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Hudson Heights, Canada

Yakovleva O.S.,Moscow State University | Pekov I.V.,Moscow State University | Horvath L.,594 Main Road | Bryzgalov I.A.,Moscow State University | And 2 more authors.
Geology of Ore Deposits | Year: 2010

High-alumina fenites in the Mont Saint-Hilaire alkaline complex, Québec, Canada, form bodies at the contact of peralkaline nepheline syenite. Fenites are subdivided into four types: corundum-spessartine-biotite-feldspar, muscovite-corundum-hercynite-biotite-feldspar, carbonated muscovite-biotite-hercynite-feldspar, and spessartine-hercynite-feldspar. Accessory minerals of the ilmenite-pyrophanite series, columbites, zircon, thorite, pyrrhotite, Fe, Mn, Mg, Ca, Ba, and REE carbonates, uedaite-(Ce), etc. are identified. Three stages are suggested in the formation of these rocks. In mineralogy and geochemistry, the Mont Saint-Hilaire high-alumina fenites are similar to Al-rich fenites replacing xenoliths in the Khibiny alkaline complex, Russia. In both cases, fenites are related to peralkaline rocks and replace high-alumina protoliths: granite at Mont Saint-Hilaire and metapelites in the Khibiny Mountains. These fenites are regarded as a specific type of fenites with rock-forming Mg-depleted hercynite. © 2010 Pleiades Publishing, Ltd. Source

McDonald A.M.,Laurentian University | Back M.E.,Royal Ontario Museum | Gault R.A.,Canadian Museum of Nature | Horvath L.,594 Main Road
Canadian Mineralogist | Year: 2013

