Viteite, Pd5InAs, a new mineral from the Monchetundra layered intrusion, Kola Peninsula, Russia

2020 ◽  
Vol 58 (3) ◽  
pp. 395-402
Author(s):  
A. Vymazalová ◽  
F. Laufek ◽  
T.L. Grokhovskaya ◽  
C.J. Stanley
Keyword(s):  
Kola Peninsula ◽  
Empirical Formula ◽  
Polarized Light ◽  
Layered Intrusion ◽  
Structure Type ◽  
New Mineral ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxygenated Compounds

ABSTRACT Viteite, Pd5InAs, is a new mineral discovered in the Monchetundra layered intrusion, Kola Peninsula, Russia. It forms euhedral grains about 0.5 to 10 μm in size intergrown with irarsite (IrAsS), hollingworthite (RhAsS), zvyagintsevite (Pd3Pb), Au-Ag alloys, and tulameenite (Pt2CuFe), that are replaced by Pt-Pd-Fe-Cu alloys and Pt-Pd-Fe-Cu oxygenated compounds, all of which are embedded in chalcocite, goethite, and covellite. Viteite is brittle and has a metallic luster. In plane-polarized light, viteite is bright pinkish-white. The mineral is weakly anisotropic with rotation tints blue to pinkish brown; it exhibits no internal reflections. Reflectance values of viteite in air (R1, R2 in %) are 55.7, 54.0 at 470 nm; 59.2, 58.4 at 546 nm; 60.0, 60.4 at 589 nm; and 60.0, 62.6 at 650 nm. Eight electron-microprobe analyses of viteite give an average composition of Pd 71.90, Pt 1.60, Fe 0.98, Cu 0.59, In 11.48, Hg 1.42, Pb 0.40, As 10.70, total 99.07 wt.%, corresponding to the empirical formula (Pd4.92Pt0.06)Σ4.98(In0.73Fe0.12Cu0.07Hg0.05Pb0.01)Σ0.98As1.04 based on 7 atoms; the average of 12 analyses of its synthetic analogue is: Pd 73.72, In 16.37, As 9.80, total 99.90 wt.%, corresponding to Pd5.02In1.03As0.95. The density, calculated on the basis of the empirical formula, is 10.78 g/cm3. The mineral is tetragonal, space group P4/mmm, with a 3.98600(3), c 6.98385(8) Å, V 110.961(2) Å3, and Z = 1. The crystal structure of synthetic Pd5InAs was solved and refined using powder X-ray-diffraction data from synthetic Pd5InAs. Viteite crystallizes with the Pd5TlAs structure type. The strongest lines in the X-ray powder diffraction pattern of synthetic Pd5InAs [d in Å (I) (hkl)] are: 2.3281(45)(003), 2.1932(100)(112), 1.9928(33)(020), 1.2515(17)(115), 1.1857(25)(132). The mineral is named for the Vite river, which flows near the Monchetundra intrusion.

Palladothallite, Pd3Tl, a new mineral from the Monchetundra layered intrusion, Kola Peninsula, Russia

2021 ◽  
Vol 59 (6) ◽  
pp. 1821-1832
Author(s):  
Tatiana L. Grokhovskaya ◽  
Anna Vymazalová ◽  
František Laufek ◽  
Chris J. Stanley ◽  
Sergey Ye. Borisovskiy
Keyword(s):  
Kola Peninsula ◽  
Empirical Formula ◽  
Polarized Light ◽  
Layered Intrusion ◽  
Structure Type ◽  
New Mineral ◽  
Near Surface ◽  
Holotype Specimen ◽  
Powder Neutron Diffraction Data ◽  
The Ideal

