scholarly journals Zinkgruvanite, Ba<sub>4</sub>Mn<sup>2+</sup><sub>4</sub>Fe<sup>3+</sup><sub>2</sub>(Si<sub>2</sub>O<sub>7</sub>)<sub>2</sub>(SO<sub>4</sub>)<sub>2</sub>O<sub>2</sub>(OH)<sub>2</sub>, a new ericssonite-group mineral from the Zinkgruvan Zn-Pb-Ag-Cu deposit, Askersund, Örebro County, Sweden

2021 ◽  
Vol 33 (6) ◽  
pp. 659-673
Author(s):  
Fernando Cámara ◽  
Dan Holtstam ◽  
Nils Jansson ◽  
Erik Jonsson ◽  
Andreas Karlsson ◽  
...  
Keyword(s):  
Electron Probe ◽  
High Salinity ◽  
Regional Metamorphism ◽  
New Mineral ◽  
Drill Core ◽  
Unit Cell Parameters ◽  
Titanium Silicate ◽  
X Ray ◽  
Cell Parameters ◽  
Electron Probe Microanalyser

Abstract. Zinkgruvanite, ideally Ba4Mn42+Fe23+(Si2O7)2(SO4)2O2(OH)2, is a new member of the ericssonite group, found in Ba-rich drill core samples from a sphalerite- and galena- and diopside-rich metatuffite succession from the Zinkgruvan mine, Örebro County, Sweden. Zinkgruvanite is associated with massive baryte, barytocalcite, diopside and minor witherite, cerchiaraite-Al, and sulfide minerals. It occurs as subhedral to euhedral flattened and elongated crystals up to 4 mm. It is almost black and semi-opaque with a dark-brown streak. The lustre is vitreous to sub-adamantine on crystal faces and resinous on fractures. The mineral is brittle with an uneven fracture. VHN100=539, and HMohs ≈ 4.5. In thin fragments, it is reddish-black, translucent and optically biaxial (+), 2Vz > 70∘. Pleochroism is strong and deep brown-red (E ⊥ {001} cleavage) to olive-pale-brown. Chemical point analyses by WDS-EPMA (wavelength-dispersive X-ray spectroscopy electron probe microanalyser) together with iron valencies determined from Mössbauer spectroscopy yielded the empirical formula (based on 26 O+OH+F+Cl anions): (Ba4.02Na0.03)Σ4.05(Mn1.79Fe1.562+Fe0.423+Mg0.14Ca0.10Ni0.01Zn0.01)Σ4.03(Fe1.743+Ti0.20Al0.06)Σ2.00Si4(S1.61Si0.32P0.07)Σ1.99O24(OH1.63Cl0.29F0.08)Σ2.00. The mineral is triclinic, in space group P1¯, with unit-cell parameters a=5.3982(1) Å, b=7.0237(1) Å, c=14.8108(4) Å, α= 98.256(2)∘, β= 93.379(2)∘, γ= 89.985(2)∘ and V= 554.75(2) Å3 for Z=1. The eight strongest X-ray powder diffraction lines are the following (d Å (I %; hkl)): 3.508 (70; 103), 2.980(70; 114‾), 2.814 (68; 12‾2), 2.777 (70; 121), 2.699 (714; 200), 2.680 (68; 201‾), 2.125 (100; 124, 204) and 2.107 (96; 2‾21). The crystal structure (R1=0.0379 for 3204 reflections) is an array of TS (titanium silicate) blocks alternating with intermediate blocks. The TS blocks consist of HOH sheets (H for heteropolyhedral and O for octahedral) parallel to (001). In the O sheet, the Mn2+-dominant MO(1,2,3) sites give ideally Mn42+ pfu (per formula unit). In the H sheet, the Fe3+-dominant MH sites and AP(1) sites give ideally Fe23+Ba2 pfu. In the intermediate block, SO4 oxyanions and 11 coordinated Ba atoms give ideally 2× SO4Ba pfu. Zinkgruvanite is related to ericssonite and ferroericssonite in having the same topology and type of linkage of layers in the TS block. Zinkgruvanite is also closely compositionally related to yoshimuraite, Ba4Mn4Ti2(Si2O7)2(PO4)2O2(OH)2, via the coupled heterovalent substitution 2 Ti4++ 2 (PO4)3-→2 Fe3++ 2 (SO4)2− but presents a different type of linkage. The new mineral probably formed during a late stage of regional metamorphism of a Ba-enriched, syngenetic protolith, involving locally generated oxidized fluids of high salinity.

