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![Columns of OBi 4 edge-sharing tetrahedra in the crystal structure of leguernite. (a) Projection along [010] showing cross-like portions formed by five rows of edge-sharing tetrahedral chains; (b) infinite [010] columns of edge-sharing tetrahedral chains and isolated tetrahedra in the layer [Bi 12 O 14 (SO 4 ) 6+ ] n .](profile/Luca-Bindi/publication/273961759/figure/fig5/AS:614141203062791@1523434081343/Columns-of-OBi-4-edge-sharing-tetrahedra-in-the-crystal-structure-of-leguernite-a.png)
Columns of OBi 4 edge-sharing tetrahedra in the crystal structure of leguernite. (a) Projection along [010] showing cross-like portions formed by five rows of edge-sharing tetrahedral chains; (b) infinite [010] columns of edge-sharing tetrahedral chains and isolated tetrahedra in the layer [Bi 12 O 14 (SO 4 ) 6+ ] n .
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![FIG. 4. A projection along [010] showing BiÀO blocks with composition...](profile/Luca-Bindi/publication/273961759/figure/fig4/AS:614141203079168@1523434081108/A-projection-along-010-showing-BiAO-blocks-with-composition-Bi-12-O-14-8-and-SO-4_Q320.jpg)
Leguernite, ideally Bi12.67O14(SO4)5, is a new mineral found in high-temperature fumarolic assemblages at La Fossa crater, Vulcano, Aeolian Islands, Italy. It occurs as aggregates of needle-shaped crystals associated strictly with anglesite,
balićžunićite and an unknown Bi sulfate. Leguernite is colourless to white, transparent, non-fluorescent, ha...
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Context 1
... Bi(7) (Wyckoff position 1a and 1b, respec- tively) and hence joined to each other by isolated sulfate tetrahedra around S(3) along [100], and by Bi(SO 4 ) 4 5À groups along [101] and [1 ¯ 01] (Fig. 4). The Bi(SO 4 ) 4 5À group, which is formed by Bi (7), and the four SO 4 -tetrahedra around S1 and S2, extend within a plane parallel to (001) (Fig. ...
Context 2
... crystal structure of leguernite is built up of blocks of Bi and O atoms extending infinitely in the b direction, but separated from each other in the a and c directions (Fig. 4) 8+ ] n , by including the four additional 'non-fluorite' oxygen atoms (Fig. 5b). Adjacent columns are related by the 2-fold axes passing through S(3) TABLE 3. Summary of parameters describing data collection and refinement for ...
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Kristjánite, KNa 2 H(SO 4 ) 2 , is a new mineral (IMA2022–131) found in a high-temperature fumarole on Fimmvörðuháls, Iceland. It is monoclinic, P 2 1 /n , a = 6.9625(1), b = 9.9953(1), c = 11.0928(2) (Å), β = 105.637(2)° and V = 743.40(2) Å ³ . Kristjánite forms colourless transparent crystals up to ~100 μm in size in compact aggregates with metat...
Citations
... Among the Russian objects of study we must point out as being also remarkable in the mineralogical context the fumaroles of Kudryavyi volcano, Kurile island arc, Russia, which show rhenium miner-alization (Korzhinsky et al., 1994;Chaplygin, 2009;Znamensky, 2005) and Mutnovsky, Kamchatka, Russia where rather original phases with Cd, Bi, Pb, Tl, and As were found as essential elements (Zelenski and Bortnikova, 2005). A considerable number of new minerals of the fumarolic formation were discovered during recent decades on Mount Vulcano on Liparian Islands, Italy; the researchers noted that the ammonium mineralization of this volcano is unique Garavelli et al., 2014;Demartin et al., 2015Demartin et al., , 2019. One of the very carefully examined features in the world as to fumarolic mineralization is Mount Vesuvius, Campania, Italy where the discovery of new mineral species goes on (Demartin et al., 2014;Rossi et al., 2014;Campostrini et al., 2019). ...
