scholarly journals Sazhinite-(La), Na3LaSi6O15(H2O)2, a new mineral from the Aris phonolite, Namibia: Description and crystal structure

2006 ◽  
Vol 70 (4) ◽  
pp. 405-418 ◽  
Author(s):  
F. Cámara ◽  
L. Ottolini ◽  
B. Devouard ◽  
L. A. J. Garvie ◽  
F. C. Hawthorne
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Polarized Light ◽  
Total Content ◽  
New Mineral ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Average Composition ◽  
Mohs Hardness ◽  
Silicate Layers ◽  
Secondary Ion

AbstractSazhinite-(La) is a new mineral from the Aris phonolite, Windhoek, Namibia. It occurs in vesicles within the phonolite, together with other species crystallized from late-stage hydrothermal fluids: natrolite, aegirine, microcline, apophyllite, sphalerite, analcime, fluorite, villiaumite, hydroxylapatite, galena, makatite, quartz, eudialyte, kanemite, tuperssuatsiaite and korobitsynite. Sazhinite-(La) forms small euhedral crystals up to 1 mm long and 0.4 mm wide, elongated along [001] and flattened on (010), exhibiting the forms {h0l}, {100} and {001}. It has good cleavage parallel to {010} and {001}. Twinning was not observed. Crystals are brittle with a Mohs hardness of 3, creamy white with a white streak, vitreous to pearly lustre, and translucent to transparent. In plane-polarized light, crystals are colourless with a = Z, b = Y, c = X. It is biaxial positive with α = 1.524, β = 1.528, γ = 1.544, all ±0.002, 2Vz(obs) = 46(1)°, and 2Vz(calc.) = 53.6°.Sazhmite-(La) is orthorhombic Pmm2, a = 7.415(2), b = 15.515(3), c = 7.164(1) Å, and V = 824.2 Å3. One crystal was studied by X-ray diffraction, electron microprobe and secondary ion mass spectrometry (SIMS) microanalysis, leading to the average composition (Na2.87K0.02Sr0.01)Σ2.90 [La0.41Ce0.35Pr0.02Nd0.04(Sm,Gd,Dy,Er,Yb)Σ0.01Th0.09U0.01Y0.01Zr0.01Ca0.08Li0.01]Σ1.04 (S15.87S0.06B0.01) (O14.86F0.14).(H2O)2.Weighted full-matrix least-squares refinement on 3369 reflections yielded Rall = 3.8%. The structure is built of corrugated [Si6O15]6- layers linked by [7]-coordinated REE and R4+ cations. This framework leaves channels that contain three [5]- and [6]-coordinated Na cations per formula unit that compensate for the residual charge on the silicate layers. The SIMS analyses confirm a Na content of 3 atoms per formula unit, leading to an ideal formula of Na3LaSi6O15(H2O)2. The third Na atom is bonded to H2O groups and therefore the total content of both Na and H2O may be reduced to 2 and 1 per formula, respectively. The depletion in Na allows for the entrance of high-charge cations such as Th4+.

Lukkulaisvaaraite, Pd14Ag2Te9, a new mineral from Lukkulaisvaara intrusion, northern Russian Karelia, Russia

2014 ◽  
Vol 78 (7) ◽  
pp. 1743-1754 ◽  
Author(s):  
A. Vymazalová ◽  
T. L. Grokhovskaya ◽  
F. Laufek ◽  
V. A. Rassulov
Keyword(s):  
Polarized Light ◽  
Structure Type ◽  
Mean Value ◽  
New Mineral ◽  
Polished Section ◽  
X Ray Diffraction ◽  
Average Composition ◽  
Xrd Pattern ◽  
Mohs Hardness ◽  
Russian Karelia

