ABSTRACT
The following text uses some basic notions and terminology, and abbreviations that are broadly applicable in the field of geochemistry.
The combustible part of coal (in which enter C, O, N, and a part of S) is named as organic, and all the rest is named as inorganic, in spite of the fact that this list includes the same chemical elements: C (in carbonates), N and O (in silicates and the other minerals), and S (in sulfides and sulfates). There is no logic in such division, but this is an old geological tradition.
