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Free keywords:
chlorartinite; magnesia cement; dehydration; powder diffraction
Abstract:
In the course of an investigation of cracks in certain magnesia floors containing the mineral chlorartinite [Mg-2(CO3)(H2O)(OH)]Cl center dot H2O, the dehydration process of chlorartinite was carried out in high vacuum. The crystal structure of dehydrated chlorartinite [Mg-2(CO3)(H2O)(OH)]Cl was refined from laboratory X-ray powder diffraction data using the Rietveld method [R3c, a=22.6791(5) angstrom, c=7.22336(14) angstrom, V=3217.52(11) angstrom(3), Z=18, R-p=4.13%, R-wp=5.82%]. Dehydrated chlorartinite exhibits the same type of 3D honeycomb zeolite-like crystal structure with large channels as the hydrated form. Compared to the hydrated form, the channels of dehydrated chlorartinite are empty because of the removal of all non-coordinating water molecules with the cell volume shrinking by 4.0%, leading to a more distorted environment of the magnesium atoms. (C) 2007 International Centre for Diffraction Data.