AbstractLukkulaisvaaraite, Pd14Ag2Te9, is a new platinum-group mineral discovered in the Lukkulaisvaara intrusion, northern Russian Karelia, Russia. In polished section crystals are ~40 mm across, rimmed by tulameenite and accompanied to varying degrees by telargpalite and Bi-rich kotulskite. Lukkulaisvaaraite is brittle, has a metallic lustre and a grey streak. Values of VHN20 fall between 339 and 371 kg mm–2, with a mean value of 355 kg mm–2, corresponding to a Mohs hardness of ~4. In plane-polarized light, lukkulaisvaaraite is light grey with a brownish tinge, has strong bireflectance, light brownish-grey to greyish-brown pleochroism and distinct to strong anisotropy; it exhibits no internal reflections. Reflectance values of lukkulaisvaaraite in air (R1, R2, in %) are: 40.9, 48.3 at 470 nm, 47.6, 56.4 at 546 nm, 52.1, 61.0 at 589 nm and 57.5, 65.2 at 650 nm. Five electron microprobe analyses of natural lukkulaisvaaraite gave the average composition Pd 52.17, Ag 7.03 and Te 40.36, total 99.61 wt.%, corresponding to the empirical formula Pd14.05Ag1.88Te9.06 based on 25 atoms; the average of nine analyses on synthetic lukkulaisvaaraite is Pd 52.13, Ag 7.31 and Te 40.58, total 100.02 wt.%, corresponding to Pd13.99Ag1.93Te9.08. The mineral is tetragonal, space group I4/m, with a = 8.9599(6), c = 11.822(1) Å , V = 949.1(1) Å3 and Z = 2. The crystal structure was solved and refined from the powder X-ray diffraction (XRD) data of synthetic Pd14Ag2Te9. Lukkulaisvaaraite has a unique structure type and shows similarities to that of sopcheite (Ag4Pd3Te4) and palladseite (Pd17Se15). The strongest lines in the powder XRD pattern of synthetic lukkulaisvaaraite [d(Å),I,hkl] are: 2.8323(58)(130,310), 2.8088(92),(213), 2.5542(66)(312), 2.4312(41)(321,231), 2.1367(57)(411,141), 2.1015(52)(233,323), 2.0449(100)(314), 2.0031(63)(420,240), 1.9700(30)(006), 1.4049(30)(246,426), 1.3187(36)(543,453). The mineral is named for the type locality, the Lukkulaisvaara intrusion in Russian Karelia.

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.

Byrudite, (Be,〈)(V3+,Ti)3O6, a new mineral from the Byrud emerald mine, South Norway

2015 ◽  
Vol 79 (2) ◽  
pp. 261-268 ◽  
Author(s):  
G. Raade ◽  
T. Balić-Žunić ◽  
C. J. Stanley
Keyword(s):  
Empirical Formula ◽  
Secondary Ion Mass Spectrometry ◽  
Inverse Correlation ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Mohs Hardness ◽  
Ore Mineralogy ◽  
Secondary Ion ◽  
Reflectance Data ◽  
Strong Inverse Correlation

AbstractByrudite (IMA 2013-045, Raade et al., 2013), with simplified formula (Be,〈)(V3+,Ti)3O6, occurs in emerald-bearing syenitic pegmatites of Permian age at Byrud farm, Eidsvoll, Akershus, South Norway. It has a norbergite-type structure, Pnma, with a = 9.982(1), b = 8.502(1), c = 4.5480(6) Å, V = 385.97(9) Å3, Z = 4. The structure was refined to R1 = 0.045 for 1413 unique reflections. Twinning occurs on {210}. The occupancy of the tetrahedral Be site refined to 0.84(1). The presence of Be was verified by secondary ion mass spectrometry but could not be quantified. Electron-microprobe analyses of the crystal used for structure determination gave the empirical formula (Be0.84〈0.16) (V1.323+Ti1.25Cr0.29Fe0.09Al0.07)Σ3.02O6. There is a strong inverse correlation between V and Cr. The ideal endmember formula is BeV23+TiO6. The mineral is black and opaque with a metallic lustre. Reflectance data in air are reported from 400 to 700 nm. The Commission on Ore Mineralogy required wavelengths are [R1, R2(λ in nm)]:16.6,17.5(470), 16.7,17.9(546), 16.8,18.3(589) and 16.8,18.6(650). The Mohs hardness is ∼7, based on indentation measurements. The mineral is brittle with an uneven fracture; cleavage is not present. D(calc.) = 4.35 g cm–3 for the empirical formula with 0.84 Be a.p.f.u. The strongest reflections of the calculated powder X-ray diffraction pattern are [d in Å (Irel)(hkl)]: 3.721(72)(111), 2.965(100)(121), 2.561(50)(311), 2.464(41)(230), 2.167(24)(231), 1.681(34)(402), 1.671(66)(232), 1.435(23)(630).