The phase composition of salt mixtures obtained by evaporation of pore solutions of clays formed in the thermal fields of South Kamchatka with unload of slightly acidic sulphate waters was studied in this work. Among the salts obtained, the most common phases are those whose mineral analogs are tschermigite, halotrichite, boussingaultite, mascagnite; less widespread are gypsum, koktaite, aluminum-sodium alum and alunogen; even rarer are melanterite, rhomboclase, vanthoffite, coquimbite and bilinite, as well as pickeringite and metavoltine. The hydrolysis of ions of dissolved salts determines the pH value of the pore solutions. Crystalline hydrates of Ca2+, Mg2+, Fe2+, which in nature are represented by such minerals as boussingaultite, koktaite, mascagnite and melanterite, are formed in the pH range = 4.5–7, and vanthoffite, Na6Mg(SO4)4, crystallizes from solutions with pH = 7–8. Hydrated Al sulfates: tschermigite, K- and Na-alum crystallize at pH ~ 4, crystallization of halotrichite, pickeringite and alunogen begins at pH < 3.5. Sulfate solutions containing Fe3+ have a lower pH value than Al sulfate solutions of the same concentration. A concentrated solution of rhomboclase has a pH of ~1, while concentrated solutions of coquimbite and bilinite have a pH of ~3 and below. The paper also presents the calculated values of the pH of pore solutions for mixtures, salts evaporated from it. In the case of several salts, the pH of a solution is determined by its concentration and the relative content of sulfates // Изучен фазовый состав смесей солей, полученных путем выпаривания поровых растворов глин, сформировавшихся на термальных полях гидротермальных систем Южной Камчатки с разгружаю-
щимися на поверхности слабокислыми сульфатными водами. Среди полученных солей наиболее часто встречаются фазы, минеральными аналогами которых являются чермигит, галотрихит, буссенготит, масканьит; менее распространены гипс, коктаит, алюмонатриевые квасцы и алуноген; еще реже встречаются мелантерит, ромбоклаз, вантгоффит, кокимбит и билинит, а также пиккерингит и метавольтин. Гидролиз ионов растворенных солей обусловливает водородный показатель
(pH) поровых растворов. Кристаллогидраты Ca2+, Mg2+, Fe2+, которые в природе представлены такими минералами как буссенготит, коктаит, масканьит и мелантерит, образуются в диапазоне pH = 4.5–7, а вантгоффит, Na6Mg(SO4)4 кристаллизуется из растворов с pH = 7–8. Гидратирован
ные сульфаты Al: чермигит, K- и Na-квасцы кристаллизуются при pH ~ 4, кристаллизация галотрихита, пиккеренгита и алуногена начинается при pH < 3.5. У растворов сульфатов Fe3+ водородный показатель ниже, чем у растворов сульфатов Al3+ той же концентрации. Концентрированный раствор ромбоклаза имеет pH ~ 1, а концентрированные растворы кокимбита и билинита имеют pH ~ 3 и ниже. Приведены расчетные значения водородного показателя поровых растворов для смесей выпаренных из него солей. В случае нескольких солей водородный показатель раствора обусловлен его концентрацией и относительным содержанием сульфатов.
... The last thermal crisis, which started at Vulcano (Aeolian Island, Italy) in 1988 and reached a maximum in 1993, was characterized by an intense deposition of interesting and rare sublimate minerals. With the aim of investigating the correlation between the deposition of the mineralogical phases and the fumarole temperature, composition of the gas phase and the volcanic activity, our team began a systematic mineralogical investigation which led, since 1994, to the discovery of a large variety of rare phases and new minerals (Garavelli, 1994;Garavelli and Vurro, 1994;Ferrara et al., 1995;Coradossi et al., 1996;Borodaev et al., 1998Borodaev et al., , 2000Borodaev et al., , 2001Borodaev et al., , 2003Vurro et al., 1999;Cheynet et al., 2000;Garavelli et al., 1997Garavelli et al., , 2003Garavelli et al., , 2005Garavelli et al., , 2013Garavelli et al., , 2014Pinto et al., 2006aPinto et al., , b, c, 2008Pinto et al., , 2011Pinto et al., , 2014Pinto et al., , 2015aMitolo et al., 2009Mitolo et al., , 2011Mitolo et al., , 2013Balić-Žunić et al., 2016). The abundance and variety of minerals described for the La Fossa crater fumaroles attracted worldwide interest in the mineralogy of the area.Within a few years La Fossa crater became a mineralogical attraction for researchers and collectors. ...
Thermessaite-(NH 4 ), ideally (NH 4 ) 2 AlF 3 (SO 4 ), is a new mineral found as a medium- to high-temperature (~250–300°C) fumarole encrustation at the rim of La Fossa crater, Vulcano, Aeolian Islands, Italy. The mineral deposited as aggregates of minute (<0.2 mm) sharp prismatic crystals on the surface of a pyroclastic breccia in association with thermessaite, sulfur, arcanite, mascagnite, and intermediate members of the arcanite–mascagnite series.
