Concluding Remarks

We have shown that the Fe-Mg exchange reaction between garnet and biotite can be modelled using the Elle data structure. Hybrid types of nodes (nodes and unodes) are used for the calculation of diffusive mass transfer along grain boundaries and within the volume of garnet and biotite. However, there are major limitations due to reduced dimensions in the model and unknown reaction constant at the interface. There are also uncertainties in algorithm when calculating the local equlibrium. In spite of these limitations and uncertainties, we feel that the model presented here can be at least a good starting point to model diffusive mass transfer in a material with grain boundary structure.