scholarly journals Na-dominant (at the M2 site) eudialyte analogue: crystal structure and indicatory significance

2020 ◽  
Vol 9 ◽  
pp. 19-25
Author(s):  
R. K. Rastsvetaeva ◽  
◽  
N. V. Chukanov ◽  
Ch. Schäfer ◽  
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Eudialyte Group ◽  
X Ray ◽  
Cell Parameters ◽  
Atomic Displacements ◽  
Alkaline Massif

Minerals of the eudialyte group from ultra-agpaitic associations are often characterized by high contents (up to the dominance) of sodium at the M2 site, which is populated with iron in eudialyte. The features of blocky isomorphism with the replacement of IVFe2+ by IVNa and VNa at the M2 micro-region are discussed. Using the methods of electron probe microanalysis, X-ray diffraction and IR spectroscopy, a potentially new mineral, M2Na-dominant analogue of eudialyte from the Ilimaussaq alkaline massif (Greenland), was investigated. Its crystal structure was refined to R = 5.6 % in the anisotropic approximation of atomic displacements using 1095 independent reflections with F > 3(F). The unit-cell parameters are: a = 14.208(1), c = 30.438(1) Å, V = 5321(1) Å3; the space group is R-3m. The idealized formula of the mineral is (Z = 3): (Na,H3O)15Ca6Zr3[Na2Fe][Si26O72](OH)2Cl∙2H2O.

MgCu4(SO4)2(OH)6 · 6H2O, the magnesium analogue of ktenasite from the Casualidad mine near Baños de Alhamilla, Almeria, Spain

2020 ◽  
Author(s):  
Jochen Schlüter ◽  
Thomas Malcherek ◽  
Boriana Mihailova ◽  
Christian Rewitzer ◽  
Rupert Hochleitner ◽  
...  
Keyword(s):  
Refractive Index ◽  
Chemical Composition ◽  
Electron Probe ◽  
New Mineral ◽  
Environmental Sciences ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Perfect Cleavage

The new mineral fehrite (IMA 2018-125a), MgCu4(SO4)2(OH)6 · 6H2O, is a member of the ktenasite group andthe Mg-analogue of ktenasite, ZnCu4(SO4)2(OH)6 · 6H2O. The mineral was found in the Casualidad mine near Baños deAlhamilla, Almeria, Spain, in association with clinoatacamite, kapellasite, gordaite, serpierite, connellite and gypsum.The transparent turquoise-coloured mineral has a vitreous lustre, exhibits a pale blue-green streak and shows distinctpleochroism. It forms radial aggregates of thin lath-like crystals of up to 200 μm in length. Fehrite is not fluorescent. Themonoclinic crystals show a perfect cleavage parallel to {001}. The mineral has a brittle tenacity and an uneven fracture. Thecalculated density is 2.73 g/cm3, the calculated mean refractive index is 1.584. The strongest lines observed in the X-raypowder diffraction pattern are [d in Å/Irel in %/(hkl)] 11.94/100/002, 5.92/31/004, 2.66/12/202, 4.85/11/013, 3.93/11/006and 2.96/10/008. The chemical composition, measured by means of an electron probe micro-analyser, was determined at(wt.%): MgO 5.31, MnO 0.49, CuO 33.12, ZnO 11.48, SO3 26.01, H2Ocalc. 24.63, total 101.04. The empirical formula basedon 20 O pfu., including 6(OH) and 6(H2O), is Mg0.87Cu2.74Zn0.93Mn0.05S2.14O8(OH)6 · 6H2O. The simplified end memberformula is MgCu4(SO4)2(OH)6 · 6H2O which requires MgO 5.92, CuO 46.74, SO3 23.52, H2O 23.82, total 100.00 (wt.%).Fehrite is monoclinic with space group P21/c (#14). Unit cell parameters determined by X-ray single crystal diffraction area = 5.6062(8), b = 6.1294(11), c = 23.834(3) Å, β = 95.29(1)º, V = 815.5(2) Å3, Z = 2. The mineral is isotypic with ktenasitewith Mg in place of Zn. The name is for the late Karl Thomas Fehr (1954 – 2014), Professor of Mineralogy at the Departmentof Geo- and Environmental Sciences at the Ludwig-Maximilians-University Munich, Germany.