The new mineral is colourless to white, transparent, non-fluorescent, has a vitreous lustre, and a white streak. The calculated density is 2.185 g/cm ³ . Thermessaite-(NH 4 ) is orthorhombic, space group Pbcn , with a = 11.3005(3) Å, b = 8.6125(3) Å, c = 6.8501(2) Å, V = 666.69(4) Å ³ and Z = 4. The eight strongest reflections in the powder X-ray diffraction data [ d in Å ( I )( hkl )] are: 5.65 (100)(200), 4.84 (89)(111), 6.85 (74)(110), 3.06 (56)(112), 3.06 (53)(221), 3.08 (47)(311), 2.68 (28)(022) and 2.78 (26)(130). The average chemical composition, determined by quantitative SEM-EDS (N by difference), is (wt.%): K 2 O 3.38, Al 2 O 3 25.35, SO 3 36.58, F 26.12, (NH 4 ) 2 O 22.47, O = F –11.00, total 102.90. The empirical chemical formula, calculated on the basis of 7 anions per formula unit, is [(NH 4 ) 1.85 K 0.15 ] Σ2.00 Al 1.06 F 2.94 S 0.98 O 3.06 . The crystal structure, determined from single-crystal X-ray diffraction data [ R ( F ) = 0.0367], is characterised by corner-sharing AlF 4 O 2 octahedra which form [001] octahedral chains by sharing two trans fluoride atoms [Al–F2 = 1.8394(6) Å]. Non-bridging Al–F1 distances are shorter [1.756(1) Å]. The two trans oxygen atoms [Al–O = 1.920(2) Å] are from SO 4 tetrahedra. NH 4 ⁺ ions occur in layers parallel to (100) which alternate regularly with (100) layers containing ribbons of corner-sharing AlF 4 O 2 octahedra and associated SO 4 groups. The NH 4 ⁺ ions are surrounded by five oxygen atoms and by four fluorine atoms. The mineral is named as the (NH 4 )-analogue of thermessaite, K 2 AlF 3 (SO 4 ), and corresponds to an anthropogenic phase found in the burning Anna I coal dump of the Anna mine, Aachen, Germany. Both mineral and mineral name have been approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2011-077).
... Что касается легернита, то он был открыт в образце из активной высокотемпературной фумаролы FF кратера Ла Фосса, остров Vulcano, Италия, в виде бесцветных и белых игольчатых кристаллов размером до 0.4 мм, слагающих волокнистые агрегаты, находящиеся в ассоциации с англезитом, баличжуничитом, бисмоклитом, Cd-содержащи м вюртцитом, галенобисмутитом, лиллианитом, пиритом, пирротином и Cd-содержащим сфалеритом (Garavelli et al., 2014). До последнего времени легернит считался эндемиком Vulcano, следовательно, нашу находку этого минерала правомерно считать не только первой на территории Российской Федерации, но и второй в мире. ...
... 4). Подобн ые трудности отмечали и авторы первого описания легернита, которые в силу тонковолокнистого характера минерала получили сумму анализа 90.54 мас.%, сравнимую с нашей (Garavelli et al., 2014). При этом идеальная стехиометрия легернита из Букуки свидетельствует о правильном выборе эталонов и аналитических линий. ...
... Главные линии порошкограмм, d, Å, (I): у каннонита 7.40 (37), 6.90 (10), 6.40 (23), 5.00 (12), 4.15 (28) (7) 748.39 (12) 1 Примечание. 1 -каннонит, Букука; 2 -каннонит, Tunnel Extension, Юта, США (Stanley et al., 1992); 3, 4 -каннонит, Alfenza, Пьем онт, Италия (Capitani et al., 2013); 5 -легернит, Букука; 6 -легернит, фумарола FF, кратер Ла Фосса, о. Vulcano, Италия (Garavelli et al., 2014). ...
