Thermal Studies of Some Minerals, No. 3.: On Thermal Transformation of Antigorite in Air

The pulverized specimens of antigorite were subjected to the thermal treatments at various temperatures up to 1000°C in the air, and the effects of dehydration together with recrystallization were pursued by means of DTA, TGA, X-ray diffraction, infrared absorption spectroscopy and electron microscopy.
The results obtained evidently suggest that emergence of the shoulder-like endothermic and exothermic peakes on the DTA curve is ascribed to destruction of the super-lattice structure of the original antigorite and production of the "mosaic olivine" during dehydration respectively and that under electron microscopic observation the recrystallized olivines with various shapes showing the specific relationships to orientation of the original mineral, controlled by the position, are discernible.