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Tumchaite Na2(Zr,Sn)Si4O11·2H2O—A new mineral from carbonatites of the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia

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Published/Copyright: March 25, 2015
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American Mineralogist
From the journal American Mineralogist Volume 85 Issue 10

Abstract

Tumchaite, Na2(Zr,Sn)Si4O11·2H2O, is a new species from the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia, where it occurs as colorless to white tabular monoclinic crystals associated with calcite, dolomite, a mineral of the serpentine group and pyrite in the late dolomitecalcite carbonatites. It is transparent to translucent; with vitreous luster; and perfect cleavage on (100). Mohs hardness is 4.5, Dmeas is 2.78 (2) g/cm3. Tumchaite is optically biaxial (-), with α = 1.570 (2), β = 1.588 (2), γ = 1.594 (2), 2Vmeas = 60 (5)°, and elongation positive, Y = b, c ∧ Z = 3°. Pleochroism exists, with Y = Z = colorless, X = greenish-gray. Electron microprobe analysis gave (wt%): Na2O 13.72, CaO 0.15, SiO2 52.71, TiO2 0.35, ZrO2 20.41, SnO2 5.73, HfO2 0.60, H2O (computed assuming 2H2O pfu.) 7.86, total 101.53. The X-ray study pointed to space group P21/c, a = 9.144 (4), b = 8.818 (3), c = 7.537 (3) Å, β = 113.22 (3)°, V = 558.49 Å3, Z = 2. The strongest lines of the powder diffraction pattern [d in Å (I) (hkl)] are: 8.40 (10) (100), 5.38 (9) (111̅), 4.00 (8) (111), 3.401 (9) (202̅), 2.902 (9) (211), 2.691 (9) (131̅). The crystal structure of tumchaite was refined to R = 0.043 for 865 Fo > 4σ(Fo). The mineral is isotypic with penkvilksite-1M. The structure is characterized by silicate sheets parallel (100), formed by alternating clockwise- and counterclockwise-growing spiral chains of corner-sharing SiO4 tetrahedra. The sheets are connected by octahedra occupied by (Zr, Sn) at 0, 1/2, 0. The Zr/Sn ratio in the octahedra is 4. Water molecules and Na cations are placed in the cavities of the polyhedral framework. The ideal crystal-chemical formula is Na2 (Zr0.8Sn0.2)[Si4O11]·2H2O. The mineral is named tumchaite for the river Tumcha near Vuoriyarvi massif.

Received: 2000-2-7
Accepted: 2000-5-18
Published Online: 2015-3-25
Published in Print: 2000-10-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite
  2. Viscosities of granitic (sensu lato) melts: Influence of the anorthite component
  3. Geochemistry of pyroxene inclusions from the Warrumbungle Volcano, New South Wales, Australia
  4. Supersilicic clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav massif, Kazakhstan
  5. Experimental study of intracrystalline Fe2+-Mg exchange in three augite crystals: Effect of composition on geothermometric calibration
  6. Transmission electron microscopy and differential thermal studies of lazurite polymorphs
  7. Re-equilibration of glass and CO2 inclusions in xenolith olivine: A TEM study
  8. Origin and structural character of haüyness in spinel dunite xenoliths from La Palma, Canary Islands
  9. Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project
  10. Mineralogy and magnetic behavior of pyrrhotite from a 260 °C section at the KTB drilling site, Germany
  11. Surface defects and self-diffusion on pyrite {100}: An ultra-high vacuum scanning tunneling microscopy and theoretical modeling study
  12. Rare-earth elements in chlorapatite [Ca10(PO4)6Cl2]: Uptake, site preference, and degradation of monoclinic structure
  13. Thermal pressure in MgO and MgSiO3 perovskite at lower mantle conditions
  14. Electron energy-loss spectroscopy of silicate perovskite-magnesiowüstite high-pressure assemblages
  15. Magnesium coordination environments in glasses and minerals: New insight from high-field magnesium-25 MAS NMR
  16. In situ powder diffraction study of titanite (CaTiOSiO4) at high pressure and high temperature
  17. Surinamite: A high-temperature metamorphic beryllosilicate from Lewisian sapphirine-bearing kyanite-orthopyroxene-quartz-potassium feldspar gneiss at South Harris, N.W. Scotland
  18. Single-crystal X-ray diffraction study of FeGeO3 high-P clinopyroxene (C2/c) up to 8.2 GPa
  19. High-pressure Ca4Al6O13: An example of a calcium aluminate with three different types of coordination polyhedra for aluminum
  20. Cation distribution in synthetic zinc ferrite (Zn0.97Fe2.02O4) from in situ high-temperature neutron powder diffraction
  21. Infrared study of OH sites in tourmaline from the elbaite-schorl series
  22. Second occurrence of okayamalite, Ca2SiB2O7: chemical and TEM characterization
  23. Rietveld refinement of okayamalite, Ca2SiB2O7: Structural evidence for the B/Si ordered distribution
  24. Tumchaite Na2(Zr,Sn)Si4O11·2H2O—A new mineral from carbonatites of the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia
  25. The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18: A novel interrupted silicate framework
  26. Symesite, Pb10(SO4)O7Cl4(H2O), a new PbO-related sheet mineral: Description and crystal structure
  27. Na2Ca2(P2O7)F2, the first diphosphate of the cuspidine family
  28. Amphibole asbestos from Libby, Montana: Aspects of nomenclature
  29. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivines—Comment
  30. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivine—Reply
  31. Letter. Fivefold-coordinated aluminum in tectosilicate glasses observed by triple quantum MAS NMR
https://doi.org/10.2138/am-2000-1024