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.

Fluoro-potassic-pargasite, KCa2(Mg4Al)(Si6Al2)O22F2, from the Tranomaro area, Madagascar: mineral description and crystal chemistry

2010 ◽  
Vol 74 (6) ◽  
pp. 961-967 ◽  
Author(s):  
R. Oberti ◽  
M. Boiocchi ◽  
F. C. Hawthorne ◽  
R. Pagano ◽  
A. Pagano
Keyword(s):  
Polarized Light ◽  
Mineral Species ◽  
New Mineral ◽  
Monoclinic Space Group ◽  
Formula Unit ◽  
X Ray ◽  
New Mineral Species ◽  
Mohs Hardness ◽  
Brownish Black ◽  
Amphibole Crystal

AbstractFluoro-potassic-pargasite, ideally AKBCa2C(Mg4Al) (Si6Al2)O22WF2, a new amphibole species, has been found in a skarn in the Tranomaro area, Madgascar. The sample used for the description of the new mineral species is a large single amphibole crystal, 4 mm × 2 mm × 2 cm in size, brownish-black with brownish-yellow phlogopite lamellae adhering to one face of the crystal. Fluoro-potassic-pargasite is brittle, has a Mohs hardness of 6.5 and a splintery fracture; it is non-fluorescent, has perfect {110} cleavage, no observable parting, and has measured and calculated densities of 3.46 and 3.151 g cm−3, respectively. In plane-polarized light, it is pleochroic, X = colourless to very pale grey, Y = very pale grey, Z = colourless; X ^ a = 46.9° (in β obtuse), Y ‖ b, Z ^ c = 31.4° (in β acute). It is biaxial positive, α = 1.638(2), β = 1.641(2), γ = 1.653(2); 2Vobs = 49.6(4)°, 2Vcalc = 53.4°.Fluoro-potassic-pargasite is monoclinic, space group C2/m, a = 9.9104(2), b = 17.9739(4), c = 5.3205(1) Å, β = 105.534(2)°, V = 913.11(6) Å3, Z = 2. The eight strongest lines in the X-ray powder-diffraction pattern are [d in Å(I)(hkl)]: 3.133(100)(310), 3.270(55)(240), 2.809(47)(330). 8.413(45)(110), 2.698(39)(151), 3.374(31)(131), 2.934(29)(221) and 1.647(29)(461). Electron microp-robe analysis gives SiO2 40.20, Al2O3 17.61, TiO2 0.46, FeO 1.96, Fe2O3 2.51, MgO 16.95, MnO 0.05, CaO 13.18, Na2O 0.99, K2O 3.72, F 2.75, H2Ocalc 0.77, sum 99.99 wt.%. The formula unit, calculated on the basis of 24 (O,OH,F) with (OH + F) = 2 - (2 × Ti), is A(K0.69Na0.28Ca0.04)∑=1.01BCa2.00C(Mg3.64Fe0.242+Mn0.01Al0.79Fe0.273+Ti0.05)∑=5.00T(Si5.80Al2.20)∑=8.00O22W[F1.26(OH)0.74]∑=2.00. The mineral species and name have been approved by the IMA CMNMC (IMA 2009-091).

Yarzhemskiite, K[B5O7(OH)2]⋅H2O, a new mineral from the Chelkar salt dome, Western Kazakhstan

2019 ◽  
Vol 84 (2) ◽  
pp. 335-342
Author(s):  
Igor V. Pekov ◽  
Natalia V. Zubkova ◽  
Oksana V. Korotchenkova ◽  
Ilya I. Chaikovskiy ◽  
Vasiliy O. Yapaskurt ◽  
...  
Keyword(s):  
Structural Unit ◽  
Salt Dome ◽  
New Mineral ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Double Ring ◽  
Western Kazakhstan ◽  
Mohs Hardness

