TRENDS AND SYSTEMATICS IN MINERAL THERMODYNAMICS.

The stability of complex oxide and silicate phases can be understood in terms of equally important contributions of energy and entropy effects. The change in coordination number at high pressure in silicates has a profound effect on thermodynamic properties. Properties of spinel solid solutions can be systematized using a refined cation distribution model, while those of solid solutions involving no cation redistribution can be correlated with the volume mismatch of the end-members for a wide variety of structures and compositions. Ordering and exsolution in complex solid solutions is an important feature.