Lignite

Lignite, or Brown Coal, a rock of vegetable origin, generally retaining some of its original fibrous structure, yellow or pale brown to dark brown or black, with a specific gravity of 0-5 to 15, burning with a sooty flame, and often with a sulphurous smell, and leaving a good deal of ash. It contains from 55 to 75 per cent. of carbon, and is thus in all respects intermediate between peat (q.v.) and true coal. It varies in some characters according to its matrix. In the Lias and Kimeridge clays coniferous plants yield compact jet or Kimeridge coal, black, lustrous, and not fibrous; whilst in porous Jurassic limestones, rafts of drift wood still retain a brown colour, and much fibrous structure. In the Lower Eocene Laramie beds of the Rocky Mountains, our own Woolwich beds, the Oligocene Brown-coal beds of North Germany and the Lower Rhine, the Swiss Molasse and the Spitzbergen Miocene coal, the lignite, which is often black and lustrous, though largely coniferous, also consists largely of angiospermous plants. In North Germany it forms the chief fuel of the country.