AustriaAbstractThe new mineral adranosite-(Fe), ideally (NH4)4NaFe2(SO4)4Cl(OH)2, is the Fe3+-analogue of adranosite. It was found on a pyroclastic breccia in two different fumaroles at “La Fossa” crater of Vulcano, Aeolian Islands, Italy, and corresponds to an anthropogenic product previously observed in a burning coal dump at the Anna mine, near Aachen, Germany. The mineral is tetragonal, space group I41/acd (no. 142), with a = 18.261(2), c = 11.562(1) Å, V = 3855.5(7) Å3 (single-crystal data), and Z = 8. The six strongest reflections in the X-ray powder diffraction pattern are [dobs in Å(I)(hkl)]: 9.134(100)(020), 4.569(83)(040), 3.047(79)(152), 6.462(36)(220), 3.232(29)(251), and 2.891(11)(004). The average chemical composition of the holotype is (wt.%): Na2O 5.01, Fe2O3 15.77, Al2O3 5.11, K2O 0.82, (NH4)2O 15.76, SO3 50.96, Cl 3.71, H2O 2.75, –O≡Cl –0.84, total 99.05; the corresponding empirical formula is: [(NH4)3.89K0.11]Σ4.00Na1.04[Fe1.27Al0.64]Σ1.91S4.10O16.40Cl0.67(OH)1.96. Adranosite-(Fe) forms aggregates of pale yellow acicular crystals up to 1 mm in length, the most common forms most probably being {100}, {110}, and {111}. The measured density is 2.18(1) g/cm3, and the calculated density is 2.195 g/cm3. Adranosite-(Fe) is uniaxial (–) with ω = 1.58(1), ε = 1.57(1) (l = 589 nm). Using single-crystal X-ray diffraction data from the holotype, the structure was refined to a final R(F) = 0.0415 for 670 independent observed reflections [I > 2σ(I)]. Adranosite-(Fe) is isostructural with its Al-analogue adranosite and contains NaO4Cl2 square tetragonal bipyramids, linked through their opposite Cl corners and helicoidal chains with composition [FeO4(OH)2SO4]n, both extending along [001]. The framework resulting from the sharing of the sulfate ions between the different chains displays cages in which the nine-coordinated hydrogen-bonded NH4+ ions are hosted.

Balic´zˇunic´ite, ideally Bi2O(SO4)2, is a new mineral found as a high-temperature fumarole sublimate (T = 600ºC) at La Fossa crater, Vulcano, Aeolian Islands, Italy. It occurs as aggregates of mm-sized prismatic and elongated crystals (~50 mm across and up to 200 mm long) associated with anglesite, leguernite, one other potentially new Bi-oxysulfate mineral, lillianite, galenobismutite, bismoclite, Cd-rich sphalerite, wurtzite, pyrite and pyrrhotite. Balic´zˇunic´ite is colourless to white or pale brown, transparent, non-fluorescent. It has a vitreous lustre and a white streak. Electron microprobe analyses 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. Balic´zˇunic´ite is triclinic, space group P1¯ , with a 6.7386(3), b 11.1844(5), c 14.1754(7) A ˚ , a 80.082(2)º, b 88.462(2)º, g 89.517(2)º, V = 1052.01(8) A ˚ 3 and Z = 6. The six strongest reflections in the X-ray powder-diffraction data [d in A ˚ (I) (hkl)] are: 3.146 (100) (033), 3.486 (21) (004), 3.409 (12) (03¯ 1), 3.366 (7) (200), 5.562 (4) (111), 5.433 (4) (1¯11). Balic´zˇunic´ite is the natural analogue of the stable low-temperature a form of synthetic Bi2O(SO4)2. The name is in honour of Tonci Balic´-Zˇ unic´ (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).

