6533b839fe1ef96bd12a6d82
RESEARCH PRODUCT
Prehnite: Structural similarity of the monoclinic and orthorhombic polymorphs and their Si/Al ordering
Werner H. BaurWerner JoswigDethard KassnerWolfgang Hofmeistersubject
Materials scienceMineralCoordination sphereengineering.materialCondensed Matter PhysicsSilicateElectronic Optical and Magnetic MaterialsInorganic Chemistrychemistry.chemical_compoundPrehniteCrystallographychemistryAtomMaterials ChemistryCeramics and CompositesTetrahedronengineeringOrthorhombic crystal systemPhysical and Theoretical ChemistryMonoclinic crystal systemdescription
Abstract Two modifications of the naturally occurring mineral prehnite, Ca 2 Al(Si 3 AlO 10 )(OH) 2 , are characterized by precise single crystal diffraction methods. The two forms are topologically identical. They differ only in the siting of one Al and one Si atom per unit cell: these switch their places in two of the tetrahedrally coordinated sites. This appears to be the only known case where a silicate occurs with two differently ordered tetrahedral distributions of Al and Si atoms. The two forms are not polytypes according to the current definition of polytypes. The two modifications are so similar to each other that they differ only in the eighth coordination sphere.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1990-06-01 | Journal of Solid State Chemistry |