Vaughanite, TlHgSb4S7, a new mineral from Hemlo, Ontario, Canada

1989 ◽  
Vol 53 (369) ◽  
pp. 79-83 ◽  
Author(s):  
Donald C. Harris ◽  
Andrew C. Roberts ◽  
Alan J. Criddle
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
Drill Core ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Arterial Blood ◽  
Mohs Hardness ◽  
Simplified Formula

AbstractVaughanite, idealized formula T1HgSb4S7, is a very rare primary constituent of the Golden Giant orebody of the Hemlo gold deposit, Hemlo, Ontario, Canada. It was found in two polished sections from one drill core; as a 450 by 300 µm aggregate associated with pääkkönenite, stibnite, realgar, and native arsenic; and as a 40 µm anhedral grain associated with stibarsen and chalcostibite. Vaughanite is opaque with a metallic lustre and a black streak. No cleavage was observed but parting, produced by indentation, was detected as a series of weak parallel traces. It is brittle, with an even, occasionally arcuate, fracture. VHN25 is 100–115, mean 104. Mohs hardness (calc.) = 3−3½. In refected plane-polarized light in air the bireflectance is weak to moderate; the pleochroism is also weak, from a somewhat greenish grey to slightly darker bluish grey. Anisotropism is moderate to strong, with rotation tints in shades of green, yellow, purplish brown to brown. Reflectance spectra and colour values are tabulated. The colour in air is light grey. Internal reflections are rare but are arterial-blood-red on indentation fractures. X-ray studies have shown that vaughanite is triclinic with refined unit-cell parameters a 9.012 (3), b 13.223 (3), c 5.906 (2) Å, α 93.27 (3)°, β 95.05 (4)°, γ 109.16 (3)°, V 659.46 (80) Å3, a:b:c = 0.6815 : 1 : 0.4466 and Z = 2. The space group choices are P1 (1) or (2), diffraction aspect P*. The five strongest lines in the X-ray powder pattern [d in Å (l) (hkl)] are: 4.343 (30) (), 4.204 (100) (), 3.313 (60) (130), 2.749 (40) (, 131) and 2.315 (30) (, 122). The average of five electron microprobe analyses gave T1 18.3 (2), Hg 17.5 (2), Sb 43.4 (3), As 1.1 (1), S 20.5 (5), total 100.8 wt. %, corresponding, on the basis of total atoms = 13, to T10.98Hg0.95(Sb3.90As0.17)Σ4.07S7.00. The calculated density is 5.56 g/cm3 for the empirical formula and 5.62 g/cm3 for the simplified formula. The mineral is named for Professor David J. Vaughan.

scholarly journals Crystal Structure Refinements of Four Monazite Samples from Different Localities

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1028 ◽  
Author(s):  
M. Mashrur Zaman ◽  
Sytle M. Antao
Keyword(s):  
Crystal Structure ◽  
Electron Probe ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Large Unit Cell ◽  
A Site

