scholarly journals Manganoarrojadite-(KNa), KNa5MnFe13Al(PO4)11(PO3OH)(OH)2, a new arrojadite-group mineral from the Palermo No. 1 mine, New Hampshire, USA

2020 ◽  
pp. 1-9
Author(s):  
Inna Lykova ◽  
Ralph Rowe ◽  
Glenn Poirier ◽  
Kate Helwig ◽  
Henrik Friis
Keyword(s):  
New Hampshire ◽  
Structural Formula ◽  
Structure Type ◽  
X Ray Diffraction ◽  
Cation Site ◽  
Group Mineral ◽  
X Ray ◽  
Mohs Hardness ◽  
Dominant Cation ◽  
Pale Green

Abstract A new arrojadite-group mineral manganoarrojadite-(KNa), ideally KNa5MnFe13Al(PO4)11(PO3OH)(OH)2, was found in a phosphate-bearing granite pegmatite at the Palermo No. 1 mine, New Hampshire, USA. It forms anhedral grains up to 1 × 1.5 cm in size combined in aggregates with vivianite, goyazite, quartz and calcite. The mineral is olive green with a pale green streak and vitreous to greasy lustre. The cleavage is good in one direction. The Mohs hardness is 4½. Dcalc is 3.53 g/cm3. Manganoarrojadite-(KNa) is optically biaxial (–), α = 1.658(2), β = 1.666(2), γ = 1.670(2), 2Vmeas. = 67(1)° and 2Vcalc. = 70° (589 nm). The infrared spectrum is reported. The composition (wt.%) is Na2O 6.97, K2O 1.78, CaO 0.31, MgO 2.17, MnO 12.30, FeO 31.17, Al2O3 2.43, P2O5 40.48, F 0.30, H2O 1.32, O = F2 –0.13, total 99.10. The empirical formula calculated on the basis of 12 P and (O+OH+F) = 50 apfu is Na4.73K0.80Ca0.12Mg1.13Mn2+3.65Fe2+9.13Al1.00P12.00O46.59OH3.08F0.33. The ideal structural formula is A 1K A 2Na B 1Na B 2NaNa1,2Na2Na3□ C Mn M Fe13Al(PO4)11(PO3OH) W (OH)2. The mineral is monoclinic, Cc, a = 16.5345(3), b = 10.0406(2), c = 24.6261(5) Å, β = 105.891(2)°, V = 3932.09(14) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 5.902(24)(202), 5.025(24)(020), 3.208(47)(206, $\;\bar{1}$ 32), 3.048(100)( $\bar{5}$ 14, $\bar{4}$ 24), 2.758(24)( $\bar{6}$ 02) and 2.704(70)(226). The crystal structure, refined from single-crystal X-ray diffraction data (R1 = 0.025), is of the arrojadite structure type. Manganoarrojadite-(KNa) is the first arrojadite-group mineral with Mn dominant on the site usually occupied by Ca and without Ca as the dominant cation at any cation site.

Nickeltsumcorite, Pb(Ni,Fe3+)2(AsO4)2 (H2O,OH)2, a new tsumcorite-group mineral from Lavrion, Greece

2016 ◽  
Vol 80 (2) ◽  
pp. 337-346
Author(s):  
Igor V. Pekov ◽  
Nikita V. Chukanov ◽  
Dmitry A. Varlamov ◽  
Dmitry I. Belakovskiy ◽  
Anna G. Turchkova ◽  
...  
Keyword(s):  
Structure Type ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Yellow Light ◽  
Cation Composition ◽  
Group Mineral ◽  
X Ray ◽  
Mohs Hardness ◽  
Mn Oxides

