Crystal chemical examinations of complex mineral structures

Crystal chemical examinations of complex mineral structures. These crystal structures may be divided into two parts (1) the structural unit, an array of high bond-valence polyhedra and (2) the interstitial complex, an array of large low valence cations, simple anions and (H2O) groups. Our examination have been focussed on (a) the topology of these complex structures, i.e. the three-dimensional arrangement of the structural units; (b) the bond-lengths and bond-valences in the structural units; the interaction between structural units and interstitial complexes, i.e. how does the structural unit determine the chemical composition of an interstitial complex; (c) occurrence of structural units under different geochemical conditions (pH/Eh). Further projects are in-situ AFM examination of dissolution processes of structural units and X-ray crystallographic examinations of mineral and inorganic structures.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Dr. Michael Schindler, Frank Eidam, Petre Mandeliev, Andreas Mutter

Veröffentlichungen:

M.Schindler, W. Joswig and W. H. Baur: Na3V4+O(PO4)(HPO4), a new phase in the Na /V /P /H2O system under hydrothermal conditions at 473 K. J. Solid State Chem. 145, 15-22, (1999)

D.K. Teertstra, M.Schindler, B.L. Sheriff and F.C. Hawthorne: Silvialite, a new sulfate-dominant member of the scapolite group with an Al-Si composition near the I4/m - P42/n phase transition. Mineral. Mag. 63, 321-329, (1999)

M.Schindler and F.C. Hawthorne: Schubnelite, Fe3+(V5+O4)(H2O), a novel heteropolyhedral framework mineral. Am. Mineral. 84, 665-668, 1999

M. Schindler and F. C. Hawthorne: Structural characterization of the $-Cu2V2O7 - "-Zn2V2O7 solid solution J. Solid State Chem. 146, 271-276, (1999)

M. Schindler, F.C. Hawthorne and W.H. Baur: Metastructures: Homeomorphisms between complex inorganic structures and three-dimensional nets. Acta Crystallgr. B. B55, 811-829, (1999)

M.Schindler, F.C. Hawthorne and W.H. Baur: The crystal chemistry of vanadium: polyhedra geometries, characteristic bond valences and polymerisation of (VOn) polyhedra. Chem. Mater. 12, 5, 1248-1259, (2000)

M. Schindler and F. C. Hawthorne: The crystal structure of schulingite -Nd. Can. Miner. 37, 1463-1470, (2000)

F.C. Hawthorne and M.Schindler: Enumeration of Cu2+ sulphate structures based on decorated [MN2]n sheets. Can. Miner. 38, 751-761, (2000)

M.Schindler, F.C. Hawthorne and W.H. Baur: A crystal-chemical approach to the composition and occurrence of vanadium minerals. Can. Mineral. 38, 1443-1456, (2000)

M.Schindler, D.C. Humminicki and F.C. Hawthorne: A bond-valence approach to the chemical composition and occurrence of sulfate minerals. GSA conference, Reno, USA, (2000)