AbstractThe new mineral yarzhemskiite, K[B5O7(OH)2]⋅H2O, was found in a halite–sylvite evaporite rock at the Chelkar salt dome, Western Kazakhstan Region, Kazakhstan. It is also associated with carnallite, polyhalite, gypsum, strontioginorite, satimolite and quartz. Yarzhemskiite occurs as separate thick tabular, short prismatic or equant crystals up to 0.5 mm × 0.7 mm × 1 mm and grains having irregular outlines up to 1 mm × 1.5 mm × 2 mm. The mineral is transparent, colourless, with vitreous lustre. It is brittle, the Mohs’ hardness is ca 2½. Cleavage is perfect on {100}. Dmeas is 2.13(1) and Dcalc is 2.112 g cm–3. Yarzhemskiite is optically biaxial (+), α = 1.484(2), β = 1.508(2), γ = 1.546(2), 2Vmeas = 75(10)° and 2Vcalc = 80°. Chemical composition (wt.%, electron microprobe, H2O was calculated by stoichiometry) is: Na2O 0.01, K2O 17.84, CaO 0.07, B2O3 67.21, H2Ocalc 13.91, total 99.04. The empirical formula based on 10 O atoms per formula unit is K0.98B5.005O7(OH)2⋅H2O. Yarzhemskiite is monoclinic, P21/c, a = 9.47340(18), b = 7.52030(16), c = 11.4205(2) Å, β = 97.3002(17)°, V = 807.03(3) Å3 and Z = 4. The strongest reflections of the powder XRD pattern [d,Å(I,%)(hkl)] are: 9.39(86)(100), 4.696(41)(200), 3.296(18)($\bar{1}$13), 3.130(19)(022, 300), 2.935(42)(220), 2.898(100)($\bar{3}$02, $\bar{2}$21, 310), 2.832(56)(004) and 1.867(18)($\bar{2}$25). The crystal structure was solved based on single-crystal X-ray diffraction data, R1 = 3.36%. The structure contains infinite chains built by boron-centred polyhedra. The basic structural unit of the chain is a double ring B5O7(OH)2 consisting of one BO4 tetrahedron and four BO3 triangles. K+ cations centre ten-fold polyhedra which form, together with the borate chains [B5O7(OH)2]–∝, layers linked with each other only via H bonds. The mineral is named in honour of the Russian geologist, petrologist and mineralogist Yakov Yakovlevich Yarzhemskii (1901–?), a specialist in petrology of evaporite rocks and mineralogy and genesis of boron deposits related to evaporites.

Antofagastaite, Na2Ca(SO4)2·1.5H2O, a new mineral related to syngenite

2019 ◽  
Vol 83 (6) ◽  
pp. 781-790
Author(s):  
Igor V. Pekov ◽  
Vadim M. Kovrugin ◽  
Oleg I. Siidra ◽  
Nikita V. Chukanov ◽  
Dmitry I. Belakovskiy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
New Mineral ◽  
Formula Unit ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Quartz Veins ◽  
Tolbachik Volcano ◽  
Mohs Hardness ◽  
The One