Peatite-(Y), Li4Na12( Y,Na,Ca,HREE )12(PO4)12(CO3)4( F,OH)8, and ramikite-(Y), Li4Na12( Y,Ca,HREE )6Zr6(PO4)12(CO3)4O4(OH,F)4, are two new minerals discovered in the core of the Poudrette pegmatite at Mont Saint-Hilaire, Quebec. Epitacticlike, euhedral crystals (pseudocubes) of both minerals range from 0.1 to 1 mm in size (average: 0.2 mm), with ramikite-(Y) forming yellowish-white cores (dominant) and peatite-(Y) occurring as thin (< 50 um) pale pink rims. Crystals of peatite-(Y) exhibit the dominant forms pinacoid {100}, {010}, and {001} and the minor forms rhombic prism {110}, {101}, and {011}, with crystals of ramikite-(Y) showing the possible forms pedion {100}, {001¯}, {010}, {01¯0}, {001}, and {001¯}. The most common associated minerals include albite, rhodochrosite, siderite, chabazite-Na, synchysite-(Ce), and sabinaite. Peatite-(Y) displays a brittle fracture with very good {100}, {010}, and {001} cleavages; ramikite-(Y) has a splintery fracture with possible weak to poor {100}, {010}, and {001} cleavages. Peatite-(Y) has a vitreous luster and ramikite-(Y) has a vitreous to dull luster. Both minerals have a white streak and neither shows any discernible fluorescence under long-, medium-, or short-wave ultraviolet radiation. Both minerals have an approximate Mohs hardness of 3. Peatite-(Y) has a calculated density of 3.62(1) g/cm3 and ramikite-(Y) of 3.60(1) g/cm3. Both minerals have a very low birefringence (∼100), exhibit parallel extinction, and give poor interference figures; the optic sign and measured 2V of both are unknown. Only one refractive index for each could be measured: peatite-(Y), β = 1.601(1) and for ramikite-(Y), β = 1.636 (1). Four analyses of peatite-(Y) gave an average (range) of (wt. %): Li2O 1.96 (calc.), Na2O 12.95 (12.50-13.30), CaO 1.15 (0.98-1.51), Y2O3 37.32 (37.01-37.52), Gd2O3 0.61 (0.54-0.74), Dy2O3 3.08 (2.91-3.44), Ho 2O3 0.67 (b.d.-1.02), Er2O3 2.88 (2.59-3.15), Tm2O3 0.28 (b.d.-0.40), Yb2O3 1.78 (1.67-1.92), ZrO2 0.67 (0.63-0.70), ThO2 0.37 (b.d.-0.56), P2O5 27.29 (27.09-27.64), F 4.35 (4.03-4.62), CO2 5.79 (calc.), H2O 0.31 (calc.), O = F -1.83, total 99.75, corresponding to Li4Na12(Y10.06Na0.72Ca0.62Dy0.50Er0.46Yb0.28Zr0.17Ho0.11Gd0.10Tm0.04Th0.04Tb0.02)Ʃ13.12(PO4)11.70(CO3)4[F6.97(OH)1.03]Ʃ8 and the simplified formula, Li4Na12(Y,Na,Ca,HREE)12 (PO4)12(CO3)4(F,OH)8. For ramikite-(Y), 22 analyses gave an average (range) of (wt. %): Li2O 2.01 (calc.), Na2O 11.25 (10.32-13.34), CaO 4.15 (4.01-4.27), Y2O3 16.48 (14.88-18.25), La2O3 0.11 (b.d.-0.48), Ce2O3 0.10 (b.d.-0.40), Nd2O3 0.08 (b.d.-0.31), Dy2O3 1.11 (0.96-1.23), Er2O3 1.18 (1.01-1.36), Yb2O3 0.57 (0.46-0.68), ZrO2 23.40 (22.66-24.70), ThO2 0.49 (b.d.-0.70), HfO2 0.69 (0.48-0.92), Al2O3 0.14 (0.09- 0.22), P2O5 28.10 (27.47-28.58), F 0.62 (0.24-0.90), CO2 5.92 (calc.), H2O 0.92 (calc.), O = F -0.26, total 97.06, corresponding to Li4 (Na10.79 Ca1.21) Ʃ12(Y4.34 Ca0.99 Dy0.18 Er0.18 Yb0.09 La 0.02 Ce0.02 Nd0.01)Ʃ 5.83(Zr5.65 Hf0.10 Th0.06 )Ʃ 5.81[( P0.98 Al0.01 )Ʃ0.99 O4]12(CO3)4O4[(OH)3.03F0.97]Ʃ4.00 and the simplified formula, Li4(Na,Ca)12 (Y,Ca,HREE)6 Zr6(PO4)12(CO3)4O4(OH,F)4. In both peatite-(Y) and ramikite-(Y), the presence of Li2O was confirmed via crystal-structure and LAM-ICP-MS analyses and both H2O and CO2 via results of crystal-structure, infrared, and Raman analyses. Peatite-(Y) crystallizes in space group P222 with a 11.167(2), b 11.164(2), c 11.162(2) Å, V 1391.7(1) Å3, and Z = 1, and ramikite-(Y) in space group P1 with a 10.9977(6), b 10.9985(6), c 10.9966(6) Å, α 90.075(4), β 89.984(4), γ 89.969(4)°, V 1330.1(1) Å3, and Z = 1. The strongest six lines on the X-ray powder-diffraction pattern [d in Å (I) (hkl)] for peatite-(Y) are: 4.56(57)(211,121,112), 3.95(57)(220,202,022), 3.54(46) (310,301,130), 2.99(83)(321,312,231), 2.63(100)(330,303,033), 2.149(42)(333) and for ramikite-(Y): 11.04(76)(01¯0,100,001¯), 7.80(79)(01¯1,110,101), 6.36(75)(111¯,11¯1,111,111¯), 3.89(100)(02¯2,220,202), 2.94(98)(132¯,123¯,231¯), 2.59(98)(03¯3,330,303). The crystal structure of peatite-(Y) was refined to R = 3.37% and wR2 = 9.36% for 3816 reflections and that of ramikite-(Y) to R = 5.13% and wR2 = 13.06% for 8272 reflections. While not strictly isostructural, both minerals have similar crystal structures dominated by MOφ8 polyhedra (M = Y,Zr; φ = unspecified ligand). These are linked into six-membered, edge- or corner-sharing clusters, which in turn are joined together by PO4 tetrahedra. Both LiO6 octahedra and CO3 groups are positioned within the corner-sharing clusters. Linkages among all these polyhedra produce an open, equidimensional framework structure, with Na occupying the resulting cavities. Although possessing complex crystal structures, both minerals may be considered more simply as homeotypes of body-centered cubic Fe (or CsCl) or, alternatively, as complex derivatives of cation-deficient perovskite-related structures. Both minerals are late-stage products, possibly related to the in situ alteration of the pre-existing mineral assemblage (dawsonite, burbankite-group minerals, sabinaite, muscovite-polylithionite, etc.) present in the core of the Poudrette pegmatite. Source

Rowe R.,Canadian Museum of Nature | Grice J.D.,Canadian Museum of Nature | Poirier G.,Canadian Museum of Nature | Stanley C.J.,Natural History Museum in London | Horvath L.,594 Main Road
Canadian Mineralogist | Year: 2011

