Cleated coal
Cleated coal is not a separate type of fuel but a descriptive term used by geologists and mining engineers to refer to coal seams that contain a well-developed system of…
Fusain-rich coal
Fusain-rich coal is a distinctive variety of coal in which fragments of fossil charcoal, known collectively as fusain, are abundant. These coals preserve a record of ancient paleo-wildfires and the…