This study investigates the crystal chemistry of monazite (APO4, where A = Lanthanides = Ln, as well as Y, Th, U, Ca, and Pb) based on four samples from different localities using single-crystal X-ray diffraction and electron-probe microanalysis. The crystal structure of all four samples are well refined, as indicated by their refinement statistics. Relatively large unit-cell parameters (a = 6.7640(5), b = 6.9850(4), c = 6.4500(3) Å, β = 103.584(2)°, and V = 296.22(3) Å3) are obtained for a detrital monazite-Ce from Cox’s Bazar, Bangladesh. Sm-rich monazite from Gunnison County, Colorado, USA, has smaller unit-cell parameters (a = 6.7010(4), b = 6.9080(4), c = 6.4300(4) Å, β = 103.817(3)°, and V = 289.04(3) Å3). The a, b, and c unit-cell parameters vary linearly with the unit-cell volume, V. The change in the a parameter is large (0.2 Å) and is related to the type of cations occupying the A site. The average <A-O> distances vary linearly with V, whereas the average <P-O> distances are nearly constant because the PO4 group is a rigid tetrahedron.

Arrheniusite-(Ce), CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11, a New Member of the Vicanite Group, from the Östanmossa Mine, Norberg, Sweden

2021 ◽  
Author(s):  
Dan Holtstam ◽  
Luca Bindi ◽  
Paola Bonazzi ◽  
Hans-Jürgen Förster ◽  
Ulf B. Andersson
Keyword(s):  
Structure Refinement ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Epma Data ◽  
X Ray ◽  
Cell Parameters ◽  
Greenish Yellow ◽  
The Ideal

ABSTRACT Arrheniusite-(Ce) is a new mineral (IMA 2019-086) from the Östanmossa mine, one of the Bastnäs-type deposits in the Bergslagen ore region, Sweden. It occurs in a metasomatic F-rich skarn, associated with dolomite, tremolite, talc, magnetite, calcite, pyrite, dollaseite-(Ce), parisite-(Ce), bastnäsite-(Ce), fluorbritholite-(Ce), and gadolinite-(Nd). Arrheniusite-(Ce) forms anhedral, greenish-yellow translucent grains, exceptionally up to 0.8 mm in diameter. It is optically uniaxial (–), with ω = 1.750(5), ε = 1.725(5), and non-pleochroic in thin section. The calculated density is 4.78(1) g/cm3. Arrheniusite-(Ce) is trigonal, space group R3m, with unit-cell parameters a = 10.8082(3) Å, c = 27.5196(9) Å, and V = 2784.07(14) Å3 for Z = 3. The crystal structure was refined from X-ray diffraction data to R1 = 3.85% for 2286 observed reflections [Fo &gt; 4σ(Fo)]. The empirical formula for the fragment used for the structural study, based on EPMA data and results from the structure refinement, is: (Ca0.65As3+0.35)Σ1(Mg0.57Fe2+0.30As5+0.10Al0.03)Σ1[(Ce2.24Nd2.13La0.86Gd0.74Sm0.71Pr0.37)Σ7.05(Y2.76Dy0.26Er0.11Tb0.08Tm0.01Ho0.04Yb0.01)Σ3.27Ca4.14]Σ14.46(SiO4)3[(Si3.26B2.74)Σ6O17.31F0.69][(As5+0.65Si0.22P0.13)Σ1O4](B0.77O3)F11; the ideal formula obtained is CaMg[(Ce7Y3)Ca5](SiO4)3(Si3B3O18)(AsO4)(BO3)F11. Arrheniusite-(Ce) belongs to the vicanite group of minerals and is distinct from other isostructural members mainly by having a Mg-dominant, octahedrally coordinated site (M6); it can be considered a Mg-As analog to hundholmenite-(Y). The threefold coordinated T5 site is partly occupied by B, like in laptevite-(Ce) and vicanite-(Ce). The mineral name honors C.A. Arrhenius (1757–1824), a Swedish officer and chemist, who first discovered gadolinite-(Y) from the famous Ytterby pegmatite quarry.

scholarly journals Crystallochemical aspects of two microlite-group new mineral species