Rare bismuth sulfates cannonite Bi2O(SO4)(OH)2 and leguernite Bi12.67O14(SO4)5 have been identified by us as a result of the restudy of the samples of bismuthinite from Bukuka tungsten deposit (Eastern Transbaikalia, Russia), deposited in the systematic collection of the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow under catalogue number 56077. Both minerals are intimately intergrown in polymineral pseudomorphs after bismuthinite forming veins up to 4 cm long and up to 0.5 cm thick. Empirical formulae are as follows: cannonite Bi2.06S0.97O5(OH)2, leguernite Bi12.67S5.00O34. The monoclinic unit-cell dimensions are: cannonite: a = 7.691(1), b = 13.874(2), c = 5.6569(8) Å, β = 109.23(1)°, V = 569.90(9) ų and Z = 4; leguernite: a = 11.197(2), b = 5.714(1), c = 11.879(2) Å, β = 99.37(2)°, V = 749.9(2) ų and Z = 1. Frequencies of strong bands in Raman spectra are for cannonite: 111, 121, 144, 184, 221, 318, 437, 450, 560, 619, 983, 1059, 3439 cm–1, for leguernite: 150, 183, 216, 313, 474, 969 cm–1. Both minerals are found for the first time in Russia.
... Aurivillius (1987) reported formations of Bi 26 O 27 (SO 4 ) 12 and Bi 14 O 16 (SO 4 ) 5 through pyrolysis treatment of the bismuth sulfate Bi 2 (SO 4 ) 3 . The later oxysulfate is significantly similar to the mineral leguernite Bi 12.67 O 14 (SO 4 ) 5 found in high-temperature fumarolic assemblages at La Fossa crater, Vulcano, Aeolian Islands in Italy (Garavelli et al. 2015). Aurivillius (1987) has also reported the crystal structures of the two synthesized oxysulfates. ...
Oxidation roasting of sulfide ores and concentrates, which commonly incorporate considerable amounts of sulfosalts, is useful pre-treatment process in the production of metals, chemicals and energy. In this process, feedstocks are oxidized with air in the temperature range from 873 to 1273 K, and a calcine typically with low-residual sulfur and SO2(g) is produced. As a part of the optimization of this process, in this work, thermal oxidation processes of Ag-Bi-Sb-based sulfides and sulfosalts have been investigated.
Synthesized AgBiS2 and AgSbS2-Sb2S3-Sb samples were thermally analyzed in an oxidizing atmosphere by applying the simultaneous DSC-TGA analysis technique. The DSC-TGA versus temperature measurements in air revealed that AgBiS2 and AgSbS2 undergo polymorphic phase transitions at 457.9 ± 2 K and 648.9 ± 2 K, respectively. The thermal oxidation processes at PO₂ = 0.2 atm and below 1173 K have been observed to take place in many-step sequence of various chemical reactions that involve formations and decompositions of sulfates with an overall reaction 2AgMeS2 + 5.5O2(g) ⇄ 2Ag + Me2O3 + 4SO2(g), where Me = (Bi, Sb). Oxidations of AgBiS2, Sb2S3, and AgSbS2 were observed to begin above 549 ± 2 K, 610 ± 2 K, and 733 ± 2 K, respectively. The cooled samples after each run was composed of Ag and Me2O3. Based on the results obtained for the AgMeS2 phases, the high-temperature oxidation processes of AgBi3S5 and Ag3SbS3 were estimated. Thermodynamic functions for the overall oxidation reactions were calculated and discussed.
https://doi.org/10.1080/08827508.2018.1481061
... Linarite, Ve [9]: rare microscopic crystals in gypsum. Balićžunićite [13] and leguern‐ ite [91]: in cavities of a sample taken from the high-temperature fumarole (T = 600°C) in minute transparent prismatic crystals in association with anglesite and in the vicinity of sulphosalt formation. Very rare. ...
The fumarolic mineralogy of the Icelandic active volcanoes, the Tyrrhenian volcanic belt (Italy) and the Aegean active arc (Greece) is investigated, and literature data surveyed in order to define the characteristics of the European fumarolic systems. They show broad diversity of mineral associations, with Vesuvius and Vulcano being also among the world localities richest in mineral species. Volcanic systems, which show recession over a longer period, show fumarolic development from the high-temperature alkaline halide/sulphate, calcic sulphate or sulphidic parageneses, synchronous with or immediately following the eruptions, through medium-temperature ammonium minerals, metal chlorides, or fluoride associations to the late low-temperature paragenesis dominated by sulphur, gypsum, alunogen, and other hydrous sulphates. The situation can be different in the systems that are not recessing but show fluctuations in activity, illustrated by the example of Vulcano where the high-temperature association appears intermittently. A full survey of the mineral groups and species is given in respect to their importance and appearance in fumarolic associations.
