Article
Licensed
Unlicensed Requires Authentication

Crystal chemistry of the new mineral brandholzite, Mg(H2O)6[Sb(OH)6]2, and of the synthetic analogues M2+(H2O)6[Sb(OH)6]2 (M2+ = Mg, Co)

  • EMAIL logo , , and
Published/Copyright: March 26, 2015
Become an author with De Gruyter Brill
Author Information
American Mineralogist
From the journal American Mineralogist Volume 85 Issue 3-4

Abstract

Brandholzite, a new magnesium antimony hydroxide hydrate mineral, Mg(H2O)6[Sb(OH)6]2, has been discovered in Au-Sb-Quartz veins of the former mining district of Brandholz-Goldkronach, Fichtelgebirge, Germany. The new mineral is associated with stibnite and antimony-ochers and forms colorless, platelike crystals up to ~1 mm in size. Natural as well as synthetic samples obtained by slow evaporation of an aqueous solution exhibit {101̅0} twinning, leading to a pronounced ̅3̅1m pseudo-symmetry. The crystal structures of brandholzite and its synthetic analogue were investigated using single crystal X-ray CCD data: trigonal, space group P3, Z = 6, a = 16.119(1) Å, c = 9.868(1) Å, R1 = 0.034 for 14788 Fo > 4σ(Fo) (brandholzite), and a = 16.113(1) Å, c = 9.868(1) Å, R1 = 0.029 for 16624 Fo > 4σ(Fo) (synthetic analogue) and 525 variable parameters each. The structures are isotypic with bottinoite, Ni(H2O)6[Sb(OH)6]2, and are built up by nearly regularly shaped, isolated Mg(H2O)6 and Sb(OH)6 octahedra which are interconnected by hydrogen bonds only. The strongest lines in the powder pattern are [d-value (Å), I, hkl]: 4.636, 100, (300); 3.392, 70, (302); 4.946, 50, (002); 2.356, 40, (332). At 589 nm, the mineral is optically uniaxial negative with refractive indices nω = 1.570(2) and nε = 1.569(2). The crystal structure of the pseudo-isotypic synthetic compound Co(H2O)6[Sb(OH)6]2 was also investigated: trigonal, space group P3, a = 16.105(1), c = 9.851(1), Z = 6, R1 = 0.051 for 13516 reflections with Fo > 4σ(Fo) and 525 parameters. Compared to the Mg-antimonates and bottinoite, a significant rotation of some Sb(OH)6 octahedra is observed in Co(H2O)6[Sb(OH)6]2.

Received: 1999-5-19
Accepted: 1999-11-8
Published Online: 2015-3-26
Published in Print: 2000-4-1

© 2015 by Walter de Gruyter Berlin/Boston

Articles in the same Issue

  1. Iron concentration and the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass
  2. A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies
  3. Mineralogy of mafic xenoliths and their reaction zones in the olivine lamproite from Prairie Creek Arkansas and the paragenesis of haggertyite, Ba [Fe6Ti5Mg]O19
  4. Magmatic anhydrite in granitic rocks: First occurrence and potential petrologic consequences
  5. Crystal chemistry of Al-rich biotites coexisting with muscovites in peraluminous granites
  6. Spectroscopic and structural properties of synthetic micas on the annite-siderophyllite binary: Synthesis, crystal structure refinement, Mössbauer, and infrared spectroscopy
  7. Thermodynamic properties of tremolite: A correction and some comments
  8. Raman spectroscopic characteristics of Mg-Fe-Ca pyroxenes
  9. Hydrogen in diopside: Diffusion profiles
  10. Diffusion of C and O in calcite at 100 MPa
  11. Solubility and stability of zeolites in aqueous solution: II. Calcic clinoptilolite and mordenite
  12. TEM and SFM of exsolution and twinning in an alkali feldspar
  13. Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure
  14. Optimization of site occupancies in minerals using quadratic programming
  15. Leverage analysis and structure refinement of minerals
  16. The absolute energy positions of conduction and valence bands of selected semiconducting minerals
  17. Antiferroelectric phase transition in titanite: Excess entropy and short range order
  18. P4/n and P4nc long-range ordering in low-temperature vesuvianites
  19. Tetrahedral vacancies and cation ordering in low-temperature Mn-bearing vesuvianites: Indication of a hydrogarnet-like substitution
  20. Sodic-ferripedrizite, a new monoclinic amphibole bridging the magnesium-iron-manganese-lithium and the sodium-calcium groups
  21. The crystal structure of peprossiite-(Ce), an anhydrous REE and Al mica-like borate with square-pyramidal coordination for Al
  22. Crystal chemistry of the new mineral brandholzite, Mg(H2O)6[Sb(OH)6]2, and of the synthetic analogues M2+(H2O)6[Sb(OH)6]2 (M2+ = Mg, Co)
  23. Letters. In-situ Raman spectra of dissolved silica species in aqueous fluids to 900 °C and 14 kbar
  24. Quetzalcoatlite: A new octahedral-tetrahedral structure from a 2 × 2 × 40 μm3 crystal at the Advanced Photon Source-GSE-CARS Facility
  25. Bonding and dynamics of Mg in pyrope: a theoretical investigation
  26. Structure of a new Al-rich phase, [K, Na]0.9[Mg, Fe]2[Mg, Fe, Al, Si]6O12, synthesized at 24 GPa
  27. Core level electron binding energies of realgar (As4S4)
  28. Oxidation of {100} and {111} surfaces of pyrite: Effects of preparation method
https://doi.org/10.2138/am-2000-0422