AbstractThe new mineral antofagastaite, ideally Na2Ca(SO4)2·1.5H2O, was found in the oxidation zone of sulfide–quartz veins at the abandoned Coronel Manuel Rodríguez mine, Mejillones, Antofagasta Province, Antofagasta Region, Chile. It is associated with sideronatrite, metasideronatrite, aubertite, gypsum, ferrinatrite, glauberite, amarillite and an unidentified Fe phosphate. Antofagastaite occurs as prismatic crystals up to 0.5 mm × 1 mm × 5 mm, elongated along [010], typically combined in open-work aggregates up to 1 cm across. Antofagastaite is transparent and colourless, with vitreous lustre. It is brittle; the Mohs’ hardness isca3. Cleavage is distinct on (001).Dmeas.is 2.42(1) andDcalc.is 2.465 g cm−3. Antofagastaite is optically biaxial (–), α = 1.489(2), β = 1.508(2), γ = 1.510(2) and 2Vmeas.= 40(10)°. The IR spectrum is reported. Chemical composition (wt.%, electron microprobe, H2O determined by gas chromatography) is: Na2O 20.85, CaO 17.42, SO352.56, H2O 7.93, total 98.76. The empirical formula (based on 8 O atoms belonging to sulfate anions per formula unit with all H belonging to H2O molecules) is Na2.06Ca0.95S2.01O8·1.35H2O. Antofagastaite is monoclinic,P21/m,a= 6.4596(4),b= 6.8703(5),c= 9.4685(7) Å, β = 104.580(4)°,V= 406.67(5) Å3andZ= 2. The strongest reflections of the powder XRD pattern [d, Å (I, %) (hkl)] are: 9.17 (100) (001), 5.501 (57) (011), 3.437 (59) (020), 3.058 (43) (003), 2.918 (50) (2¯11), 2.795 (35) (013) and 2.753 (50) (121, 201). The crystal structure was solved based on single-crystal X-ray diffraction data,R1= 5.71%. The structure of antofagastaite consists of ordered and disordered blocks and is related to syngenite K2Ca(SO4)2·H2O. Incorporation of additional H2O molecules in the syngenite-type structure results in disorder of the one of the two tetrahedral sulfate groups occurring in antofagastaite. In addition to the above-reported type material, antofagastaite together with syngenite and blödite occurs in the Arsenatnaya fumarole, Tolbachik volcano, Kamchatka, 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.

Hingganite-(Nd), Nd2□Be2Si2O8(OH)2, a new gadolinite-supergroup mineral from Zagi Mountain, Pakistan

2020 ◽  
Vol 58 (5) ◽  
pp. 549-562
Author(s):  
Anatoly V. Kasatkin ◽  
Fabrizio Nestola ◽  
Radek Škoda ◽  
Nikita V. Chukanov ◽  
Atali A. Agakhanov ◽  
...  
Keyword(s):  
New Mineral ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Average Chemical Composition ◽  
X Ray ◽  
Conchoidal Fracture ◽  
Icp Ms ◽  
Optical Axes ◽  
Mohs Hardness ◽  
Khyber Pakhtunkhwa Province

ABSTRACT Hingganite-(Nd), ideally Nd2□Be2Si2O8(OH)2, is a new gadolinite group, gadolinite supergroup mineral discovered at Zagi Mountain, near Kafoor Dheri, about 4 km S of Warsak and 30 km NW of Peshawar, Khyber Pakhtunkhwa Province, Pakistan. The new mineral forms zones measuring up to 1 × 1 mm2 in loose prismatic crystals up to 0.7 cm long, where it is intergrown with hingganite-(Y). Other associated minerals include aegirine, microcline, fergusonite-(Y), and zircon. Hingganite-(Nd) is dark greenish-brown, transparent, has vitreous luster and a white streak. It is brittle and has a conchoidal fracture. No cleavage or parting are observed. Mohs hardness is 5½–6. Dcalc. = 4.690 g/cm3. Hingganite-(Nd) is non-pleochroic, optically biaxial (+), α = 1.746(5), β = 1.766(5), γ = 1.792(6) (589 nm). 2Vmeas. = 80(7)°; 2Vcalc. = 84°. Dispersion of optical axes was not observed. The average chemical composition of hingganite-(Nd) is as follows (wt.%; electron microprobe, BeO, B2O3, and Lu2O3 content measured by LA-ICP-MS; H2O calculated by stoichiometry): BeO 9.64, CaO 0.45, MnO 0.10, FeO 3.03, B2O3 0.42, Y2O3 8.75, La2O3 1.63, Ce2O3 12.89, Pr2O3 3.09, Nd2O3 16.90, Sm2O3 5.97, Eu2O3 1.08, Gd2O3 5.15, Tb2O3 0.50, Dy2O3 2.50, Ho2O3 0.33, Er2O3 0.84, Tm2O3 0.10, Yb2O3 0.44, Lu2O3 0.04, ThO2 0.13, SiO2 23.55, H2O 2.72, total 100.25. The empirical formula calculated on the basis of 2 Si apfu is (Nd0.513Ce0.401Y0.395Sm0.175Gd0.145Pr0.096Dy0.068La0.051Ca0.041Eu0.031Er0.022Tb0.014Yb0.011Ho0.009Tm0.003Th0.003Lu0.001)Σ1.979(□0.778Fe2+0.215Mn0.007)Σ1.000(Be1.967B0.062)Σ2.029Si2O8.46(OH)1.54. Hingganite-(Nd) is monoclinic, space group P21/c with a = 4.77193(15), b = 7.6422(2), c = 9.9299(2) Å, β = 89.851(2)°, V = 362.123(14) Å3, and Z = 2. The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 6.105 (95) (011), 4.959 (56) (002), 4.773 (100) (100), 3.462 (58) (102), 3.122 , 3.028 (61) (013), 2.864 (87) (121), 2.573 (89) (113). The crystal structure of hingganite-(Nd) was refined from single-crystal X-ray diffraction data to R = 0.034 for 2007 unique reflections with I > 2σ(I). The new mineral is named as an analogue of hingganite-(Y), hingganite-(Yb), and hingganite-(Ce), but with Nd dominant among the rare earth elements.