AbstractA new tsumcorite-group mineral, nickeltsumcorite, Pb(Ni,Fe3+)2(AsO4)2(H2O,OH)2, the Ni-dominant analogue of tsumcorite and cobalttsumcorite, was found in the oxidation zone of a hydrothermal orebody containing gersdorffite and galena at the Km-3 mine, Lavrion, Attikí Prefecture, Greece. It is associated with annabergite, nickellotharmeyerite, nickelaustinite, gaspéite, calcite, dolomite, aragonite, quartz, goethite, cerussite, arseniosiderite, mimetite, oxyplumboroméite and Mn oxides/hydroxides. Nickeltsumcorite occurs as open-work aggregates and interrupted crusts up to 3 mm × 5 mm in area and up to 0.2 mm thick. They typically consist of coarse radial spherulites or dense concentric nodules up to 0.15 mm in diameter. Bunches or hemispherical clusters of crude individuals and separate imperfect, elongated crystals (up to 0.02 mm long) are also observed. Nickeltsumcorite is yellow, brownish-yellow, light brown or brown, with a yellow streak and a vitreous lustre. The Mohs hardness is ∼4. The mineral is brittle; one direction of distinct cleavage is observed under the microscope. D(calc.) = 5.02 g cm–3. Nickeltsumcorite is optically biaxial (–), α = 1.82(2), β = 1.87(1), γ = 1.90(1), 2V(obs.) is large. The chemical composition (wt.%, electron-microprobe data, H2O by difference) is CaO 2.79, PbO 28.12, MgO 0.30, CoO 0.15, NiO 17.39, ZnO 0.76, Mn2O3 0.57, Fe2O3 6.83, As2O5 38.17, H2O 4.92, total 100.00. The empirical formula, calculated based on 10 O apfu, is (Pb0.76Ca0.30)∑1.06(Ni1.39Fe3+0.51Zn0.06Mn3+0.04 Mg0.04Co0.01)∑2.05As1.99O7.97[(H2O)1.25(OH)0.78]. The strongest reflections in the powder X-ray diffraction pattern [d,Å(I)(hkl)] are 4.64 (100) (1̄11), 4.47 (41)(2̄01), 3.238 (82)(1̄12), 3.008(60)(201), 2.859(41)(021), 2.545(79)(3̄12, 112), 2.545 (79)(3̄12, 112) and 2.505 (61)(220, 2̄03). The cation composition, powder Xray diffraction data and IR spectrum show that nickeltsumcorite belongs to the tsumcorite structure type. The new mineral is monoclinic, space group C2/m, a = 9.124(8), b = 6.339(3), c = 7.567(7) Å, β = 115.19(6)°, V = 396.0(7) Å3 and Z = 2. Nickeltsumcorite forms a solid-solution series with nickellotharmeyerite.

scholarly journals Norilskite, (Pd,Ag)7Pb4, a new mineral from Noril'sk-Talnakh deposit, Russia

2017 ◽  
Vol 81 (3) ◽  
pp. 531-541 ◽  
Author(s):  
A. Vymazalová ◽  
F. Laufek ◽  
S. F. Sluzhenikin ◽  
C. J. Stanley
Keyword(s):  
Polarized Light ◽  
Structure Type ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Strong Anisotropy ◽  
Average Composition ◽  
Group Mineral ◽  
X Ray ◽  
Mohs Hardness ◽  
Talnakh Deposit