... Due to their environmental and planetary importance, sulfate minerals continue to attract the attention of mineralogists, geochemists and crystallographers (Hammarstrom et al., 2005;Bibring et al., 2007). During the past few years, some of the major 'suppliers' of novel sulfate mineral species have been volcanic fumaroles such as La Fossa crater at Volcano (Aeolian islands, Italy) (Demartin et al., 2008(Demartin et al., , 2010(Demartin et al., , 2012(Demartin et al., , 2015Mitolo et al., 2013;Garavelli et al., 2014;Pinto et al., 2014Pinto et al., , 2015 and Tolbachik volcano (Kamchatka peninsula, Russia) (Pekov et al., 2012(Pekov et al., , 2014(Pekov et al., , 2016Siidra et al., 2014a, b and c). The latter was active in 1975-76 and experienced another stage of eruptive activity in 2012-2013 (Karpov et al., 2013;Filatov et al., 2014). ...
Bubnovaite, ideally K2Na8Ca(SO4)(6), has been found in volcanic fumaroles of the 2012-2013 Tolbachik fissure eruption, Kamchatka peninsula, on the new cinder Naboko cone. Bubnovaite occurs as aggregates of light-blue needle-like or tabular crystals associated with aphthitalite and thenardite. The calculated density is 2.655 g/cm(3). The mineral is uniaxial, optically negative, omega = 1.492(2), epsilon = 1.489(2). No pleochroism has been observed. Bubnovaite is trigonal, space group P31c, a= 10.804(3), c = 22.011(6) angstrom, V = 2225(2) angstrom(3), Z = 4 (from single-crystal diffraction data). The eight strongest lines of the X-ray powder diffraction pattern are (I d(angstrom)-hkl): 80-3.943-023, 35-2.894-026, 62-2.868-033, 91-2.718-034, 100-2.707-220, 10-2.647-018, 6-2.231-135, 21-1.970-046. The chemical composition determined by electron-microprobe analysis is (wt.%): Na2O 26.99, K2O 10.99, CaO 4.27, MgO 0.51, CuO 1.21, ZnO 0.81, PbO 1.58, SO3 54.93, total 101.30. The empirical formula based on 24 0 atoms is Na7.65K2.05 (Ca0.67Mg0.11Cu0.13Zn0.09Pb0.06)Sigma 1.06S6.03O0.24. The simplified formula is K2Na8Ca(SO4)(6), which requires Na2O 28.22, K2O 10.72, CaO 6.38, SO3 54.68, total 100 wt.%. The crystal structure of bubnovaite (R-1 = 0.078) can be described as based upon an ABACABACABAC twelve-layer superstructure of K, Na and Ca cations with partially disordered SO4 tetrahedra. Bubnovaite is closely related to alpha-K2SO4; 'metathenardite', Na2SO4; aphthitalite, K3Na(SO4)(2); and hanksite, Na22K(SO4)(9)(CO3)(2)Cl. The mineral is named in honour of Professor Rimma Sergeevna Bubnova, Institute of Silicate Chemistry, Russian Academy of Sciences, Saint Petersburg State University, St. Petersburg, Russia, for her important contributions to the crystal chemistry of vanadates, silicates, borates, borosilicates and other inorganic oxysalts.
... The following analytical conditions were with rounding errors. The slight overestimation of sulfur, as well as the underestimation of Bi, has also been reported for leguernite by Garavelli et al. (2014) and related both to the small thickness of the analysed sample and to the behaviour of sulfates with respect to the standard under the electron beam. The simplified chemical formula is Bi 4 O 4 (SO 4 )(OH) 2 , which requires Bi 2 O 3 90.48, ...
