. The crystal structure was solved by direct methods and refined to an agreement index R1 = 0.034 on the basis of 1855 independent observed reflections. The structure of itelmenite is based on a unique type of [A2+3(SO4)4]2– (A = Mg, Cu and Zn) heteropolyhedral framework with voids filled by Na+ cations.

X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

1998 ◽  
Vol 54 (4) ◽  
pp. 358-364 ◽  
Author(s):  
K. G. Hatzisymeon ◽  
S. C. Kokkou ◽  
A. N. Anagnostopoulos ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

Structure of Pb-rich chabournéite from Jas Roux, France

2015 ◽  
Vol 71 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Cristian Biagioni ◽  
Yves Moëlo ◽  
Georges Favreau ◽  
Vincent Bourgoin ◽  
Jean-Claude Boulliard
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Structural Formula ◽  
Unit Cell ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Cation Sites ◽  
Pyramidal Groups

The crystal structure of a specimen of `Pb-rich' chabournéite from Jas Roux, Hautes-Alpes, France, with the chemical formula obtained by electron microprobe analysis of Ag0.04 (1)Tl2.15 (2)Pb0.64 (1)Sb5.12 (1)As5.05 (1)S17.32 (5), has been solved by X-ray single-crystal diffraction on the basis of 36 550 observed reflections (withFo> 4σFo) with a finalR1= 0.074. Pb-rich chabournéite is triclinicP1, with unit-cell parametersa= 8.5197 (4),b= 42.461 (2),c= 16.293 (8) Å, α = 83.351 (2), β = 90.958 (2), γ = 84.275 (2)°,V= 5823 (3) Å3. Its structural formula is close to [Tl2(Pb0.8Tl0.1Sb1.1)](Sb4.1As4.9)S17, withZ= 8. Its crystal structure is formed by the alternation of two pairs of slabs along thebaxis, deriving from the SnS and PbS archetypes, respectively. 104 independent cation sites and 136 S sites occur in the unit cell. Slab interfaces show the alternation, alongc, of Tl sites, ninefold coordinated, with Pb, Sb or mixed/split (Pb,Sb) and (Pb,Tl) sites. Within the slabs, 72 independentM3+sites (M3+= As, Sb) occur. ConsideringM3+—S bond distances shorter than 2.70 Å,MS3triangular pyramidal groups are condensed according to variousMmSnchain fragments (`polymers'). The solution of the crystal structure of chabournéite allows its comparison with the closely related homeotypes protochabournéite and dalnegroite.

The new mineral novograblenovite, (NH4,K)MgCl3·6H2O from the Tolbachik volcano, Kamchatka, Russia: mineral description and crystal structure

2018 ◽  
Vol 83 (02) ◽  
pp. 223-231 ◽  
Author(s):  
Viktor M. Okrugin ◽  
Sharapat S. Kudaeva ◽  
Oxana V. Karimova ◽  
Olga V. Yakubovich ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Structure Refinement ◽  
Kamchatka Peninsula ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Tolbachik Volcano ◽  
Difference Fourier

AbstractThe new mineral novograblenovite, (NH4,K)MgCl3·6H2O, was found on basaltic lava from the 2012–2013 Tolbachik fissure eruption at the Plosky Tolbachik volcano, Kamchatka Peninsula, Russia. It occurs as prismatic, needle-like transparent crystals together with gypsum and halite. Novograblenovite was formed due to the exposure of the host rocks to eruptive gas exhalations enriched in HCl and NH3. Basalt was the source of potassium and magnesium for the mineral formation. Novograblenovite crystallises in the monoclinic space group C2/c, with unit-cell parameters a = 9.2734(3) Å, b = 9.5176(3) Å, c = 13.2439(4) Å, β = 90.187(2)°, V = 1168.91(2) Å3 and Z = 4. The five strongest reflections in the powder X-ray diffraction pattern [dobs, Å (I, %) (h k l)] are: 3.330 (100) (2 2 0), 2.976 (45) ($\bar{1}\; 1\; 4$), 2.353 (29) ($\bar {2}\; 2\; 4$), 3.825 (26) (2 0 2), 1.997 (25) ($\overline {4\; 2} $ 2). The density calculated from the empirical formula and the X-ray data is 1.504 g cm–3. The mineral is biaxial (+) with α = 1.469(2), β = 1.479(2) and γ = 1.496(2) (λ = 589 nm); 2Vmeas. = 80(10)° and 2Vcalc. = 75.7°. The crystal structure (solved and refined using single-crystal X-ray diffraction data, R1 = 0.0423) is based on the perovskite-like network of (NH4,K)Cl6-octahedra sharing chlorine vertices, and comprises [Mg(H2O)6]2+ groups in framework channels. The positions of all independent H atoms were obtained by difference-Fourier techniques and refined isotropically. All oxygen, nitrogen and chlorine atoms are involved in the system of hydrogen bonding, acting as donors or acceptors. The formula resulting from the structure refinement is [(NH4)0.7K0.3]MgCl3·6H2O. The mineral is named after Prokopiy Trifonovich Novograblenov, one of the researchers of Kamchatka Peninsula, a teacher, naturalist, geographer and geologist.

