Dolomitization reaction (VR version)

3D Model

This model shows 6 Ca cations from a calcite (Ca[6]C[3]O3) unit cell being replaced by Mg to form perfectly ordered dolomite (Mg[6]Ca62) with simultaneous contraction of the crystal lattice to accommodate the smaller Mg ions before reversing back to calcite. Ion balls and bond sticks were positioned using Vesta (Momma and Izumi, 2011) using structural information from Graf (1961) for calcite and Steinfink and Sans (1959) for dolomite accessed using the the American Mineralogist Crystal Structure Database (http://rruff.geo.arizona.edu/AMS/); animation in Cinema4d. Purpose: to communicate differences between the minerals calcite and dolomite and the concept of a simple ionic substitution reaction (in this case- dolomitization/dedolomitization) to novice geoscientists. Concepts/processes explored: chemical reactions, crystallography, and unit cells.