Since fundamental research in applied coal petrography is carried out mostly on polished surfaces, backscattered electron microscopy is most applicable for studying coal in the SEM. By employing this technique coal macerals can be easily identified , and information on the relations between maceral groups, mineral matter and trace elements are highlighted by grey level contrasts._x000D_
This type of information is valuable in coal technology and cannot by normally revealed by the light microscopy (e.g. the distribution of inherent mineral matter).