The new mineral jakobssonite, ideally CaAlF5, was first found in crusts collected in 1988 from a fumarole on the Eldfell volcano, Heimaey Island, Iceland. It was subsequently found in similar crusts collected in 1991 from a fumarole on the Hekla volcano, Iceland. It is associated with leonardsenite (IMA2011-059), ralstonite, heklaite, anhydrite, gypsum, jarosite, hematite, opal and several fluoride minerals that have not been fully characterized. Jakobssonite occurs as soft white fragile crusts of acicular crystals <50 mm long. Its calculated density is 2.89 g cm-3. Chemical analyses by energy-dispersive spectrometry on a scanning electron microscope produced a mean elemental composition as follows: Ca, 18.99; Al, 18.55; Mg, 1.33; Na, 0.33; F, 50.20; O, 10.39; total 99.79 wt.%. The empirical chemical formula, calculated on the basis of 7 atoms per formula unit with all of the oxygen as OH, is (Ca0.73Mg0.09Na0.02)S0.84Al1.06F4.09(OH)1.01. Jakobssonite is monoclinic, space group C2/c, with a = 8.601(1), b = 6.2903(6), c = 7.2190(7) A ˚ , b = 114.61(1)o, V = 355.09(8) A ˚3 and Z = 4. The crystal structure contains chains of [AlF6] octahedra which run parallel to the c axis. These chains are interconnected by chains of [CaF7] pentagonal bipyramids. Jakobssonite is isostructural with several other CaMIIIF5 compounds. The eight strongest lines in the powder diffraction diagram [d in A ˚ (I) (hkl)] are as follows: 4.91 (18) (110), 3.92 (76) (200), 3.15 (68) (020), 3.13 (100) (11¯2¯ ), 2.27 (22) (22¯2¯ ), 1.957 (21) (400), 1.814 (20) (13¯2¯ ), 1.805 (22) (204¯ ). The chemical and crystal-structure analyses of jakobssonite are similar to synthetic CaAlF5 with minor substitutions of light elements (e.g. Na) or vacancies for Ca, and OH for F.

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, 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)°, 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 Formula groups along [101]. It can also be described as composed of (001) layers with composition [Bi12O14(SO4)6+]n alternating with layers of composition Formula 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) (3İ11), 2.83 (30) (020), 2.931 (25) (302), 2.502 (25) (3İ04), 2.035 (20) (322), 1.875 (20) (3İ24) and 5.040 (15) (110). The name is in honour of François “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).

Leonardsenite (IMA2011-059), with ideal formula MgAlF5(H2O)2, is a new fumarole mineral from Eldfell volcano, Iceland. It has also been found in volcanic encrustations from the Hekla crater, Iceland. The mineral forms a soft and friable mass of white crystals up to 20 μm in length. The streak is white and the luster is earthy. The calculated density is 2.31 g cm–3. Leonardsenite is orthorhombic, space group Imma; the lattice parameters, obtained from Rietveld refinement of the XRPD data, are: a 7.055(1) Å, b 10.117(2) Å, c 6.813(1) Å, V 486.3(1) Å3, and Z = 4. The eight strongest reflections in the X-ray powder diffraction pattern are [d in Å (I) (hkl)]: 5.66 (100) (011), 4.92 (29) (101), 3.53 (27) (200), 3.03 (31) (031), 3.00 (38) (211), 2.30 (16) (231), 1.77 (19) (400), 1.76 (24) (242). Chemical analyses by energy-dispersive spectrometry using a scanning electron microscope produced a mean elemental composition as follows (wt.%): Mg 14.66, Al 16.16, F 52.98, O 15.88, H 1.78, total 101.46. The corresponding empirical formula, calculated on the basis of 2 cations pfu, is Mg1.00Al1.00[F4.64(OH)0.36]Σ5.00(H2O)1.29. On the basis of chemical analyses and X-ray diffraction data, leonardsenite corresponds to the synthetic compound MgAlF5(H2O)2. The crystal structure of leonardsenite contains infinite chains of [AlF6] octahedra along the c-axis which are connected via common fluorine atoms to isolated [MgF4(H2O)2] octahedra. Leonardsenite is the first aluminum fluoride hydrated mineral of the inverse weberite group with general formula MIIMIIIF5(H2O)2. Leonardsenite belongs to the group of fluorides with interesting optical and catalytic properties. The name of this new species honors Erik Leonardsen (1934–), the former leader of the X-Ray Diffraction Laboratory of the Geological Institute, University of Copenhagen. The mineral and its name have been approved by the IMA-CNMNC (IMA2011-059).