Articles in the same Issue

  1. Iron concentration and the physical processes of dynamic oxidation in an alkaline earth aluminosilicate glass
  2. A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies
  3. Mineralogy of mafic xenoliths and their reaction zones in the olivine lamproite from Prairie Creek Arkansas and the paragenesis of haggertyite, Ba [Fe6Ti5Mg]O19
  4. Magmatic anhydrite in granitic rocks: First occurrence and potential petrologic consequences
  5. Crystal chemistry of Al-rich biotites coexisting with muscovites in peraluminous granites
  6. Spectroscopic and structural properties of synthetic micas on the annite-siderophyllite binary: Synthesis, crystal structure refinement, Mössbauer, and infrared spectroscopy
  7. Thermodynamic properties of tremolite: A correction and some comments
  8. Raman spectroscopic characteristics of Mg-Fe-Ca pyroxenes
  9. Hydrogen in diopside: Diffusion profiles
  10. Diffusion of C and O in calcite at 100 MPa
  11. Solubility and stability of zeolites in aqueous solution: II. Calcic clinoptilolite and mordenite
  12. TEM and SFM of exsolution and twinning in an alkali feldspar
  13. Equation of state of magnetite and its high-pressure modification: Thermodynamics of the Fe-O system at high pressure
  14. Optimization of site occupancies in minerals using quadratic programming
  15. Leverage analysis and structure refinement of minerals
  16. The absolute energy positions of conduction and valence bands of selected semiconducting minerals
  17. Antiferroelectric phase transition in titanite: Excess entropy and short range order
  18. P4/n and P4nc long-range ordering in low-temperature vesuvianites
  19. Tetrahedral vacancies and cation ordering in low-temperature Mn-bearing vesuvianites: Indication of a hydrogarnet-like substitution
  20. Sodic-ferripedrizite, a new monoclinic amphibole bridging the magnesium-iron-manganese-lithium and the sodium-calcium groups
  21. The crystal structure of peprossiite-(Ce), an anhydrous REE and Al mica-like borate with square-pyramidal coordination for Al
  22. Crystal chemistry of the new mineral brandholzite, Mg(H2O)6[Sb(OH)6]2, and of the synthetic analogues M2+(H2O)6[Sb(OH)6]2 (M2+ = Mg, Co)
  23. Letters. In-situ Raman spectra of dissolved silica species in aqueous fluids to 900 °C and 14 kbar
  24. Quetzalcoatlite: A new octahedral-tetrahedral structure from a 2 × 2 × 40 μm3 crystal at the Advanced Photon Source-GSE-CARS Facility
  25. Bonding and dynamics of Mg in pyrope: a theoretical investigation
  26. Structure of a new Al-rich phase, [K, Na]0.9[Mg, Fe]2[Mg, Fe, Al, Si]6O12, synthesized at 24 GPa
  27. Core level electron binding energies of realgar (As4S4)
  28. Oxidation of {100} and {111} surfaces of pyrite: Effects of preparation method
Downloaded on 14.4.2026 from https://www.degruyterbrill.com/document/doi/10.2138/am-2000-0422/html
Scroll to top button