A full statistical analysis of the microstructure of glass-ceramic solid oxide fuel cell (SOFC) seal material, G18, is performed to calculate elastic properties. Predictions are made for samples aged for 4h and 1000 h, giving different crystallinity levels. Microstructure of the glass-ceramic G18 is characterized by correlation function for each individual phase. Predicted results are compared with the Voigt and Reuss bounds in this study. The weak contrast analysis results in elastic modulus predictions between the upper and lower bounds but closer to the upper bound. (C) 2010 Elsevier B.V. All rights reserved.