Thermodynamic properties of wollastonite, pseudowollastonite and CaSiO3 glass and liquid
Richet, Pascal; Robie, Richard A.; Hemingway, Bruce S.
European Journal of Mineralogy Volume 3 Number 3 (1991), p. 475 - 484
published: Jun 14, 1991
manuscript accepted: Jan 8, 1991
manuscript received: Aug 13, 1990
ArtNo. ESP147050303001, Price: 29.00 €
Abstract Available thermodynamic data for wollastonite, pseudowollastonite and CaSiO3 glass and liquid have been reviewed and complemented to obtain a consistent set of thermodynamic properties: heat capacities, entropies, and temperatures and enthalpies of transition and fusion. Drop-calorimetry experiments for wollastonite between 800 and 1350 K show a first-order phase transition at 995 K with a small enthalpy of transition of 200 J/mol. From low-temperature Cpmeasurements between 10 and 370 K for CaSiO3 glass, the absolute and configurational entropies of the amorphous phases have been determined. The differences between the properties of wollastonite and pseudowollastonite are greater than suggested by current polyhedral modeling of the heat capacity.