AbstractNorilskite, (Pd,Ag)7Pb4 is a new platinum-group mineral discovered in the Mayak mine of the Talnakh deposit, Russia. It forms anhedral grains in aggregates (up to ∼400 μm) with polarite, zvyagintsevite, Pd-rich tetra-auricupride, Pd-Pt bearing auricupride,Ag-Au alloys, (Pb,As,Sb) bearing atokite, mayakite, Bi-Pb-rich kotulskite and sperrylite in pentlandite, cubanite and talnakhite. Norilskite is brittle, has a metallic lustre and a grey streak. Values of VHN20 fall between 296 and 342 kg mm–2, with a mean valueof 310 kg mm–2, corresponding to a Mohs hardness of ∼4. In plane-polarized light, norilskite is orange-brownish pink, has moderate to strong bireflectance, orange-pink to greyish-pink pleochroism, and strong anisotropy; it exhibits no internal reflections. Reflectancevalues of norilskite in air (Ro, Re' in %) are: 51.1, 48.8 at 470 nm, 56.8, 52.2 at 546 nm, 59.9, 53.5 at 589 nm and 64.7, 55.5 at 650 nm. Sixteen electronmicroprobe analyses of natural norilskite gave an average composition: Pd 44.33, Ag 2.68, Bi 0.33 and Pb 52.34, total99.68 wt.%, corresponding to the empirical formula (Pd6.56Ag0.39)∑6.95(Pb3.97Bi0.03)∑4.00 based on 4 Pb + Bi atoms; the average of eight analyses on synthetic norilskite is: Pd 42.95, Ag 3.87 and Pb 53.51, total 100.33wt.%, corresponding to (Pd6.25Ag0.56)∑6.81Pb4.00. The mineral is trigonal, space group P3121, with a = 8.9656(4), c = 17.2801(8) Å, V = 1202.92(9) Å3 and Z = 6. The crystalstructure was solved and refined from the powder X-ray diffraction data of synthetic (Pd,Ag)7Pb4. Norilskite crystallizes in the Ni13Ga3Ge6 structure type, related to nickeline. The strongest lines in the powder X-ray diffraction patternof synthetic norilskite [d in Å (I) (hkl)] are: 3.2201(29)(023,203), 2.3130(91)(026,206), 2.2414(100)(220), 1.6098(28)(046,406), 1.3076(38)(246,462), 1.2942(18)(600), 1.2115(37)(22.12,12.13), 0.9626(44) (06.12,60.12). The mineral is named for the locality, the Noril'sk district in Russia.

New arsenate minerals from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. IX. Arsenatrotitanite, NaTiO(AsO4)

2018 ◽  
Vol 83 (03) ◽  
pp. 453-458 ◽  
Author(s):  
Igor V. Pekov ◽  
Natalia V. Zubkova ◽  
Atali A. Agakhanov ◽  
Dmitry I. Belakovskiy ◽  
Marina F. Vigasina ◽  
...  
Keyword(s):  
Scoria Cone ◽  
Structure Type ◽  
Fissure Eruption ◽  
Single Crystal Xrd ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Group Mineral ◽  
X Ray ◽  
Tolbachik Volcano ◽  
Mohs Hardness

AbstractThe new durangite-group mineral arsenatrotitanite, ideally NaTiO(AsO4), was found in the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with orthoclase, tenorite, hematite, johillerite, bradaczekite, badalovite, calciojohillerite, arsmirandite, tilasite, svabite, cassiterite, pseudobrookite, rutile, sylvite, halite, aphthitalite, langbeinite and anhydrite. Arsenatrotitanite occurs as prismatic, tabular, lamellar or acicular crystals up to 0.3 mm × 0.8 mm × 2 mm. They are separated or combined in open-work aggregates up to 2 mm across or interrupted crusts up to 2 mm × 5 mm in area and up to 0.3 mm thick. Arsenatrotitanite is transparent, brownish red to pale pinkish-reddish or almost colourless, with vitreous lustre. It is brittle and the Mohs’ hardness is ~5½. Cleavage is perfect on {110} and the fracture is stepped. Dcalc is 3.950 g cm–3. Arsenatrotitanite is optically biaxial (+), α = 1.825(5), β = 1.847(6), γ = 1.896(6) (589 nm) and 2Vmeas. = 70(5)°. Chemical composition (wt.%, electron-microprobe) is: Na2O 12.26, CaO 3.10, Al2O3 4.39, Fe2O3 9.57, TiO2 17.11, SnO2 1.03, As2O5 50.17, F 3.29, O = F –2.39, total 99.53. The empirical formula based on 5 (O + F) apfu is (Na0.91Ca0.13)Σ1.04(Ti0.49Fe3+0.27Al0.20Sn0.02)Σ0.98(As1.00O4.00)(O0.60F0.40). Arsenatrotitanite is monoclinic, C2/c, a = 6.6979(3), b = 8.7630(3), c = 7.1976(3) Å, β = 114.805(5)°, V = 383.48(3) Å3 and Z = 4. The strongest reflections of the powder X-ray diffraction (XRD) pattern [d,Å(I)(hkl)] are: 4.845(89)($\bar{1} {11}}$), 3.631(36)(021), 3.431(48)(111), 3.300(100)($\bar{1} {12}}$), 3.036(100)(200), 2.627(91)(130) and 2.615(57)(022). The crystal structure was solved from single-crystal XRD data with R = 1.76%. Arsenatrotitanite belongs to the titanite/durangite structure type. It is named as an arsenate of sodium (natrium in Latin) and titanium isostructural with titanite.