2014 ◽  
Vol 70 (a1) ◽  
pp. C1095-C1095
Author(s):  
Marcelo Andrade ◽  
Javier Ellena ◽  
Daniel Atencio
Keyword(s):  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
New Mineral Species ◽  
Group 1

Fluorcalciomicrolite, Ca1.5Ta2O6F, and hydroxycalciomicrolite, Ca1.5Ta2O6(OH), are new microlite-group [1] minerals found in the Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil. Both occur as octahedral and rhombododecahedral crystals. The crystals are colourless, yellow and translucent, with vitreous to resinous luster. The densities calculated for fluorcalciomicrolite [2] and hydroxycalciomicrolite are 6.160 and 6.176 g/cm3, respectively. The empirical formulae obtained from electron microprobe analysis are (Ca1.07Na0.81□0.12)Σ2(Ta1.84Nb0.14Sn0.02)Σ2[O5.93(OH)0.07]Σ6.00[F0.79(OH)0.21] for fluorcalciomicrolite and (Ca1.48Na0.06Mn0.01)Σ1.55(Ta1.88Nb0.11Sn0.01)Σ2O6[(OH)0.76F0.20O0.04] for hydroxycalmicrolite. Fluorcalciomicrolite is cubic, space group Fd-3m, a = 10.4191(6) Å, V = 1131.07(11) Å3, and Z = 8. Hydroxycalciomicrolite is also cubic; however, the presence of P-lattice is confirmed by the large number of weak reflections observed by X-ray diffraction. As a result, the space group is P4332 and unit-cell parameters are a = 10.4211(8) Å, and V = 1131.72(15) Å3.

A new mineral, zincolibethenite, CuZnPO4OH, a stoichiometric species of specific site occupancy

2005 ◽  
Vol 69 (2) ◽  
pp. 145-153 ◽  
Author(s):  
R. S. W. Braithwaite ◽  
R. G. Pritchard ◽  
W. H. Paar ◽  
R. A. D. Pattrick
Keyword(s):  
Atmospheric Pressure ◽  
Site Occupancy ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Cation Site ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Jahn Teller

AbstractTiny green crystals from Kabwe, Zambia, associated with hopeite and tarbuttite (and probably first recorded in 1908 but never adequately characterized because of their scarcity) have been studied by X-ray diffraction, microchemical and electron probe microanalysis, infrared spectroscopy, and synthesis experiments. They are shown to be orthorhombic, stoichiometric CuZnPO4OH, of species rank, forming the end-member of a solid-solution series to libethenite, Cu2PO4OH, and are named zincolibethenite. The libethenite structure is unwilling to accommodate any more Zn substituting for Cu at atmospheric pressure, syntheses using Zn-rich solutions precipitating a mixture of zincolibethenite with hopeite, Zn3(PO4)2.4H2O. Single-crystal X-ray data confirm that the Cu(II) occupies the Jahn-Teller distorted 6-coordinate cation site in the libethenite lattice, and the Zn(II) occupies the 5-coordinate site. The space group of zincolibethenite is Pnnm, the same as that of libethenite, with unit-cell parameters a = 8.326, b = 8.260, c = 5.877 Å , V = 404.5 Å 3, Z = 4, calculated density = 3.972 g/cm3 (libethenite has a = 8.076, b = 8.407, c = 5.898 Å , V = 400.44 Å 3, Z = 4, calculated density = 3.965 g/cm3). Zincolibethenite is biaxial negative, with 2Vα(calc.) of 49°, r<v, and α = 1.660, β = 1.705, and γ = 1.715 The mineral is named for its relationship to libethenite.

