Home Veatchite: Structural relationships of the three polytypes
Article
Licensed
Unlicensed Requires Authentication

Veatchite: Structural relationships of the three polytypes

  • Joel D. Grice EMAIL logo and Allan Pring
Published/Copyright: April 2, 2015
Become an author with De Gruyter Brill

Abstract

Crystal structures of the three polytypes of veatchite, Sr2B11O16(OH)5·H2O, are determined by X-ray, single-crystal studies. The polytypes are: veatchite-1A, triclinic space group P1̄, with a = 6.6378(6), b = 6.7387(6), c = 20.982(2) Å, α = 87.860(1), β = 82.696(12), γ = 60.476(1)°, V = 809.7(2) Å3; veatchite-1M, monoclinic space group P21, with a = 6.7127(4), b = 20.704(1), c = 6.6272(4) Å, β = 119.209(1)°, V = 805.4(2) Å3; and veatchite-2M,monoclinic space group Cc with a = 6.6070(3), b = 11.7125(5), c = 20.6848(9) Å, β = 91.998(1)°, V = 1599.7(2) Å3. The crystal structures have two layer types with similar fundamental building blocks: A layer FBB = 3Δ2□:<Δ2□>-<2Δ□> and B layer FBB = 3Δ2□,1Δ:<Δ2□>-<2Δ□>,Δ (Grice et al. 1999). Unique in this FBB is the lone polyhedron with triangular coordination, which consists of a neutrally charged [B(OH)3] group. Layering has a directional component and depending on layer sequence the symmetry may be centrosymmetric or non-centrosymmetric. Related layered borate structures, biringuccite, nasinite, gowerite, and volkovskite, are compared. Observations indicate that veatchite-1A is the low-temperature and low-pressure polytype, veatchite-1M the high-temperature polytype, and veatchite-2M the moderate temperature and higher pressure polytype.

Received: 2011-5-18
Accepted: 2011-11-29
Published Online: 2015-4-2
Published in Print: 2012-4-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Veatchite: Structural relationships of the three polytypes
  2. Falsterite, Ca2MgMn2+2 (Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14, a new secondary phosphate mineral from the Palermo No. 1 pegmatite, North Groton, New Hampshire
  3. Pavlovskyite Ca8(SiO4)2(Si3O10): A new mineral of altered silicate-carbonate xenoliths from the two Russian type localities, Birkhin massif, Baikal Lake area and Upper Chegem caldera, North Caucasus
  4. Zaccagnaite-3R, a new Zn-Al hydrotalcite polytype from El Soplao cave (Cantabria, Spain)
  5. Incorporation of Si into TiO2 phases at high pressure
  6. TOF-SIMS and electron microprobe investigations of zoned magmatic orthopyroxenes: First results of trace and minor element analysis with implications for diffusion modeling
  7. Titanium in muscovite, biotite, and hornblende: Modeling, thermometry, and rutile activities of metapelites and amphibolites
  8. Polysaccharide-catalyzed nucleation and growth of disordered dolomite: A potential precursor of sedimentary dolomite
  9. High-pressure and high-temperature phase transitions in FeTiO3 and a new dense FeTi3O7 structure
  10. Compressibility and thermal expansion of hydrous ringwoodite with 2.5(3) wt% H2O
  11. Vibrational and elastic properties of ferromagnesite across the electronic spin-pairing transition of iron
  12. Electronic spin states of ferric and ferrous iron in the lower-mantle silicate perovskite
  13. Experimental VNIR reflectance spectroscopy of gypsum dehydration: Investigating the gypsum to bassanite transition
  14. Nature of rehydroxylation in dioctahedral 2:1 layer clay minerals
  15. Thermal behavior of afghanite, an ABABACAC member of the cancrinite group
  16. Experimental incorporation of Th into xenotime at middle to lower crustal P-T utilizing alkali-bearing fluids
  17. Sol-gel synthesis of nanocrystalline fayalite (Fe2SiO4)
  18. The heat capacity of fayalite at high temperatures
  19. Structural trends for celestite (SrSO4), anglesite (PbSO4), and barite (BaSO4): Confirmation of expected variations within the SO4 groups
  20. The dehydroxylation of serpentine group minerals
  21. Formation of nanoscale Th-coffinite
  22. Magnetic and low-temperature structural behavior of clinopyroxene-type FeGeO3: A neutron diffraction, magnetic susceptibility, and 57Fe Mössbauer study
  23. Crystal structure and thermal expansion of aragonite-group carbonates by single-crystal X-ray diffraction
  24. The lower-pressure stability of glaucophane in the presence of paragonite and quartz in the system Na2O-MgO-Al2O3-SiO2-H2O
  25. Coralloite, Mn2+Mn23+(AsO4)2(OH)2·4H2O, a new mixed valence Mn hydrate arsenate: Crystal structure and relationships with bermanite and whitmoreite mineral groups
  26. The crystal structure of metanatroautunite, Na[(UO2)(PO4)](H2O)3, from the Lake Boga Granite, Victoria, Australia
  27. Petedunnite (CaZnSi2O6): Stability and phase relations in the system CaO-ZnO-SiO2
  28. Revision of the crystal structure and chemical formula of weeksite, K2(UO2)2(Si5O13)·4H2O
  29. Electron backscatter diffraction (EBSD) analyses of phyllosilicates in petrographic thin sections
Downloaded on 16.9.2025 from https://www.degruyterbrill.com/document/doi/10.2138/am.2012.3889/html
Scroll to top button