Glikinite, Zn3O(SO4)2, a new anhydrous zinc oxysulfate mineral structurally based on OZn4 tetrahedra.

2020 ◽  
Vol 84 (4) ◽  
pp. 563-567 ◽  
Author(s):  
Evgeny V. Nazarchuk ◽  
Oleg I. Siidra ◽  
Diana O. Nekrasova ◽  
Vladimir V. Shilovskikh ◽  
Artem S. Borisov ◽  
...  
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Kamchatka Peninsula ◽  
Scoria Cone ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Assemblages ◽  
Tolbachik Volcano ◽  
3D Framework

AbstractA new mineral glikinite, ideally Zn3O(SO4)2, was found in high-temperature exhalative mineral assemblages in the Arsenatnaya fumarole, Second scoria cone of the Great Tolbachik Fissure Eruption (1975–1976), Tolbachik volcano, Kamchatka Peninsula, Russia. Glikinite is associated closely with langbeinite, lammerite-β, bradaczekite, euchlorine, anhydrite, chalcocyanite and tenorite. It is monoclinic, P21/m, a = 7.298(18), b = 6.588(11), c = 7.840(12) Å, β = 117.15(3)°, V = 335.4(11) Å3 and R1 = 0.046. The eight strongest lines of the powder X-ray diffraction pattern [d in Å (I) (hkl)] are: 6.969(56)(00$\bar{1}$), 3.942(52)(101), 3.483(100)(00$\bar{2}$), 3.294(49)(020), 2.936(43)(120), 2.534(63)(201), 2.501(63)(20$\bar{3}$) and 2.395(86)(02$\bar{2}$). The chemical composition determined by electron-microprobe analysis is (wt.%): ZnO 42.47, CuO 19.50, SO3 39.96, total 101.93. The empirical formula calculated on the basis of O = 9 apfu is Zn2.07Cu0.97S1.98O9 and the simplified formula is Zn3O(SO4)2. Glikinite is a Zn,Cu analogue of synthetic Zn3O(SO4)2. The crystal structure of glikinite is based on OZn4 tetrahedra sharing common corners, thus forming [Zn3O]4+ chains. Sulfate groups interconnect [Zn3O]4+ chains into a 3D framework.

The crystal structure of kiddcreekite solved using micro X-ray diffraction and the EPCryst program

2014 ◽  
Vol 78 (7) ◽  
pp. 1517-1525 ◽  
Author(s):  
Liu Wenyuan ◽  
Dong Cheng ◽  
Gu Xiangping ◽  
Liu Yu ◽  
Qiu Xiaoping ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Rietveld Method ◽  
Lattice Parameter ◽  
X Ray Diffraction ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Covellite Ore ◽  
Space Method

AbstractAbundant kiddcreekite grains were identified in the Zijinshan Cu-Au epithermal deposit in Fujian Province, China. The mineral occurs as polycrystalline grains, 5–300 μm in size, associated with colusite, enargite, stannoidite, mawsonite, vinciennite, hemusite, tennantite and wolframite in a predominantly covellite ore. Based on electron microprobe analysis, the empirical formula of the kiddcreekite is Cu6.2Sn0.97W0.95S7.83, without significant Se or Te contents. The crystal structure of kiddcreekite was solved using the direct-space method (EPCryst) from laboratory micro X-ray diffraction (μXRD) data and refined by the Rietveld method. The R values of the final Rietveld refinement were Rp = 9.06%, Rwp = 8.31%, RB = 3.16 and RF = 2.17%. Kiddcreekite has a cubic structure, space group F4̄3m and lattice parameter a = 10.8178(3) Å (Z = 4, V = 1265.95(6) Å3). In the unit cell, W, Sn and Cu atoms occupy the 4a, 4c and 24f Wyckoff positions, respectively, and S atoms occupy two sets of 16e Wyckoff positions. The structure of kiddcreekite consists of stacked double MeS4 layers (giving a W–Sn–Cu tier and a Cu–vacancy tier) as in the sphalerite substructure. This study also demonstrates the possibility of using laboratory µXRD data coupled with the direct-space method to solve inorganic structures in cases where samples are too small for conventional powder and single-crystal diffraction.