ABSTRACT Palladothallite, Pd3Tl, is a new mineral discovered in the Monchetundra layered intrusion, Kola Peninsula, Russia. Palladothallite occurs in orthopyroxenite with disseminated Ni-Cu-Fe sulfides and in near-surface oxidized ore of an orthopyroxenite unit. In the holotype specimen, the new mineral forms anhedral grains about 1 to 20 μm in size intergrown with bortnikovite (Pt4Cu3Zn). Palladothallite and bortnikovite form a rim around tulameenite (Pt2FeCu), Pt-Pd-Fe-Cu alloys, and Pt-Pd-Fe-Cu “oxides” in a goethite matrix. In plane-polarized light, palladothallite is white, anisotropy was not observed; it exhibits no internal reflections. Reflectance values of palladothallite in air (R' in %) are: 53.9 at 470 nm, 57.1 at 546 nm, 59.4 at 589 nm and 61.7 at 650 nm. Twelve electron probe microanalyses of palladothallite gave an average composition (in wt.%): Pd 59.99, Cu 1.19, Fe 0.35, Ag 1.1, Tl 35.64, Se 0.34, and S 0.09, total 99.67, corresponding to the empirical formula (Pd2.894Cu0.096Fe0.032Ag0.053)∑3.075(Tl0.895Se0.023S0.008)∑0.926 based on four atoms, with the ideal formula Pd3Tl. The density, calculated on the basis of the empirical formula, is 13.04 g/cm3. Palladothallite crystallizes with the same structure as synthetic Pd3Tl, which was solved by Kurtzemann & Kohlmann (2010) from powder neutron diffraction data. Palladothallite is tetragonal, space group I4/mmm, with a 4.10659(9), c 15.3028(4) Å, V 258.07(1) Å3, and Z = 4. Palladothallite crystallizes in the ZrAl3 structure type. The name corresponds to its chemical composition, palladium and thallium.

Mitrofanovite, Pt3Te4, a new mineral from the East Chuarvy deposit, Fedorovo–Pana intrusion, Kola Peninsula, Russia

2018 ◽  
Vol 83 (4) ◽  
pp. 523-530 ◽  
Author(s):  
Victor V. Subbotin ◽  
Anna Vymazalová ◽  
František Laufek ◽  
Yevgeny E. Savchenko ◽  
Chris J. Stanley ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Electron Backscatter Diffraction ◽  
New Mineral ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structural Identity ◽  
Polarised Light ◽  
Fe Alloys ◽  
Backscatter Diffraction

AbstractMitrofanovite, Pt3Te4, is a new telluride discovered in low-sulfide disseminated ore in the East Chuarvy deposit, Fedorovo–Pana intrusion, Kola Peninsula, Russia. It forms anhedral grains (up to ~20 μm × 50 μm) commonly in intergrowths with moncheite in aggregates with lukkulaisvaaraite, kotulskite, vysotskite, braggite, keithconnite, rustenburgite and Pt–Fe alloys hosted by a chalcopyrite–pentlandite–pyrrhotite matrix. Associated silicates are: orthopyroxene, augite, olivine, amphiboles and plagioclase. Mitrofanovite is brittle; it has a metallic lustre and a grey streak. Mitrofanovite has a good cleavage, along {001}. In plane-polarised light, mitrofanovite is bright white with medium to strong bireflectance, slight pleochroism, and strong anisotropy on non-basal sections with greyish brown rotation tints; it exhibits no internal reflections. Reflectance values for the synthetic analogue of mitrofanovite in air (Ro, Re’ in %) are: 58.4, 54.6 at 470 nm; 62.7, 58.0 at 546 nm; 63.4, 59.1 at 589 nm; and 63.6, 59.5 at 650 nm. Fifteen electron-microprobe analyses of mitrofanovite gave an average composition: Pt 52.08, Pd 0.19, Te 47.08 and Bi 0.91, total 100.27 wt.%, corresponding to the formula (Pt2.91Pd0.02)Σ2.93(Te4.02Bi0.05)Σ4.07 based on 7 atoms; the average of eleven analyses on synthetic analogue is: Pt 52.57 and Te 47.45, total 100.02 wt.%, corresponding to Pt2.94Te4.06. The density, calculated on the basis of the formula, is 11.18 g/cm3. The mineral is trigonal, space group R$\overline 3 $m, with a = 3.9874(1), c = 35.361(1) Å, V = 486.91(2) Å3 and Z = 3. The crystal structure was solved and refined from the powder X-ray-diffraction data of synthetic Pt3Te4. Mitrofanovite is structurally and chemically related to moncheite (PtTe2). The strongest lines in the powder X-ray diffraction pattern of synthetic mitrofanovite [d in Å (I) (hkl)] are: 11.790(23)(003), 5.891(100)(006), 2.851(26)(107), 2.137(16)(1013), 2.039(18)(0114), 1.574(24)(0120), 1.3098(21)(0027). The structural identity of natural mitrofanovite with synthetic Pt3Te4 was confirmed by electron backscatter diffraction measurements on the natural sample. The mineral name is chosen to honour Felix P. Mitrofanov, a Russian geologist who was among the first to discover platinum-group element mineralisation in the Fedorova–Pana complex.