Leisingite, Cu(Mg,Cu,Fe,Zn)2Te6+O6·6H2O, a new mineral species from the Centennial Eureka mine, Juab County, Utah

1996 ◽  
Vol 60 (401) ◽  
pp. 653-657 ◽  
Author(s):  
Andrew C. Roberts ◽  
Lee A. Groat ◽  
Joel D. Grice ◽  
Robert A. Gault ◽  
Martin C. Jensen ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Infrared Absorption Spectrum ◽  
Thin Plates ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Pale Yellow ◽  
Orange Yellow ◽  
New Mineral Species

AbstractLeisingite, ideally Cu(Mg,Cu,Fe,Zn)2Te6+O6·6H2O, is hexagonal, P3 (143), with unit-cell parameters refined from powder data: a = 5.305(1), c = 9.693(6) Å, V = 236.2(2) Å3, c/a = 1.8271, Z = 1. The strongest six reflections of the X-ray powder-diffraction pattern [d in Å (I) (hkl)] are: 9.70 (100) (001), 4.834 (80) (002), 4.604 (60) (100), 2.655 (60) (110), 2.556 (70) (111) and 2.326 (70) (112). The mineral is found on the dumps of the Centennial Eureka mine, Juab County, Utah U.S.A. where it occurs as isolated, or rarely as clusters of, hexagonal-shaped very thin plates or foliated masses in small vugs of crumbly to drusy white to colourless quartz. Associated minerals are jensenite, cesbronite and hematite. Individual crystals are subhedral to euhedral and average less than 0.1 mm in size. Cleavage {001} perfect. Forms are: {001} major; {100}, {110} minute. The mineral is transparent to somewhat translucent, pale yellow to pale orange-yellow, with a pale yellow streak and an uneven fracture. Leisingite is vitreous with a somewhat satiny to frosted appearance, brittle to somewhat flexible and nonfluorescent; H(Mohs) 3–4; D(calc.) 3.41 for the idealized formula; uniaxial negative, ω = 1.803(3), ɛ = 1.581 (calc.). Averaged electron-microprobe analyses yielded CuO 24.71, FeO 6.86, MgO 6.19, ZnO 0.45, TeO3 36.94, H2O (calc.) [21.55], total [96.70] wt.%, leading to the empirical formula based on O = 12. The infrared absorption spectrum shows definite bands for structural H2O with an O-H stretching frequency centered at 3253 cm−1 and a H-O-H flexing frequency centered at 1670 cm−l. The mineral name honours Joseph F. Leising, Reno, Nevada, who helped collect the discovery specimens.

Kurilite – Ag8Te3Se – a new mineral from the Prasolovskoe deposit, Kuril islands, Russian Federation

2010 ◽  
Vol 74 (3) ◽  
pp. 463-468 ◽  
Author(s):  
V. A. Kovalenker ◽  
O. Yu. Plotinskaya ◽  
C. J. Stanley ◽  
A. C. Roberts ◽  
A. M. McDonald ◽  
...  
Keyword(s):  
Russian Federation ◽  
Empirical Formula ◽  
Polarized Light ◽  
New Mineral ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Kunashir Island ◽  
Mohs Hardness

AbstractKurilite, with the simplified formula, Ag8Te3Se, is a new mineral from the Prasolovskoe epithermal Au-Ag deposit, Kunashir Island, Kuril arc, Russian Federation. It occurs as aggregates up to 2 mm in size, composed of brittle xenomorphic grains, up to several μm in size, in quartz, associated with tetrahedrite, hessite, sylvanite and petzite. Kurilite is opaque, grey, with a metallic lustre and a black streak. Under plane-polarized light, kurilite is white with no observed bireflectance, cleavage, or parting observed. Under crossed polars it appears isotropic without internal reflections. Reflectance values in air and in oil, are tabulated. It has a mean VHN (25 g load) of 99.9 kg/mm2 which equates roughly to a Mohs hardness of 3. Electron microprobe analyses yield a mean composition of Ag 63.71, Au 0.29, Te 29.48, Se 5.04, S 0.07, total 98.71 wt.%. The empirical formula (based on 12 atoms) is (Ag7.97Au0.02)Σ7.99Te3.00(Se0.86Te0.12S0.03)Σ1.01. The calculated density is 7.799 g/cm3 (based on the empirical formula and unit-cell parameters refined from single-crystal data). Kurilite is rhombohedral, R3 or , a 15.80(1), c 19.57(6) Å, V 4231(12)Å3, c:a 1.2386, Z = 15. Its crystal structure remains unsolved. The seven strongest lines of the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 3.727(20)(131), 2.996(50)(232), 2.510(30)(226,422), 2.201(100)(128,416,342), 2.152(20)(603), 2.079(30)(253), 2.046(20)(336,434). The mineral is named after the locality.