Sergevanite, Na15(Ca3Mn3)(Na2Fe)Zr3Si26O72(OH)3·H2O, a new eudialyte-group mineral from the Lovozero alkaline massif, Kola Peninsula

2020 ◽  
Vol 58 (4) ◽  
pp. 421-436 ◽  
Author(s):  
Nikita V. Chukanov ◽  
Sergey M. Aksenov ◽  
Igor V. Pekov ◽  
Dmitriy I. Belakovskiy ◽  
Svetlana A. Vozchikova ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Structural Data ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
Eudialyte Group ◽  
Group Mineral ◽  
X Ray ◽  
Mohs Hardness ◽  
Alkaline Massif

ABSTRACT The new eudialyte-group mineral sergevanite, ideally Na15(Ca3Mn3)(Na2Fe)Zr3Si26O72(OH)3·H2O, was discovered in highly agpaitic foyaite from the Karnasurt Mountain, Lovozero alkaline massif, Kola Peninsula, Russia. The associated minerals are microcline, albite, nepheline, arfvedsonite, aegirine, lamprophyllite, fluorapatite, steenstrupine-(Ce), ilmenite, and sphalerite. Sergevanite forms yellow to orange-yellow anhedral grains up to 1.5 mm across and the outer zones of some grains of associated eudialyte. Its luster is vitreous, and the streak is white. No cleavage is observed. The Mohs' hardness is 5. Density measured by equilibration in heavy liquids is 2.90(1) g/cm3. Calculated density is equal to 2.906 g/cm3. Sergevanite is nonpleochroic, optically uniaxial, positive, with ω = 1.604(2) and ε = 1.607(2) (λ = 589 nm). The infrared spectrum is given. The chemical composition of sergevanite is (wt.%; electron microprobe, H2O determined by HCN analysis): Na2O 13.69, K2O 1.40, CaO 7.66, La2O3 0.90, Ce2O3 1.41, Pr2O3 0.33, Nd2O3 0.64, Sm2O3 0.14, MnO 4.15, FeO 1.34, TiO2 1.19, ZrO2 10.67, HfO2 0.29, Nb2O5 1.63, SiO2 49.61, SO3 0.77, Cl 0.23, H2O 4.22, –O=Cl –0.05, total 100.22. The empirical formula (based on 25.5 Si atoms pfu, in accordance with structural data) is H14.46Na13.64K0.92Ca4.22Ce0.27La0.17Nd0.12Pr0.06Sm0.02Mn1.81Fe2+0.58Ti0.46Zr2.67Hf0.04Nb0.38Si25.5S0.30Cl0.20O81.35. The crystal structure was determined using single-crystal X-ray diffraction data. The new mineral is trigonal, space group R3, with a = 14.2179(1) Å, c = 30.3492(3) Å, V = 5313.11(7) Å3, and Z = 3. In the structure of sergevanite, Ca and Mn are ordered in the six-membered ring of octahedra (at the sites M11 and M12), and Na dominates over Fe2+ at the M2 site. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 7.12 (70) (110), 5.711 (43) (202), 4.321 (72) (205), 3.806 (39) (033), 3.551 (39) (220, 027), 3.398 (39) (313), 2.978 (95) (), 2.855 (100) (404). Sergevanite is named after the Sergevan' River, which is near the discovery locality.

