Lignite is one of the important type of rocks. If we have to define Lignite in general, Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat. Lignite comes under Sedimentary Rocks. All Sedimentary Rocks have similar properties and formation process. Along with Lignite Definition, know more about the History of Lignite, Etymology of Lignite in next sections.