Lucabindiite, ideally (K,NH4)As4O6(Cl,Br), is a new mineral found as a medium-temperature fumarole encrustation (T = 170 °C) at “La Fossa” crater of Vulcano, Aeolian Islands, Italy. The mineral deposited as aggregates of micrometer-sized hexagonal and platy crystals on the surface of the pyroclastic breccia in association with arsenolite, sal ammoniac, sulfur, and amorphous arsenic-rich sulfurite. The new mineral is colorless to white, transparent, non-fluorescent, has a vitreous luster and a white streak. The calculated density is 3.68 g/cm3. Lucabindiite is hexagonal, space group P6/mmm, with a = 5.2386(7) Å, c = 9.014(2) Å, V = 214.23(7) Å3, and Z = 1. The eight strongest reflections in the X-ray powder-diffraction data [d in Å (I) (hkl)] are: 3.20 (100) (102), 2.62 (67) (110), 4.51 (52) (002), 4.54 (30) (100), 1.97 (28) (113), 1.49 (21) (115), 1.60 (21) (212), 2.26 (19) (112). Lucabindiite’s average chemical composition is (wt%): K2O 5.14, As2O3 84.71, Cl 3.63, Br 6.92, F 0.77, (NH4)2O 2.73, O=F,Cl,Br –1.84, total 102.06. The empirical chemical formula, calculated on the basis of 7 anions pfu, is [K0.51(NH4)0.49]Σ1.00 As4.00O5.93(Cl0.48Br0.40F0.19)Σ1.07. According to chemical analyses and X-ray data, lucabindiite is the natural analog of synthetic phases with general formula MAs4O6X where M = K, NH4 and × = Cl, Br, I. The crystal structure is characterized by neutral As2O3 sheets arranged parallel to (001). The As atoms of two neighboring sheets point at each other and the sheets are separated by interlayer M (=K, NH4) and × (=Cl, Br, F) atoms. The name is in honor of Luca Bindi (b. 1971), Professor of Mineralogy and former Head of the Division of Mineralogy of the Natural History Museum of the University of Florence. Both the mineral and the mineral name have been approved by the IMA-CNMNC Commission (IMA 2011-010).

The new mineral oskarssonite (IMA2012-088), with ideal formula AlF3, was found in August 2009 at the surface of fumaroles on the Eldfell volcano, Heimaey Island, Iceland (GPS coordinates 63º25’58.9’’N 20º14’50.3’’W). It occurs as sub-micron-sized crystals forming a white powder in association with anhydrite, bassanite, gypsum, jarosite, anatase, hematite, opal, ralstonite, jakobssonite and meniaylovite. Chemical analyses by energy-dispersive spectrometry with a scanning electronmicroscope produced the following mean elemental composition: Al, 31.70; F, 58.41; O, 9.22; total 99.33 wt.%. The empirical chemical formula is AlF2.6(OH)0.5 which suggests partial substitution of F by OH. Oskarssonite is rhombohedral, space group R3¯ c, with ah = 4.9817(4) A ˚ , c = 12.387(1) A ˚ , Vuc = 266.23(5) A ˚ 3, Z = 6. The five strongest lines in the powder diffraction diagram [d in A ˚ (I) (hkl)] are as follows: 3.54 (100) (012), 2.131 (13) (113), 1.771 (20) (024), 1.59 (15) (116), 1.574 (10) (122). Rietveld refinement confirms the identity of oskarssonite with the synthetic rhombohedral form of AlF3. Its structure can be described as a rhombohedral deformation of the idealized cubic perovskitetype octahedral framework of corner-sharing AlF6 groups. Oskarssonite appears in the surface part of the fumaroles where fluorides are abundant. At greater depths (below 10 cm) sulfates dominate among the fumarolic minerals. In accordance with its occurrence, we surmise that oskarssonite forms in the later stages of the fumarolic activity in an environment poor in alkalies and Mg. Ralstonite (NaxMgxAl1xF3(H2O)y), which, unlike oskarssonite, contains Na and Mg as important constituents, dominated in the first-formed fumaroles, but now, 41 years after the eruption of Eldfell, is only a minor phase. The new mineral is named after the Icelandic volcanologist Niels Oskarsson.