Natropharmacoalumite, NaAl4[(OH)4(AsO4)3].4H2O, a new mineral of the pharmacosiderite supergroup and the renaming of aluminopharmacosiderite to pharmacoalumite

2010 ◽  
Vol 74 (5) ◽  
pp. 929-936 ◽  
Author(s):  
M. S. Rumsey ◽  
S. J. Mills ◽  
J. Spratt
Keyword(s):  
Empirical Formula ◽  
Direct Methods ◽  
Structure Type ◽  
New Mineral ◽  
Gold Mine ◽  
Nomenclature System ◽  
Cubic Crystals ◽  
X Ray ◽  
Mohs Hardness ◽  
Dominant Cation

AbstractNatropharmacoalumite, ideally NaAl4[(OH)4(AsO4)3]·4H2O, is a new mineral from the Maria Josefa Gold mine, Rodalquilar, Andalusia region, Spain. It occurs as colourless, intergrown cubic crystals with chenevixite, kaolinite, jarosite and indeterminable mixtures of Fe and Sb oxyhydroxides. Individual crystals are up to 0.5 mm on edge, although crystals are more commonly ˜0.25 mm across and occur in patchy aggregates several millimetres across. The mineral is transparent with a vitreous to adamantine lustre. It is brittle with an imperfect cleavage, irregular fracture and a white streak. The Mohs hardness is ˜2.5 with a calculated densityof 2.56 g cm–3 for the empirical formula. Electron microprobe analyses yielded Na2O 2.52%, K2O 1.49%, Al2O3 29.50%, As2O5 48.84% and H2O was calculated in line with the structural analysis as 16.28% totalling 98.63%. The empirical formula, based upon 20.21 oxygen atoms, is [Na0.57K0.22(H3O)0.21]Σ1.00Al4.05(As2.97O12)(OH)4·4H2O. The five strongest lines in the X-ray powder diffraction pattern are [dobs(Å), Iobs,(hkl)]: 7.759,100,(100); 4.473,40,(111); 3.870,50,(200); 2.446,9,(301); 2.331,12,(311). Natropharmacoalumite is cubic, space group with a = 7.7280(3) Å, V = 461.53(3) Å3 and Z = 1. The crystal structure was solved by direct methods and refined to R1 = 0.063 for 295 reflections with F>4σ(F). The structure conforms broadly to that of the general pharmacosiderite structure type, with Na as the dominant cation in cavities of strongly distorted Al octahedra and As tetrahedra. A new group nomenclature system for minerals with the pharmacosiderite structure has been established, including the renaming of aluminopharmacosiderite to pharmacoalumite.

New arsenate minerals from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. I. Yurmarinite, Na7(Fe3+,Mg,Cu)4(AsO4)6

2014 ◽  
Vol 78 (4) ◽  
pp. 905-917 ◽  
Author(s):  
I. V. Pekov ◽  
N. V. Zubkova ◽  
V. O. Yapaskurt ◽  
D. I. Belakovskiy ◽  
I. S. Lykova ◽  
...  
Keyword(s):  
Scoria Cone ◽  
Ore Deposits ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Tolbachik Volcano ◽  
Mohs Hardness ◽  
Heteropolyhedral Framework ◽  
Pale Green