The new mineral species tavagnascoite, Bi4O4(SO4)(OH)2, has been discovered in the Pb-Bi-Zn-As- Fe-Cu ore district from Tavagnasco, Turin, Piedmont, Italy. It occurs as blocky colourless crystals, up to 40 micron in size, with a silky lustre. In the studied specimen, tavagnascoite is associated with other uncharacterized secondary Bi-minerals originating from the alteration of a bismuthinite ± Bi sulfosalts assemblage. Electron microprobe analysis gave (average of 3 spot analyses – in wt%): Bi2O3 85.32, Sb2O3 0.58, PbO 2.18, SO3 8.46, H2Ocalc 1.77, sum 98.31. On the basis of 10 O atoms per formula unit, the chemical formula is (Bi3.74Pb0.10Sb0.04)somma=3.88O3.68(SO4)1.08(OH)2, with rounding errors. Main calculated diffraction lines are [d in Å (relative intensity) hkl]: 6.39 (29) 012, 4.95 (19) 111, 4.019 (32) 121, 3.604 (28) 014, and 3.213 (100) 123. Unit-cell parameters are a = 5.831(1), b = 11.925(2), c = 15.123(1) Å, V = 1051.6(3) Å3, Z = 4, space group Pca21. The crystal structure has been solved and refined from single-crystal X-ray diffraction data to R1 = 0.037 on the basis of 1269 observed reflections. It consists of Bi–O polyhedra and SO4 tetrahedra. Bismuth polyhedra are connected each to other to form Bi–O sheets parallel to (001). Successive sheets are linked together by SO4 groups and hydrogen bonds. Tavagnascoite is the Bi-analogue of klebelsbergite, Sb4O4(SO4)(OH)2, and it is the fifth natural known bismuth sulfate without additional cations. The mineral and its name have been approved by the IMA CNMNC (2014-099).
... The coordination environment of these atoms is completed by additional weakly bonded O atoms at distances from $ 2.50 to 3.29 Å , giving rise to very irregular total coordination geometries, varying from fourfold to eightfold. Such asymmetrical coordination is very common in Bi 3+ compounds and indicate the presence of stereochemically active 6sp 2 lone-pair electrons (Aurivillius et al., 1988;Garavelli et al., 2014;Pinto et al., 2015). When considering only the closest O atoms, the coordinations of Bi 3+ atoms ( Fig. 2) in both the structures fall into two categories: distorted tetrahedral BiO 3 E (Bi2, Bi3, Bi4, Bi5 and Bi7 in the structure of new phase I and Bi1, Bi5, Bi7, Bi8, Bi13, Bi14, Bi17 to Bi22, Bi27 to Bi30 in the structure of new phase II) and distorted trigonal bipyramidal BiO 4 E (Bi1 and Bi6 in the structure of new phase I and Bi2, Bi3, Bi4, Bi6, Bi9, Bi10, Bi11, Bi12, Bi15, Bi16, Bi23, Bi24, Bi25, Bi26 in the structure of new phase II), where E denotes stereochemically active lone-pair electrons which is assumed to occupy the vacant space in the coordination environment (Andersson et al., 1973;Galy et al., 1975). ...
... Columns of OBi 4 edge-sharing tetrahedra with a 3 Â 2 cross section in the crystal structure of leguernite projected along [010]. FromGaravelli et al. (2014). ...
The crystal structures of two new natural Bi oxysulfates with the formula Bi14O16(SO4)5 [labelled new phase I; monoclinic, space group C2, a = 21.658 (4), b = 5.6648 (9), c = 15.092 (3) Å, β = 119.433 (11)° and Z = 2] and Bi30O33(SO4)9(AsO4)2 [labelled new phase II; triclinic, space group P1, a = 5.670 (3), b = 13.9408 (9), c = 22.7908 (18) Å, α = 80.903 (5), β = 82.854 (14), γ = 78.27 (2)° and Z = 1] from the high-temperature fumarole deposit of the La Fossa crater at Vulcano (Aeolian Islands, Italy) are reported. The structures are built up by a combination of fluorite-related Bi—O units and isolated (SO4)2− tetrahedra (new phase I) or both (SO4)2− and (AsO4)3− tetrahedra (new phase II). Owing to the effect of stereoactive lone pairs of Bi3+, Bi—O units in both the structures can be suitably described in terms of oxo-centered OBi4 tetrahedra. The structure of Bi14O16(SO4)5 is based upon one-dimensional [O16Bi14]10+ ribbons formed by six chains of edge-sharing OBi4 tetrahedra extending along [010]. In the structure of Bi30O33(SO4)9(AsO4)2 the same ribbon type coexists with another one-dimensional ribbon formed by seven chains of edge-sharing OBi4 tetrahedra and with the composition [O17Bi16]14+. Ribbons of the same type are joined by (SO4)2− and (AsO4)3− tetrahedra along [010] – if a reduced triclinic unit-cell setting is considered – so forming two different (001) slabs which alternate to each other along [001] and are joined by additional (SO4)2− tetrahedra. New phase I represents the natural analogues of synthetic Bi14O16(SO4)5, but with an ordered structure model.