Nipalarsite, Ni8Pd3As4, a new platinum-group mineral from the Monchetundra Intrusion, Kola Peninsula, Russia

2019 ◽  
Vol 83 (6) ◽  
pp. 837-845 ◽  
Author(s):  
Tatiana L. Grokhovskaya ◽  
Oxana V. Karimova ◽  
Anna Vymazalová ◽  
František Laufek ◽  
Dmitry A. Chareev ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Empirical Formula ◽  
Layered Intrusion ◽  
Mean Value ◽  
Platinum Group Mineral ◽  
X Ray Diffraction ◽  
Wavelength Dispersive Spectroscopy ◽  
Group Mineral ◽  
X Ray ◽  
Platinum Group

AbstractNipalarsite, Ni8Pd3As4, is a new platinum-group mineral discovered in the sulfide-bearing orthopyroxenite of the Monchetundra layered intrusion, Kola Peninsula, Russia (67°52′22″N, 32°47′60″E). Nipalarsite forms anhedral grains (5–80 µm in size) in intergrowths with sperrylite, kotulskite, hollingworthite, isomertieite, menshikovite, palarstanide, nielsenite and monchetundtraite enclosed in pentlandite, anthophyllite, actinolite and chlorite. Nipalarsite is brittle, has a metallic lustre and a grey streak. In plane-polarised light, nipalarsite is light grey with a blue tinge. Reflectance values in air (in %) are: 46.06 at 470 nm, 48.74 at 546 nm, 50.64 at 589 nm and 54.12 at 650 nm. Values of VHN20 fall between 400.5 and 449.2 kg.mm–2, with a mean value of 429.9 kg.mm–2, corresponding to a Mohs hardness of ~4. The average result of 27 electron microprobe wavelength dispersive spectroscopy analyses of nipalarsite is (wt.%): Ni 44.011, Pd 28.74, Fe0.32, Cu 0.85, Pt 0.01, Au 0.05, As 25.42, Sb 0.05, Te 0.39, total 99.85. The empirical formula (normalised to 15 atoms per formula unit) is: (Ni8.10Fe0.06)Σ8.16(Pd2.94Cu0.18)Σ3.12(As3.68Te0.03)Σ3.71 or, ideally, Ni8Pd3As4. Nipalarsite is cubic, space group Fm$\bar{3}$m, with a = 11.4428(9) Å, V = 1498.3(4) Å3 and Z = 8. The strongest lines in the powder X-ray diffraction pattern of synthetic Ni8Pd3As4 [d, Å (I) (hkl)] are: 2.859(10)(004), 2.623(6)(313), 2.557(6)(024), 2.334(11)(224), 2.201(35)(115,333), 2.021(100)(044), 1.906(8)(006,244) and 1.429(7)(008). The crystal structure was solved and refined from the single-crystal X-ray diffraction data of synthetic Ni8Pd3As4. The relation between natural and synthetic nipalarsite is illustrated by an electron back-scattered diffraction study of natural nipalarsite. The density calculated on the basis of the empirical formula of nipalarsite is 9.60 g.cm–3. The mineral name corresponds to the three main elements: Ni, Pd and As.