AbstractA new mineral, yurmarinite, Na7(Fe3+,Mg,Cu)4(AsO4)6, occurs in sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. It is associated with hatertite, bradaczekite, johillerite, hematite, tenorite, tilasite and aphthitalite. Yurmarinite occurs as well-shaped, equant crystals up to 0.3 mm in size, their clusters up to 0.5 mm and thin, interrupted crystal crusts up to 3 mm × 3 mm on volcanic scoria. Crystal forms are {101}, {011}, {100}, {110} and {001}. Yurmarinite is transparent, pale green or pale yellowish green to colourless. The lustre is vitreous and the mineral is brittle. The Mohs hardness is ∼4½. One direction of imperfect cleavage was observed, the fracture is uneven. D(calc.) is 4.00 g cm−3. Yurmarinite is optically uniaxial (−), ω = 1.748(5), ε = 1.720(3). The Raman spectrum is given. The chemical composition (wt.%, electron microprobe data) is Na2O 16.85, K2O 0.97, CaO 1.28, MgO 2.33, MnO 0.05, CuO 3.17, ZnO 0.97, Al2O3 0.99, Fe2O3 16.44, TiO2 0.06, P2O5 0.12, V2O5 0.08, As2O5 56.68, total 99.89. The empirical formula, calculated on the basis of 24 O atoms per formula unit, is (Na6.55Ca0.28K0.22)S7.05(Fe2.483+Mg0.70Cu0.48Al0.23Zn0.14Ti0.01Mn0.01)S4.05(As5.94P0.02V0.01)S5.97O24. Yurmarinite is rhombohedral, Rc, a = 13.7444(2), c = 18.3077(3) Å, V = 2995.13(8) Å3, Z = 6. The strongest reflections in the X-ray powder pattern [d, Å (I)(hkl)] are: 7.28(45)(012); 4.375(33)(211); 3.440(35)(220); 3.217(36)(131,214); 2.999(30)(223); 2.841(100)(125); 2.598(43)(410). The crystal structure was solved from single-crystal X-ray diffraction data to R = 0.0230. The structure is based on a 3D heteropolyhedral framework formed by M4O18 clusters (M = Fe3+ > Mg,Cu) linked with AsO4 tetrahedra. Sodium atoms occupy two octahedrally coordinated sites in the voids of the framework. In terms of structure, yurmarinite is unique among minerals but isotypic with several synthetic compounds with the general formula (Na7–x☐x)(M3+x3+M1–x2+)(T5+O4)2 in which T = As or P, M3+ = Fe or Al, M2+ = Fe and 0 ≤ x ≤ 1. The mineral is named in honour of the Russian mineralogist, petrologist and specialist in studies of ore deposits, Professor Yuriy B. Marin (b. 1939). The paper also contains a description of the Arsenathaya fumarole and an overview of arsenate minerals formed in volcanic exhalations.

scholarly journals Synthesis and superstructural characterization of Fe1.89Mo4.11O7

1994 ◽  
Vol 9 (4) ◽  
pp. 891-897 ◽  
Author(s):  
George L. Schimek ◽  
Robert E. McCarley ◽  
L. Scott Chumbley
Keyword(s):  
Structure Type ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Cation Site ◽  
X Ray ◽  
Transmission Electron ◽  
The Family ◽  
Regular Arrangement ◽  
Cation Sites

Superstructuring in the new compound Fe1.89Mo4.11O7 has been elucidated by transmission electron microscopy. This compound is a member of the family M2MO4O7 and has both iron and molybdenum atoms occupying octahedrally coordinated sites in the structure, represented by Fet(Fe0.89M0.11)0Mo4O7. The superstructuring, detected only by electron diffraction, involved tripling of all three lattice parameters of the subcell. The subcell was structured by single crystal x-ray diffraction [Imma, no. 74, a = 5.9793(5) Å, b = 5.7704(4) Å, and c = 17.036(1) Å]. This structure type contains a close-packed arrangement of Mo4O7 units, which are infinite chains of trans edge-shared molybdenum octahedra running parallel to b*. Two different coordination environments are observed for the cations. Parallel to the a* direction, infinite edge-sharing MO6 (M = 89% Fe or 11% Mo) octahedra are observed. The second cation site, with nearly tetrahedral coordination by oxygen, is filled solely by iron. The superstructure can be rationalized by a regular arrangement of iron and molybdenum atoms in the octahedrally coordinated cation sites.

scholarly journals Gobelinite, the Co analogue of ktenasite from Cap Garonne, France, and Eisenzecher Zug, Germany

2020 ◽  
Vol 32 (6) ◽  
pp. 637-644
Author(s):  
Stuart J. Mills ◽  
Uwe Kolitsch ◽  
Georges Favreau ◽  
William D. Birch ◽  
Valérie Galea-Clolus ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Old French ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations ◽  
Jahn Teller ◽  
Mohs Hardness ◽  
Pale Green