The first single-crystal structure refinement of Ag- and Cu-free heyrovskyite was performed in this study. Crystals investigated were sampled from the high-temperature fumaroles of La Fossa crater of Vulcano, Aeolian Islands, Italy. Electron microprobe analyses gave the average chemical formula (Pb(5.86)Cd(0.03))(Sigma 5.89)Bi(2.04)(S(8.52)Se(0.53)Cl(0.03))(Sigma 9.08), which is very close to the ideal composition of heyrovskyite, Pb(6)Bi(2)S(9). Lattice parameters are a = 13.7498(4), b = 31.5053(8), c = 4.1475(1) angstrom, V = 1796.7(1) angstrom(3), space group Bbmm. The structure refinement converges to R = 4.17% for 1312 reflections with F. &gt; 4 sigma(F(o)). In Ag-free heyrovskyite from Vulcano, as well as in the synthetic Pb(6)Bi(2)S(9), the trigonal prismatic coordinated position Me1, as well as the octahedrally coordinated position Me3 are occupied only by Pb. Me2, also octahedrally coordinated, is dominated by Pb, whereas the octahedra situated at the edges of the octahedral layers (Me4 and Me5) are centered around mixed (Pb,Bi) positions, with almost equal occupancy. The octahedrally coordinated site Me3 was found to incorporate vacancies (0), created by the substitution 3Pb(2+) --&gt; 2Bi(3+)+square, which allows for the observed deviations from the ideal composition, Pb(6)Bi(2)S(9). Selenium is preferentially ordered at the fivefold-coordinated anionic sites. Taking into account vacancies, as well as Se for S substitutions the structural formula of Ag-free heyrovskyite from Vulcano is Pb(5.82)Bi(2.12)square(0.06)S(8.70)Se(0.30). Comparison with the Ag-bearing heyrovskyite structures shows that during the 2 Pb --&gt; Ag(Cu)+Bi substitution the increased content of Bi is incorporated preferentially in the Me5 site until 2/3 Bi occupancy and thereafter in the two central octahedrally coordinated sites (Me2 and Me3). Silver occupies exclusively marginal octahedrally coordinated Me4 site like in the other members of the lillianite homologous series. The observed crystal chemical characteristics of the Ag-free heyrovskyite are in accordance with a model suggested by Callegari and Boiocchi, which describes the monoclinic form, aschamalmite, as an ordered polymorph of Pb(6)Bi(2)S(9), and heyrovskyite as a fully disordered polymorph of the same compound. Ag incorporation is expected to increase the Pb/Bi disorder and to stabilize the orthorhombic heyrovskyite form.

The crystal structure of balićžunićite, Bi2O(SO4)2, a new mineral species from "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 P-1, with lattice parameters a 6.7386(3), b 11.1844(5), c 14.1754(7) Å, α 80.082(2){degree sign}, β 88.462(2){degree sign}, γ 89.517(2){degree sign}, V 1052.01(8) Å3 and Z = 6. The crystal structure consists of 6 independent Bi sites, 6 S sites and 27 O sites of which 3 are oxo oxygen atoms not bonded to sulphur. Bi and S atoms are arranged close to an eutectic pattern parallel to the (100) crystal planes. 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 over 535oC. 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-sulphate oxygen bonds, forming infinite [100] rods with composition Bi5O3(SO4)51-. One sixths of Bi atoms do not participate in trapezoids, but form with additional SO42- groups rows of composition BiSO41+, also parallel to [100]. [Bi5O3(SO4)51-] rods form infinite layers parallel to the crystal plane (010) with [BiSO41+] 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 Bi coordinations present in balićžunićite.