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.

scholarly journals Thalhammerite, Pd9Ag2Bi2S4, a New Mineral from the Talnakh and Oktyabrsk Deposits, Noril’sk Region, Russia

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 339 ◽  
Author(s):  
Anna Vymazalová ◽  
František Laufek ◽  
Sergey Sluzhenikin ◽  
Vladimir Kozlov ◽  
Chris Stanley ◽  
...  
Keyword(s):  
Empirical Formula ◽  
Polarized Light ◽  
Associate Professor ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Average Composition ◽  
Weak Anisotropy ◽  
X Ray ◽  
Light Yellow ◽  
The University

Thalhammerite, Pd9Ag2Bi2S4, is a new sulphide discovered in galena-pyrite-chalcopyrite and millerite-bornite-chalcopyrite vein-disseminated ores from the Komsomolsky mine of the Talnakh and Oktyabrsk deposits, Noril’sk region, Russia. It forms tiny inclusions (from a few μm up to about 40–50 μm) intergrown in galena, chalcopyrite, and also in bornite. Thalhammerite is brittle and has a metallic lustre. In plane-polarized light, thalhammerite is light yellow with weak bireflectance, weak pleochroism, in shades of slightly yellowish brown and weak anisotropy; it exhibits no internal reflections. Reflectance values of thalhammerite in air (R1, R2 in %) are: 41.9/43.0 at 470 nm, 43.9/45.1 at 546 nm, 44.9/46.1 at 589 nm, and 46.3/47.5 at 650 nm. Three spot analyses of thalhammerite give an average composition: Pd 52.61, Bi 22.21, Pb 3.92, Ag 14.37, S 7.69, and Se 0.10, total 100.90 wt %, corresponding to the empirical formula Pd8.46Ag2.28(Bi1.82Pb0.32)Σ2.14(S4.10Se0.02)Σ4.12 based on 17 atoms; the average of five analyses on synthetic thalhammerite is: Pd 55.10, Bi 24.99, Ag 12.75, and S 7.46, total 100.30 wt %, corresponding to Pd8.91Ag2.03Bi2.06S4.00. The density, calculated on the basis of the empirical formula, is 9.72 g/cm3. The mineral is tetragonal, space group I4/mmm, with a 8.0266(2), c 9.1531(2) Å, V 589.70(2) Å3 and Z = 2. The crystal structure was solved and refined from the single-crystal X-ray-diffraction data of synthetic Pd9Ag2Bi2S4. Thalhammerite has no exact structural analogues known in the mineral system; chemically, it is close to coldwellite (Pd3Ag2S) and kravtsovite (PdAg2S). The strongest lines in the X-ray powder diffraction pattern of synthetic thalhammerite [d in Å (I) (hkl)] are: 3.3428(24)(211), 2.8393(46)(220), 2.5685(21)(301), 2.4122(100)(222), 2.3245(61)(123), 2.2873(48)(004), 2.2201(29)(132), 2.0072(40)(400), 1.7481(23)(332), and 1.5085(30)(404). The mineral honours Associate Professor Oskar Thalhammer of the University of Leoben, Austria.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

scholarly journals Chirvinskyite, (Na,Ca)13(Fe,Mn,□)2(Ti,Nb)2(Zr,Ti)3-(Si2O7)4(OH,O,F)12, a New Mineral with a Modular Wallpaper Structure, from the Khibiny Alkaline Massif (Kola Peninsula, Russia)

Minerals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 219
Author(s):  
Victor Yakovenchuk ◽  
Yakov Pakhomovsky ◽  
Taras Panikorovskii ◽  
Andrey Zolotarev ◽  
Julia Mikhailova ◽  
...  
Keyword(s):  
Kola Peninsula ◽  
Empirical Formula ◽  
Inorganic Compounds ◽  
Structure Type ◽  
New Mineral ◽  
State University ◽  
Mohs Hardness ◽  
Alkaline Massif ◽  
Khibiny Alkaline Massif ◽  
White Streak

