Thermessaite-(NH4), (NH4)2AlF3(SO4), a new fumarole mineral from La Fossa crater at Vulcano, Aeolian Islands, Italy

AbstractLeguernite, 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 needleshaped crystals associated strictly with anglesite, balićžunićite and an unknown Bi sulfate. Leguernite is colourless to white, transparent, non-fluorescent, has a sub-adamantine lustre and a white streak. Electron microprobe data led to the chemical formula (on the basis of 34 anions p.f.u.) (Bi12.40Pb0.15)Σ=12.55S5.08O34. The calculated density is 7.375 g cm–3. A Raman spectrum collected on a single crystal of leguernite confirmed the anhydrous nature of the mineral.Leguernite is monoclinic, space group P2, with a = 11.2486(11), b = 5.6568(6), c = 11.9139(10) Å , β = 99.177(7)º, V = 748.39(12) Å3 and Z = 1. The crystal structure is built up of Bi–O blocks of a fluorite-like structure with Bi12O14 composition separated by a single sulfate ion along [100] and by Bi(SO4)45– groups along [101]. It can also be described as composed of (001) layers with composition [Bi12O14(SO4)6+]n alternating with layers of composition [Bi(SO4)4]n5– along [001]. Leguernite shows significant similarities with the synthetic Bi14O16(SO4)5 compound.The eight strongest reflections in the powder X-ray diffraction data [d in Å (I) (hkl)] are: 3.220 (100) (013), 3.100 (95) (11), 2.83 (30) (020), 2.931 (25) (302), 2.502 (25) (04), 2.035 (20) (322), 1.875 (20) (24) and 5.040 (15) (110).The name is in honour of Franc¸ois “Fanfan” Le Guern (1942–2011), who was a very active volcanologist and specialist in volcanic gases and sublimates. Both the mineral and the mineral name have been approved by the IMA-CNMNC (2013–051).

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Acmonidesite, a new ammonium sulfate chloride from La Fossa crater, Vulcano, Aeolian Islands, Italy

Mineralogical Magazine ◽

10.1180/mgm.2018.115 ◽

2018 ◽

Vol 83 (1) ◽

pp. 137-142 ◽

Cited By ~ 1

Author(s):

Francesco Demartin ◽

Carlo Castellano ◽

Italo Campostrini

Keyword(s):

Three Dimensional ◽

Dimensional Structure ◽

New Mineral ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

Chlorine Atoms ◽

Calculated Density ◽

Sulfate Ions ◽

Aeolian Islands ◽

Fossa Crater

AbstractThe new mineral acmonidesite, (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8, was found in an active fumarole (fumarole FA, temperature ~250°C) at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as brown prismatic crystals up to 0.10 mm long, in association with salammoniac, alunite and adranosite. The mineral is orthorhombic, space group C2221 (no. 20) with a = 9.841(1), b = 19.448(3) c = 17.847(3) Å, V = 3415.7(9) Å3 and Z = 4. The six strongest reflections in the powder X-ray diffraction pattern are: [dobs in Å(I)(hkl)] 8.766(100)(110), 1.805(88)(390), 5.178(45)(131), 4.250(42)(221), 2.926(42)(330) and 2.684(32)(261). The empirical formula (based on 28 anions per formula unit [pfu]) is (NH4)5.77K1.42Pb0.62Na1.24Fe3.96Mn0.08S5.04O20.16Cl7.97Br0.08. The idealised formula is (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8. The calculated density is 2.551 g cm–3. Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0363 for 4614 independent observed reflections [I > 2σ(I)]. The structure contains two independent, distorted octahedral iron sites, Fe1 and Fe2, with the iron atoms in the 2+ oxidation state, as confirmed by the interatomic distances and bond-valence calculations (2.06 and 1.94 vu, respectively). Fe1 is surrounded by two chlorine atoms and four oxygens of the sulfate ions, with the following average distances (Å): Fe1–O 2.125 and Fe1–Cl 2.472; and Fe2 is surrounded by three chlorine atoms and three oxygens of the sulfate ions, with the following average distances (Å): Fe2–O 2.110 and Fe2–Cl 2.531. Three independent sulfate anions are also present and are connected with the iron polyhedra to form a three-dimensional structure containing voids occupied by four independent ammonium ions (two of them partially replaced by K+), one Na+/Pb2+ site and one Cl– ion.

