The microstructure of coal is determined and characterized by combined scanning election microscope-energy dispersive analysis techniques. Microstructural information on a micrometer-size scale is correlated with microchemical information developed by energy dispersive X-ray microanalyses to establish the presence and distribution of pyrite, the primary sulfur-bearing inorganic phase in coal. Other complementary analytic techniques are also used. This study evaluates particle size, shape, and distribution factors which bear on decisions to try to remove additional sulfide particles to reduce the sulfur content. Subsamples are obtained from complete channel samples or sources such as raw material prepared as appropriate to the major methods of coal conversion.