The word originally took the form col in Old English, from Proto-Germanic *kula(n), which in turn is hypothesized to come … See more

Coal is composed of macerals, minerals, and water. Fossils and amber may be found in coal.
The conversion of dead vegetation into coal is called coalification. At various times in the geologic pa… See more

The earliest recognized use is from the Shenyang area of China where by 4000 BC Neolithic inhabitants had begun carving ornaments from black lignite. Coal from the Fushun mine in northeastern China was used to smelt … See more

The composition of coal is reported either as a proximate analysis (moisture, volatile matter, fixed carbon, and ash) or an ultimate analysis (ash, carbon, hydrogen, nitrogen, oxygen, and sulfur). The "volatile matter" doe… See more

The energy density of coal is roughly 24 megajoules per kilogram (approximately 6.7 kilowatt-hours per kg). For a coal power plant with a 40% efficiency, it takes an estimated 325 kg (717 lb) of coal to power a 100 W light… See more

About 8,000 Mt of coal are produced annually, about 90% of which is hard coal and 10% lignite. As of 2018 just over half is from underground mines. More accidents occur during underground mining than surface min… See more

The use of coal as fuel causes health problems and deaths. The mining and processing of coal causes air and water pollution. Coal-powered plants emit nitrogen oxides, sulfur dioxide, particulate pollution, a… See more