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Balićžunićite, Bi2O(SO4)2, a new fumarole mineral from La Fossa crater, Vulcano, Aeolian Islands, Italy

Mineralogical Magazine ◽

10.1180/minmag.2014.078.4.15 ◽

2014 ◽

Vol 78 (4) ◽

pp. 1043-1055 ◽

Cited By ~ 9

Author(s):

D. Pinto ◽

A. Garavelli ◽

D. Mitolo

Keyword(s):

New Mineral ◽

Average Chemical Composition ◽

Calculated Density ◽

Triclinic Space Group ◽

Aeolian Islands ◽

History Museum ◽

X Ray ◽

The University ◽

Fossa Crater ◽

Fumarole Sublimate

AbstractBalićžunićite, ideally Bi2O(SO4)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.%): Bi2O3 68.68 and SO3 23.73, total 92.41. The empirical chemical formula, calculated on the basis of 9 anions p.f.u., is Bi1.99S2O9. The calculated density is 5.911 g/cm3.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) Å3 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) (01), 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 Bi2O(SO4)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).

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Aiolosite, Na2(Na2Bi)(SO4)3Cl, a new sulfate isotypic to apatite from La Fossa Crater, Vulcano, Aeolian Islands, Italy

American Mineralogist ◽

10.2138/am.2010.3337 ◽

2010 ◽

Vol 95 (2-3) ◽

pp. 382-385 ◽

Cited By ~ 10

Author(s):

F. Demartin ◽

C. M. Gramaccioli ◽

I. Campostrini ◽

T. Pilati

Keyword(s):

Aeolian Islands ◽

Fossa Crater

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Campostriniite, (Bi3+,Na)3(NH4,K)2Na2(SO4)6·H2O, a new sulfate isostructural with görgeyite, from La Fossa Crater, Vulcano, Aeolian Islands, Italy

Mineralogical Magazine ◽

10.1180/minmag.2015.079.4.10 ◽

2015 ◽

Vol 79 (4) ◽

pp. 1007-1018 ◽

Cited By ~ 2

Author(s):

Francesco Demartin ◽

Carlo Castellano ◽

Carlo Maria Gramaccioli

Keyword(s):

General Position ◽

New Mineral ◽

Monoclinic Space Group ◽

Fold Axis ◽

X Ray Diffraction ◽

Single Crystal Diffraction ◽

Calculated Density ◽

Aeolian Islands ◽

Na Ions ◽

Fossa Crater

AbstractThe new mineral campostriniite, (Bi3+,Na)3(NH4,K)2Na2(SO4)6·H2O, was found in an active fumarole (fumarole FA, temperature ∼350°C) at La Fossa Crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as white prismatic crystals up to 0.2 mm long, in association with adranosite, demicheleite-(Br), demicheleite-(I), argesite and sassolite. The mineral is monoclinic, space group: C2/c (no. 15) with a = 17.748(3), b = 6.982(1) c = 18.221(3) Å, β = 113.97(1)°, V = 2063(1) Å3 and Z = 4. The six strongest reflections in the powder X-ray diffraction pattern are: [dobs in Å (I)(hkl)] 6.396(100)(110), 7.507(75)(202), 2.766(60)(316), 3.380(57)(312), 5.677(55)(111), 3.166(50)(4 0 2). The empirical formula (based on 25 anions p.f.u.) is Bi2.41N1.52Na2.41K0.48 S6.07H8.08O25. The calculated density is 3.87 g cm–3. Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.051 for 3025 independent observed reflections [I > 2σ(I)]. Campostriniite is isostructural with görgeyite and belongs to the 7.CD group of the Strunz classification system. The structure contains two independent nine-fold coordinated sites, one of them located on a two-fold axis (M1) and the other one in general position (M2) essentially occupied by Bi3+ atoms and minor amounts of Na+ ions, an eight-fold coordinated site fully occupied by Na +ions and another eight-fold coordinated site occupied by NH+4 and K+ ions; three independent sulfate anions in a general position and a water molecule coordinated to M1 and located on a two-fold axis are also present.

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