... From the side of the three more distant oxygens, Bi is approached by two more oxygens at 2.77 and 3.02 A ˚ (Fig. 4d). Taking into account the general assumptions of the valence-shell electron-pair repulsion (VSEPR) model (Gillespie and Nyholm, 1957;Gillespie, 1963aGillespie, ,b, 2008and references therein) and its extension by Andersson, Galy and coworkers (Andersson et al., 1973;Galy et al., 1975Bi atoms in the crystal structures of leguernite (Garavelli et al., 2014, 1987). The Bi atoms with trigonal bipyramidal BiO 4 E coordinations are Bi(3) and Bi(4). ...
... They show two oxygen atoms in the axial positions and three equatorial positions occupied by two oxygens and a sterically active lone electron pair, respectively. It represents one of the most common oxygen coordinations of lone pair elements (Gillespie, 1963b) and occurs in several Bi and Sb minerals and synthetic compounds such as a-Bi 2 O 3 (Malmros, 1970), b-Bi 2 O 3 (Blower and Greaves, 1988), Bi 14 O 20 (SO 4 ) (Francesconi et al., 1998), leguernite, Bi 12.67 O 14 (SO 4 ) 5 (Garavelli et al., 2014), cannonite, Bi 2 (SO 4 )O(OH) 2 (Capitani et al., 2013), Sb 4 O 2 (OH)(SO 4 ) 4 (H 5 O 2 )H 2 O (Douglade and Mercer, 1980), SbPO 4 (Kinberger, 1970) and synthetic monoclinic Bi 2 O(SO 4 ) 2 (Aurivillius, 1988). The BiÀO equatorial bonds in Bi(3) and Bi(4) coordinations of balic´žunic´itebalic´žunicbalic´žunic´ite are ~2.1 ...
... Aurivillius (1988) pointed out that owing to the large average MÀO distances, the influence of the lone pair in Bi-oxide compounds may be less than it is for Sb in Sb-oxide compounds, so less rigid trigonal bipyramids can be expected in the former with respect to the latter. Taking into account this consideration we may suppose that the angles of ~72º observed in BiO 4 E coordinations of the balic´žunic´itebalic´žunicbalic´žunic´ite structure and its high-temperature polymorph (Aurivillius, 1988) are not only due to electron repulsion effects associated with lone-pair electrons , but also by packing effects connected to the presence of strongly bonded groupsBiGaravelli et al., 2014)] are characterized by fluorite-like structural portions in which oxo oxygens occupy larger tetrahedral holes. The Bi atoms in the balic´žunic´itebalic´žunicbalic´žunic´ite structure showing distorted square bipyramidal BiO 5 E coordination are Bi(1), Bi(2) and Bi(5). ...
The crystal structure of balićžunićite, Bi2O(SO4)2, a new mineral species from the La Fossa crater of Vulcano (Aeolian Islands, Italy), was solved from single-crystal X-ray diffraction data and refined to R = 0.0507. The structure is triclinic, space group P1, with a = 6.7386(3), b = 11.1844(5), c = 14.1754(7) Å, α = 80.082(2), β = 88.462(2)°, γ = 89.517(2)°, V = 1052.01(8) Å3 and Z = 6. The crystal structure consists of six independent Bi sites, six S sites and 27 O sites of which three are oxo oxygen atoms not bonded to sulfur. Bismuth and S atoms are arranged close to a eutectic pattern parallel to the (100) plane. The planes are stacked atom on atom such that Bi always overlays S and vice versa. This structural feature is shared with the known structure of the high-temperature polymorph of the same compound, stable at T >535°C. However, the sequences of Bi and S atoms in the two structures are different and so are the arrangements of oxygen atoms. Characteristic building blocks in the structure of balićžunićite are clusters of five Bi atoms which form nearly planar trapezoidal Bi5 groups with oxo oxygens located in the centres of the three Bi3 triangles, which form the trapezoids. The trapezoidal Bi5O39+ ions are joined along [100] with SO42– groups by means of strong bismuth-sulfate oxygen bonds, forming infinite [100] rods with composition Bi5O3(SO4)5–. One sixth of the Bi atoms do not participate in trapezoids, but form, with additional SO42– groups, rows of composition BiSO4+, also parallel to [100]. [Bi5O3(SO4)5–] rods form infinite layers parallel to (010) with [BiSO4+] rows located on the irregular surface of contact between adjacent layers. Bi atoms occur in four different coordination types, all showing the stereochemical influence of the Bi3+lone electron pair. In this respect the crystal structure of balićžunićite shows greater variability than its high-temperature polymorph which has only two types of the Bi coordination spheres present in balićžunićite.