Articles in the same Issue

  1. Nucleation and growth kinetics of analcime from precursor Na-clinoptilolite
  2. Viscosities of granitic (sensu lato) melts: Influence of the anorthite component
  3. Geochemistry of pyroxene inclusions from the Warrumbungle Volcano, New South Wales, Australia
  4. Supersilicic clinopyroxene and silica exsolution in UHPM eclogite and pelitic gneiss from the Kokchetav massif, Kazakhstan
  5. Experimental study of intracrystalline Fe2+-Mg exchange in three augite crystals: Effect of composition on geothermometric calibration
  6. Transmission electron microscopy and differential thermal studies of lazurite polymorphs
  7. Re-equilibration of glass and CO2 inclusions in xenolith olivine: A TEM study
  8. Origin and structural character of haüyness in spinel dunite xenoliths from La Palma, Canary Islands
  9. Pyrrhotite varieties from the 9.1 km deep borehole of the KTB project
  10. Mineralogy and magnetic behavior of pyrrhotite from a 260 °C section at the KTB drilling site, Germany
  11. Surface defects and self-diffusion on pyrite {100}: An ultra-high vacuum scanning tunneling microscopy and theoretical modeling study
  12. Rare-earth elements in chlorapatite [Ca10(PO4)6Cl2]: Uptake, site preference, and degradation of monoclinic structure
  13. Thermal pressure in MgO and MgSiO3 perovskite at lower mantle conditions
  14. Electron energy-loss spectroscopy of silicate perovskite-magnesiowüstite high-pressure assemblages
  15. Magnesium coordination environments in glasses and minerals: New insight from high-field magnesium-25 MAS NMR
  16. In situ powder diffraction study of titanite (CaTiOSiO4) at high pressure and high temperature
  17. Surinamite: A high-temperature metamorphic beryllosilicate from Lewisian sapphirine-bearing kyanite-orthopyroxene-quartz-potassium feldspar gneiss at South Harris, N.W. Scotland
  18. Single-crystal X-ray diffraction study of FeGeO3 high-P clinopyroxene (C2/c) up to 8.2 GPa
  19. High-pressure Ca4Al6O13: An example of a calcium aluminate with three different types of coordination polyhedra for aluminum
  20. Cation distribution in synthetic zinc ferrite (Zn0.97Fe2.02O4) from in situ high-temperature neutron powder diffraction
  21. Infrared study of OH sites in tourmaline from the elbaite-schorl series
  22. Second occurrence of okayamalite, Ca2SiB2O7: chemical and TEM characterization
  23. Rietveld refinement of okayamalite, Ca2SiB2O7: Structural evidence for the B/Si ordered distribution
  24. Tumchaite Na2(Zr,Sn)Si4O11·2H2O—A new mineral from carbonatites of the Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia
  25. The crystal structure of thornasite, Na12Th3[Si8O19]4(H2O)18: A novel interrupted silicate framework
  26. Symesite, Pb10(SO4)O7Cl4(H2O), a new PbO-related sheet mineral: Description and crystal structure
  27. Na2Ca2(P2O7)F2, the first diphosphate of the cuspidine family
  28. Amphibole asbestos from Libby, Montana: Aspects of nomenclature
  29. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivines—Comment
  30. Thermodynamics of multicomponent olivines and the solution properties of (Ni,Mg,Fe)2SiO4 and (Ca,Mg,Fe)2SiO4 olivine—Reply
  31. Letter. Fivefold-coordinated aluminum in tectosilicate glasses observed by triple quantum MAS NMR
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