Abstract. The new mineral gobelinite, ideally CoCu4(SO4)2(OH)6⚫6H2O, is a new member of the ktenasite group and the Co analogue of ktenasite, ZnCu4(SO4)2(OH)6⚫6H2O. It occurs at Cap Garonne (CG), Var, France (type locality), and Eisenzecher Zug (EZ), Siegerland, North Rhine-Westphalia, Germany (cotype locality). The mineral forms pale green, bluish green or greyish green, blocky to thin, lath-like crystals. They are transparent and non-fluorescent, with a vitreous, sometimes also pearly, lustre and a white streak having a pale-green cast. Mohs hardness is about 2.5. The crystals are brittle with an irregular fracture; no cleavage was observed. D(meas.) is 2.95(2) and D(calc.) is 2.907 g cm−3 (for empirical formula, CG). Common associates are brochantite and various other hydrated metal sulfates. Electron-microprobe analyses of the CG material yielded (wt. %) CuO 42.45, CoO 6.58, NiO 3.37, ZnO 3.14, SO3 22.12, and H2O 22.62 (calculated on structural grounds), and total = 100.30 wt. %, giving the empirical formula (based on 20 O atoms) (Co0.63Ni0.32Zn0.28Cu3.83)Σ5.06S1.98O20H18.00. The simplified formula is (Co,Ni)(Cu,Zn)4(SO4)2(OH)6⚫6H2O, and the endmember formula is CoCu4(SO4)2(OH)6⚫6H2O. Scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS) analyses of the (Zn-free) EZ material gave the simplified average formula (Co0.92Ni0.21Mg0.01Cu3.79)Σ4.93(SO4)2.08(OH)6⚫6H2O. Optically, gobelinite (CG) is biaxial negative, with α=1.576(2), β=1.617(2) and γ=1.630(2); 2Vmeas=58(4)∘ and 2Vcalc=57.5∘. Dispersion is weak, r>v; orientation is X=β, Y=γ and Z≈α, with strong pleochroism X equaling colourless, Y equaling green and Z equaling pale green. The mineral is monoclinic, space group P21∕c, with a=5.599(1), b=6.084(1), c=23.676(5) Å, β=95.22(3)∘ and V=803.2(3) Å3 (at 100 K; CG) and a=5.611(1), b=6.103(1), c=23.808(5) Å, β=95.18(3)∘ and V=811.9(3) Å3 (at 298 K; EZ), respectively (Z=2). The eight strongest measured powder X-ray diffraction lines (d in Å (I) hkl (CG material)) are 11.870 (100) 002, 5.924 (40) 004, 4.883 (10) 102, 4.825 (15) 013, 3.946 (15) 006, 2.956 (15) 008, 2.663 (20) 202 and 2.561 (15) 1‾23. Single-crystal structure determinations gave R1=0.0310 (CG) and 0.0280 (EZ). The atomic arrangement is based on brucite-like sheets formed from edge-sharing, Jahn–Teller-distorted (4+2 coordination) CuO6 octahedra. These sheets are decorated on both sides with SO4 tetrahedra and linked via hydrogen bonds to interstitial, fairly regular Co(H2O)6 octahedra. The name alludes to the Old French word gobelin, equivalent to the German word kobold, from which the designation of the element cobalt was derived.

The chemical composition and structure of a 14 Å intergradient mineral in a Korean Ultisol

Clay Minerals ◽  
1991 ◽  
Vol 26 (4) ◽  
pp. 449-461 ◽  
Author(s):  
K. Wada ◽  
Y. Kakuto ◽  
M. A. Wilson ◽  
J. V. Hanna
Keyword(s):  
Sodium Citrate ◽  
Interlayer Space ◽  
Structural Formula ◽  
Layer Silicate ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Composition And Structure ◽  
Dominant Cation