... In 1987 (Tmax & 330ºC) sulfur, salammoniac and sassolite were the only minerals deposited in the fumaroles of La Fossa crater, whereas from 1990 onwards the mineralogy of the crater fumaroles began to be dominated by sulfides and sulfosalts (Garavelli et al.,1997). These are (IMA2013-51, Garavelli et al., 2013b;Garavelli et al., 2014) and a third potentially new Bi-oxysulfate with probable composition Bi 14 O 16 (SO 4 ) 5, which is still under investigation. These phases have been found in small cavities on sample rocks on which reduced phases like lillianite and galenobismutite are the main sublimate minerals deposited on the surface, thus indicating the simultaneous existence of small areas of oxidizing conditions near to reducing environments. ...
... The sample was collected at Vulcano in 1990 from the hightemperature fumarole FF (T = 600ºC, direct measurement), which was sited on the inner slope of the crater (Fig. 1). Balićžunićite forms transparent and minute, elongated, prismatic crystals associated closely with anglesite PbSO 4 , the new Bi-sulfate leguernite, Bi 12.67 O 14 (SO 4 ) 5 Garavelli et al., 2014) and one other unknown Bi-sulfate still under investigation. Additional minerals present on the same hand specimen from which balićžunićite was identified, but not associated closely with it, are: lillianite, galenobismutite, bismoclite, Cdrich sphalerite, wurtzite, pyrite and pyrrhotite. ...
... Balićžunicite is a new Bi sulfate which was discovered in one small cavity on the surface of a rock sample collected from the walls of a hightemperature (T = 600ºC) fumarole from La Fossa crater at Vulcano. In the small area where balićžunicite was deposited, this new mineral was found associated closely with anglesite Pb(SO) 4 , one other Bi oxysulfate approved recently as a new mineral, leguernite, Bi 12.67 O 14 (SO 4 ) 5 Garavelli et al., 2014) and a third unknown Bioxysulfate still under investigation. On the surface of the same hand specimen from which balićžunićite was identified, other minerals such as sulfides and sulfosalts like lillianite, galenobismutite, Cd-rich sphalerite, wurtzite, pyrite and pyrrhotite are present, but not in close association with the new mineral. ...
Balićžunićite, ideally Bi 2 O(SO 4 ) 2 , is a new mineral found as a high-temperature fumarole sublimate ( T = 600°C) at La Fossa crater, Vulcano, Aeolian Islands, Italy. It occurs as aggregates of mm-sized prismatic and elongated crystals (∼50 μm across and up to 200 μm long) associated with anglesite, leguernite, one other potentially new Bi-oxysulfate mineral, lillianite, galenobismutite, bismoclite, Cd-rich sphalerite, wurtzite, pyrite and pyrrhotite. Balićžunićite is colourless to white or pale brown, transparent and non-fluorescent. It has a vitreous lustre and a white streak. Electron microprobe analysis gives the following average chemical composition (wt.%): Bi 2 O 3 68.68 and SO 3 23.73, total 92.41. The empirical chemical formula, calculated on the basis of 9 anions p.f.u., is Bi 1.99 S 2 O 9 . The calculated density is 5.911 g/cm ³ .
Balićžunićite is triclinic, space group P , with a 6.7386(3), b 11.1844(5), c 14.1754(7) Å, α 80.082(2)°, β 88.462(2)°, γ 89.517(2)°, V = 1052.01(8) Å ³ and Z = 6. The six strongest reflections in the X-ray powder-diffraction data [ d in Å( I ) ( hkl )] are: 3.146 (100) (033), 3.486 (21) (004), 3.409 (12) (0 1), 3.366 (7) (200), 5.562 (4) ( 11), 5.433 (4) (111). Balićžunićite is the natural analogue of the stable low-temperature a form of synthetic Bi 2 O(SO 4 ) 2 . The name is in honour of Tonci Balić-Žunić(born 1952), Professor of Mineralogy at the Natural History Museum of the University of Cophenagen. Both the mineral and the mineral name have been approved by the IMA-CNMNC Commission (IMA2012-098).
