The main objectives of this paper are: 1) to summarize the geology, lithology and mineralogy of the overburden of each of the two sites; 2) to evaluate the lithology and mineralogy of the pyrometamorphic rocks formed by the experimental burns; 3) to show the distribution of the pyrometamorphic rocks and minerals at the two sites; 4) to compare the spatial distribution of minerals, textural features and lithologies of pyrometamorphic rocks at the two sites; 5) to compare the temperatures estimated from pyrometamorphic minerals with those measured with the thermocouples during the experiments; and 6) to suggest how the results of the two studies discussed here may be applied to underground coal gasification technology.