Nisnite, ideally Ni 3Sn, was found during a re-examination of heazlewoodite crystals in rodingite samples from the Jeffrey mine, Asbestos, Quebec. It occurs as bronze-colored metallic, striated, blocky and square to rectangular tabular crystals of up to 100 μm in length, with groupings of <1 mm growing on heazlewoodite. Crystal groupings exhibit a boxwork-like habit. Reflectance measurements in air gave 43.2 (470 nm), 49.1 (546 nm), 53.2 (589 nm), and 59.0% (650 nm). Minerals closely associated with nisnite are chromite, diopside, grossular, heazlewoodite and shandite. The mineral is cubic, P4/m32/m, with unit-cell parameter refined using powder-diffraction data: a 3.7349(6) Å, V 52.10(3) Å 3, Z= 1, D calc = 9.41 g/cm 3. The average results of five and three electron-microprobe analyses on separate crystals gave Ni 57.88, Sn 40.17, sum 98.05 wt.% and Ni 59.24, Sn 41.00, sum 100.24 wt.%, corresponding to Ni 2.98Sn 1.02 on the basis of 4 apfu. The structure has been refined to an R index of 0.008% on the basis of 30 unique reflections. The structure of nisnite contains 12-coordinated Sn atoms (12 Ni) and 12-coordinated Ni atoms (8 Ni and 4 Sn). Among the three synthetic Ni 3Sn phases known, nisnite corresponds to the ccp structure that has been synthesized at high pressure and high temperature. Source

Horvath L.,594 Main Road | Pfenninger-Horvath E.,594 Main Road | Spertini F.,212 rue Hutcheson
Mineralogical Record | Year: 2013

The Jeffrey mine, once the largest producer of chrysotile asbestos in the world, was in continuous operation for almost 130 years until its recent decline and closure. It is the most famous and by far the most prolific specimen-producing, classic mineral locality in Canada, best known to collectors for the superb specimens of grossular and vesuvianite. It is also well known for outstanding crystallized specimens of prehnite, pectolite and diopside, and is the type locality for spertiniite, jeffreyite and nisnite. Source

Pekov I.V.,Moscow State University | Chukanov N.V.,RAS Institute of Problems of Chemical Physics | Zubkova N.V.,Moscow State University | Ksenofontov D.A.,Moscow State University | And 3 more authors.
Canadian Mineralogist | Year: 2010

Lecoqite-(Y), ideally Na3Y(CO3)3· 6H2O, a new mineral species, was discovered at the Poudrette quarry, Mont Saint-Hilaire, Quebec, Canada. It is associated with microcline, albite, natrolite, gonnardite, aegirine, siderite, elpidite, gaidonnayite, zircon, franconite, dawsonite, rhodochrosite, cryolite, rutile, and sphalerite. Lecoqite-(Y) forms radiating, spray-like aggregates in compact, tightly packed masses to 2.5 cm across, composed of flexible, extremely thin, capillary crystals up to 2.5 cm long and up to 0.01 mm thick. Individuals are colorless, and aggregates are white. The luster is strikingly silky. D(calc.) = 2.358 g/cm3. Lecoqite-(Y) is optically uniaxial positive, ω = 1.521(3),□ = 1.497(3). The IR spectrum is unique. The chemical composition (electron microprobe, H2O by modified Penfield method, CO2 by selective absorption, average results) is: Na2O 19.22, CaO 0.03, Y2O3 17.95, Nd2O3 0.54, Sm 2O3 0.41, Gd2O3 0.75, Dy 2O3 3.31, Ho2O3 1.12, Er 2O3 3.20, Yb2O3 1.48, CO2 27.0, H2O 23.4, total 98.41 wt.%. The empirical formula calculated for 15 O apfu is: Na2.94(Y0.755Dy0.085Er 0.08Yb0.035Ho0.03Gd0. 02Nd 0.015 Sm0.01)Σ1.03(CO3) 2.91(OH)0.21(H2O)6.06. Lecoqite-(Y) is hexagonal, P63, a 11.316(4), c 5.931(2) Å, V 657.7(4) Å3, Z = 2. The crystal structure was established from X-ray powder data by the Rietveld method, based on the model of the isostructural synthetic Ln-free carbonate Na3Y(CO3)3· 6H2O. Final agreement factors are: Rp = 0.0468, R wp., = 0.0657, RBragg = 0.0343, RF = 0.0356. No mineral is closely related to lecoqite-(Y) in terms of structure. In the structure of lecoqite-(Y), REE atoms (REE = Y + Ln) are surrounded by six O atoms of CO3 groups and three H2O molecules to form a tricapped triangular prism. The Na atoms are centered in distorted octahedra [NaO4(H2O)2], which link to form infinite corrugated chains along c. The strongest five lines of the X-ray powder pattern [d in Å (I)(hkl)] are: 9.82(57)(100), 5.081 (100)(101), 3.779(39)(201), 2.627(39)(112), 2.471 (37)(131). Lecoqite-(Y) is named in memory of P.É. Lecoq de Boisbaudran (1838-1912), outstanding French chemist and specialist in the spectroscopic analysis of minerals and synthetic compounds, who made a great contribution to the chemistry of the rare-earth elements. The Levinson suffix modifier -(Y) is in line with the dominance of yttrium over other rare-earth elements in the mineral. The cotype specimens are deposited in the Fersman Mineralogical Museum of Russian Academy of Sciences, Moscow, and the Canadian Museum of Nature, Ottawa. Source

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