AbstractAn intergradient 14 Å mineral showing X-ray diffraction features of “chloritized” vermiculite in a Korean Ultisol was studied. The structural formula of the whole 2:1 layer-silicate (14 Å mineral and mica) in the Na+-saturated 0·2–0·5 µm fraction was obtained by elemental, thermogravimetric and 29Si and 27Al nuclear magnetic resonance spectroscopic analyses in combination with extraction of the interlayer material from the 14 Å mineral by hot 1/3 m sodium citrate treatment. This formula showed: (1) the 2 : 1 layer contains nearly one Al3+ in four tetrahedral positions, and Al3+ is the dominant cation in the octahedral sheet; (2) K+, exchangeable Na+ and sodium citrate extractable 1 : 1 layer occupy the interlayer space of the 14 Å mineral in similar proportions. Very little interlayer K was replaced by Na+ during the citrate treatment. Possible schemes of alteration of the 2 : 1 layer to the 1 : 1 layer as its interlayer material are discussed.

New arsenate minerals from the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, Russia. XV. Calciojohillerite, NaCaMgMg2(AsO4)3, a member of the alluaudite group

2021 ◽  
pp. 1-9
Author(s):  
Igor V. Pekov ◽  
Natalia N. Koshlyakova ◽  
Atali A. Agakhanov ◽  
Natalia V. Zubkova ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Scoria Cone ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
X Ray Diffraction ◽  
Yellow Light ◽  
X Ray ◽  
Tolbachik Volcano ◽  
Mohs Hardness ◽  
Pale Green ◽  
The Ideal

Abstract The new alluaudite-group mineral calciojohillerite is one of the major arsenates in sublimates of the Arsenatnaya fumarole at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia. In middle zones of the fumarole, calciojohillerite is associated with hematite, tenorite, johillerite, nickenichite, bradaczekite, badalovite, tilasite, lammerite, ericlaxmanite, aphthitalite-group sulfates, langbeinite, calciolangbeinite, anhydrite, sanidine, fluorophlogopite, fluoborite, cassiterite, pseudobrookite, rutile, sylvite and halite. In deep zones it occurs in association with anhydrite, diopside, hematite, svabite, berzeliite, schäferite, forsterite, magnesioferrite, ludwigite, rhabdoborite-group fluoroborates, powellite, baryte, fluorapatite, udinaite, arsenudinaite and paraberzeliite. Calciojohillerite forms prismatic crystals up to 1 cm long, their aggregates and crystal crusts up to 0.5 m2. It is transparent, colourless, pale green, pale yellow, light blue, pale lilac or pink, with vitreous lustre. The mineral is brittle, with imperfect cleavage. The Mohs hardness is 3½. Dcalc is 3.915 g cm–3. Calciojohillerite is optically biaxial (–), α = 1.719(3), β = γ = 1.732(3); 2Vmeas. = 15(10)°. Chemical composition (wt.%, electron-microprobe; holotype) is: Na2O 7.32, K2O 0.10, CaO 6.82, MgO 20.31, MnO 0.68, CuO 0.27, ZnO 0.02, Al2O3 0.56, Fe2O3 3.53, TiO2 0.01, SiO2 0.03, P2O5 1.25, V2O5 0.10, As2O5 58.77, SO3 0.13, total 99.90. The empirical formula based on 12 O atoms is (Na1.30K0.01Ca0.67Mg2.78Mn0.05Cu0.02Al0.06Fe3+0.24)Σ5.13(As2.83P0.10S0.01V0.01)Σ2.95O12. Calciojohillerite is monoclinic, C2/c, a = 11.8405(3), b = 12.7836(2), c = 6.69165(16) Å, β = 112.425(3)°, V = 936.29(4) Å3 and Z = 4. The crystal structure was solved from single-crystal X-ray diffraction data, R1 = 0.0227. Calciojohillerite is isostructural with other alluaudite-group minerals. Its simplified crystal chemical formula is A (1)Ca A (1)′□ A (2)□ A (2)′Na M (1)Mg M (2)Mg2(AsO4)3 (□ = vacancy). The idealised formula is NaCaMg3(AsO4)3, or, according to the nomenclature of alluaudite-group arsenates, NaCaMgMg2(AsO4)3. Calciojohillerite is named as an analogue of johillerite NaCu2+MgMg2(AsO4)3 with species-defining Ca instead of Cu in the ideal formula.

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