Flurlite, Zn3Mn2+Fe3+(PO4)3(OH)2·9H2O, a new mineral from the Hagendorf Süd pegmatite, Bavaria, with a schoonerite-related structure

2015 ◽  
Vol 79 (5) ◽  
pp. 1175-1184 ◽  
Author(s):  
I. E. Grey ◽  
E. Keck ◽  
W. G. Mumme ◽  
A. Pring ◽  
C. M. Macrae ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Layer Structure ◽  
New Mineral ◽  
Water Molecules ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
X Ray ◽  
Cell Parameters ◽  
Bright Orange ◽  
Edge Sharing Octahedra

AbstractFlurlite, ideally Zn3Mn2+Fe3+(PO4)3(OH)2·9H2O, is a new mineral from the Hagendorf-Süd pegmatite, Hagendorf, Oberpfalz, Bavaria, Germany. Flurlite occurs as ultrathin (<1 μm) translucent platelets that form characteristic twisted accordion-like aggregates. The colour varies from bright orange red to dark maroon red. Cleavage is perfect parallel to (001). The mineral occurs on mitridatite and is closely associated with plimerite. Other associated minerals are beraunite, schoonerite, parascholzite, robertsite and altered phosphophyllite. The calculated density of flurlite is 2.84 g cm–3. It is optically biaxial (–), α = 1.60(1), β= 1.65(1) and γ = 1.68(1), with weak dispersion and parallel extinction, X ≈ c, Y ≈ a, Z ≈ b. Pleochroism is weak, with colours: X = pale yellow, Y = pale orange, Z = orange brown. Electron microprobe analyses (average of seven) with FeO and Fe2O3 apportioned and H2O calculated on structural grounds, gave ZnO 25.4, MnO 5.28, MgO 0.52, FeO 7.40, Fe2O3 10.3, P2O5 27.2, H2O 23.1, total 99.2 wt.%. The empirical formula, based on 3 P a.p.f.u. is Zn2.5Mn2+0.6Fe2+0.8Mg0.1Fe3+(PO4)3(OH)2·9H2O. Flurlite is monoclinic, P21/m, with the unit-cell parameters (at 100 K) of a = 6.3710(13), b = 11.020(2), c = 13.016(3) Å, β = 99.34 (3)°. The strongest lines in the X-ray powder diffraction pattern are [dobs in Å(I) (hkl)] 12.900(100)(001); 8.375(10)(011); 6.072(14)(101); 5.567(8)(012); 4.297(21)(003); 2.763(35)(040). Flurlite (R1 = 0.057 for 995 F > 4σ(F)) has a heteropolyhedral layer structure, with layers parallel to (001) and with water molecules packing between the layers. The slab-like layers contain two types of polyhedral chains running parallel to [100]: (a) chains of edge-sharing octahedra containing predominantly Zn and (b) chains in which Fe3+-centred octahedra share their apices with dimers comprising Zn-centred trigonal bipyramids sharing an edge with PO4 tetrahedra. The two types of chains are interconnected by corner-sharing along [010]. A second type of PO4 tetrahedron connects the chains to MnO2(H2O)4 octahedra along [010] to complete the structure of the (001) slabs. Flurlite has the same stoichiometry as schoonerite, but with dominant Zn rather than Fe2+ in the edge-shared chains. Schoonerite has a similar heteropolyhedral layer structure with the same layer dimensions 6.4 × 11.1 Å. The different symmetry (orthorhombic, Pmab) for schoonerite reflects a different topology of the layers.

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