Variant of NAPCS Canada 2017 Version 1.0 - Manufacturing and Logging

144 - Coal

This group comprises coal, a combustible black (hard coal) and brownish-black (brown coal) rock consisting of more than 50 percent by weight and more than 70 percent by volume of carbonaceous material. It is formed from plant remains that have been compacted, hardened and chemically altered, and metamorphosed by heat and pressure over geologic time.