Chirvinskyite, (Na,Ca)13(Fe,Mn,□)2(Ti,Nb)2(Zr,Ti)3(Si2O7)4(OH,O,F)12, is a new wöhlerite–related zirconotitano–sorosilicate. It is triclinic, P1, a = 7.0477(5), b = 9.8725(5), c = 12.2204(9) Å, α = 77.995(5), β = 82.057(6), γ = 89.988(5)°, V = 823.35(9) Å3, Z = 1. The mineral was found in albitized alkaline pegmatites in a foyaite of the Mt. Takhtarvumchorr (Khibiny alkaline massif, Kola Peninsula, Russia, N 67°40’, E 33°33’). Chirvinskyite forms sheaf–like and radiated aggregates (up to 6 mm in diameter) of split fibrous crystals hosted by saccharoidal fluorapatite and albite. The mineral is pale cream in color, with a silky luster and a white streak. The cleavage is not recognized. Mohs hardness is 5. Chirvinskyite is biaxial (–), α 1.670(2), β 1.690(2), γ 1.705(2) (589 nm), 2Vcalc = 80.9°. The calculated and measured densities are 3.41 and 3.07(2) g·cm−3, respectively. The empirical formula based on Si = 8 apfu is (Na9.81Ca3.28K0.01)∑13.10(Fe0.72Mn0.69□0.54Mg0.05)∑2.00 (Ti1.81Nb0.19)∑2.00(Zr2.27Ti0.63)∑2.90(Si2O7)4{(OH)5.94O3.09F2.97}∑12.00. Chirvinskyite belongs to a new structure type of minerals and inorganic compounds and is related to the wöhlerite-group minerals. Its modular “wallpaper” structure consists of disilicate groups Si2O7 and three types of “octahedral walls”. The mineral is named in honor of Petr Nikolaevich Chirvinsky (1880–1955), Russian geologist and petrographer, head of the Petrography Department of the Perm’ State University (1943–1953), for his contributions to mineralogy and petrology, including studies of the Khibiny alkaline massif.

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.

Maletoyvayamite, Au3Se4Te6, a new mineral from Maletoyvayam deposit, Kamchatka peninsula, Russia

2020 ◽  
Vol 84 (1) ◽  
pp. 117-123 ◽  
Author(s):  
Nadhezda D. Tolstykh ◽  
Marek Tuhý ◽  
Anna Vymazalová ◽  
Jakub Plášil ◽  
František Laufek ◽  
...  
Keyword(s):  
Kamchatka Peninsula ◽  
Structure Type ◽  
Van Der Waals Interactions ◽  
New Mineral ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
Triclinic Space Group ◽  
Structural Identity ◽  
Polarised Light

AbstractMaletoyvayamite, Au3Se4Te6, is a new mineral discovered in a heavy-mineral concentrate from the Gaching occurrence of the Maletoyvayam deposit, Kamchatka, Russia (60°19′51.87″N, 164°46′25.65″E). It forms anhedral grains (10 to 50 μm in size) and is found in intergrowths with native gold (Au–Ag), Au tellurides (calaverite), unnamed phases (AuSe, Au2TeSe and Au oxide), native tellurium, sulfosalts (tennantite, tetrahedrite, goldfieldite and watanabeite) and supergene tripuhyite. Maletoyvayamite has a good cleavage on {010} and {001}. In plane-polarised light, maletoyvayamite is grey, has strong bireflectance (grey to bluish grey), and strong anisotropy; it exhibits no internal reflections. Reflectance values for maletoyvayamite in air (Rmin,Rmax in %) are: 38.9, 39.1 at 470 nm; 39.3, 39.5 at 546 nm; 39.3, 39.6 at 589 nm; and 39.4, 39.7 at 650 nm. Sixteen electron-microprobe analyses of maletoyvayamite gave an average composition: Au 34.46, Se 16.76, Te 47.23 and S 0.84, total 99.29 wt.%, corresponding to the formula Au2.90(Se3.52S0.44)Σ3.96Te6.14 based on 13 atoms; the average of eleven analyses on synthetic analogue is: Au 34.20, Se 19.68 and Te 45.42, total 99.30 wt.%, corresponding to Au2.90Se4.16Te5.94. The calculated density is 7.98 g/cm3. The mineral is triclinic, space group P1, with a = 8.901(2), b = 9.0451(14), c = 9.265(4) Å, α = 97.66(3), β = 106.70(2), γ = 101.399(14)°, V = 685.9(4) Å3 and Z = 2. The crystal structure of maletoyvayamite represents a unique structure type resembling a molecular structure. There are cube-like [Au6Se8Te12] clusters linked via van der Waals interactions. The structural identity of maletoyvayamite with the synthetic Au3Se4Te6 was confirmed by powder X-ray diffraction and Raman spectroscopy.

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