Crystal structure of Ba8[Al3O10][AlO4], a novel mixed-anion Ba aluminate related to kilchoanite

2001 ◽  
Vol 65 (4) ◽  
pp. 533-541 ◽  
Author(s):  
V. Kahlenberg
Keyword(s):  
Crystal Structure ◽  
Crystal Growth ◽  
Diffraction Data ◽  
Direct Methods ◽  
Fourier Synthesis ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Difference Fourier ◽  
Growth Experiments

AbstractCrystal growth experiments in the system BaO–Al2O3yielded single crystals of a new Ba oxo-aluminate with composition Ba4Al2O7. The title compound is orthorhombic, with cell parametersa= 11.3126(5),b= 11.7045(9),c= 27.1850(14) Å, space groupCmca. The structure was solved by direct methods followed by difference Fourier synthesis from X-ray single crystal diffraction data (R1 = 0.048 for 1213 independent observed reflections and 135 parameters). The main building units of tetrabarium aluminate are Al3O10trimers and isolated AlO4tetrahedra. Seven crystallographically different Ba sites crosslink between the tetrahedral groups and are co-ordinated by six to nine oxygen ligands. The structure is closely related to the mineral kilchoanite (Ca6[SiO4][Si3O10]) and the first representative of an unbranched oligo-aluminate with triple tetrahedra.

Belousovite, KZn(SO4)Cl, a new sulfate mineral from the Tolbachik volcano with apophyllite sheet-topology.

2018 ◽  
Vol 82 (5) ◽  
pp. 1079-1088 ◽  
Author(s):  
Oleg I. Siidra ◽  
Evgeny V. Nazarchuk ◽  
Evgeniya A. Lukina ◽  
Anatoly N. Zaitsev ◽  
Vladimir V. Shilovskikh
Keyword(s):  
Inorganic Compounds ◽  
Direct Methods ◽  
Kamchatka Peninsula ◽  
Scoria Cone ◽  
Mixed Ligand ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
The North ◽  
Tolbachik Volcano ◽  
Group A

ABSTRACTBelousovite, ideally KZn(SO4)Cl, was found in a Yadovitaya fumarole of the Second scoria cone of the North Breach of the Great Tolbachik Fissure Eruption (1975–1976), Tolbachik volcano, Kamchatka Peninsula, Russia. Belousovite occurs as irregularly-shaped grains and in the form of microcrystalline masses associated with kamchatkite, langbeinite, euchlorine, anglesite and zincite. Belousovite is monoclinic, P21/c, a = 6.8904(5), b = 9.6115(7), c = 8.2144(6) Å, β = 96.582(2), V = 540.43(7) Å3 and Z = 4 (from single-crystal diffraction data). The eight strongest lines of the powder X-ray diffraction pattern are [dmeas Å(I)(hkl)]: 6.8451(100)(100), (3.6401)(71)($\bar{1}$21), (3.1592)(84)(1$\bar{1}$2), (3.1218)(41)($\bar{2}$11), (3.1140)(52)(022), (2.9812)(41)(031), (2.9121)(44)(130) and (2.0483)(19)($\bar{3}$12). The chemical composition determined by the electron-microprobe analysis is (wt.%): K2O 19.55, Rb2O 0.58, ZnO 34.85, SO3 34.65, Cl 14.77, –O = Cl2 3.34, total 101.06. The empirical formula based on O + Cl = 5 apfu is K0.97Rb0.01Zn1.00S1.01O4.03Cl0.97. The simplified formula is KZn(SO4)Cl. The crystal structure was solved by direct methods and refined to R1 = 0.029 on the basis of 1965 independent observed reflections. The structure of belousovite consists of infinite [ZnSO4Cl]– layers and K+ ions. [ZnSO4Cl]– layers are formed by corner sharing mixed-ligand ZnO3Cl tetrahedra and SO4 tetrahedra. The topology of [ZnSO4Cl]– layers in belousovite is identical to [Si4O10]4– layers in the minerals of the apophyllite group. A review of mixed-ligand ZnOmCln coordination polyhedra in minerals and inorganic compounds is given.

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