Vymazalováite, Pd3Bi2S2, a new mineral from the Noril'sk-Talnakh deposit, Krasnoyarskiy region, Russia

2018 ◽  
Vol 82 (2) ◽  
pp. 367-373 ◽  
Author(s):  
Sergei F. Sluzhenikin ◽  
Vladimir V. Kozlov ◽  
Chris J. Stanley ◽  
Maria L. Lukashova ◽  
Keith Dicks
Keyword(s):  
Empirical Formula ◽  
Electron Back Scatter Diffraction ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Average Composition ◽  
Reflected Light ◽  
Structural Identity ◽  
Cell Dimensions ◽  
Average Reflectance ◽  
Talnakh Deposit

ABSTRACTVymazalováite, Pd3Bi2S2 is a new platinum-group mineral discovered in the Komsomolsky mine of the Talnakh deposit, Noril'sk district, Russia. It forms small (from a few μm to 20–35 µm) inclusions or euhedral grains in intergrowths of polarite, sobolevskite, acanthite and unnamed (Pd,Ag)5BiS2 in aggregates (up to ~200 µm) in galena and rarely in chalcopyrite. It occurs with telargpalite, cooperite, braggite, vysotskite, sopcheite, stibiopalladinite, sobolevskite, moncheite, kotulskite, malyshevite, insizwaite, Au-bearing silver and the newly described mineral kravtsovite (PdAg2S) in association with pyrite, chalcopyrite and galena in vein-disseminated mineralization in skarn rocks. Synthetic vymazalováite is brittle; it has a metallic lustre and a grey streak. In plane-polarized reflected light, vymazalováite is creamy grey and appears slightly brownish against galena in the assemblage with chalcopyrite. It exhibits no internal reflections. Average reflectance values in air for natural and synthetic vymazalováite are (R natural, R synthetic in %) are: 46.35, 45.7 at 470 nm, 47.65, 47.45 at 546 nm, 48.5, 48.2 at 589 nm and 49.5, 49.0 at 650 nm. Seven electron probe micro-analyses of vymazalováite give an average composition: Pd 40.42, Bi 49.15, Ag 0.55, Pb 1.02, S 7.77 and Se 0.26, total 99.17 wt.%, corresponding to the empirical formula Pd3.05(Bi1.89Ag0.04Pb0.04)Σ1.97(S1.95Se0.03)Σ1.98 based on a total of 7 atoms per formula unit. The simplified formula is Pd3Bi2S2. The mineral is cubic, space group I213, with a = 8.3097(9) Å, V = 573.79(1) Å3 and Z = 4. The density calculated on the basis of the empirical formula and cell dimensions of synthetic vymazalováite is 9.25 g/cm3. The strongest lines in the powder X-ray diffraction pattern of synthetic vymazalováite [d in Å (I) (hkl)] are: 4.15(32)(200), 2.93(78)(220), 2.40(100)(220), 2.08(53)(400), 1.695(34)(422), 1.468(35)(440) and 1.252(31)(622). The structural identity of natural vymazalováite with synthetic Pd3Bi2S2 was confirmed by electron back-scatter diffraction measurements on the natural sample. This new mineral honours Dr Anna Vymazalová of the Czech Geological Survey, Prague.

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