One type of organic deposits is Leonardite mineral. These are formations that cannot yet be called coal because they contain more water and organic matter within them. They cannot be called fuel because they burn weakly. Essentially, leonardite is a soft brown coal, the initial stage of its formation, although its age is measured in millions of years. The main value of such coal-like substance lies in its high content of humic acids. It is mined and used in the production of humic fertilizers.
