Abstract
We have investigated crystallization of amorphous silicate with the chondritic chemical composition. The amorphous sample was synthesized by the Sol-Gel method that has an advantage to get homogeneous amorphous materials at relatively low temperature without loss of volatile elements. The starting material was annealed at constant temperatures (660 – 758oC) for different durations (0.5 – 12 hrs). The experimental charges were examined by infrared absorption spectroscopy, X-ray diffraction and scanning electron microscopy / energy dispersive X-ray spectroscopy. On the spectrum of the initial amorphous sample, broad and smooth absorption features were observed at approximately 10 and 20 micrometers, that are typical for amorphous silicate originated from Si-O stretching and O-Si-O bending vibration modes. On the spectra of the annealed samples, sharp and prominent features of olivine appeared. The present results show that the crystallization kinetics is different from previous experiments for silicate with a simple composition (e.g. Hallenbeck et al., 1998).
