Brief Description: It is coal, amorphous and it belongs to the self-sown elements. It constitutes one of the fist products of carbonation and it is an intermediate material between peat and bituminous coal. Its lustre is dull, vitreous and resinous and its colour brown (the main lignite) or black (the black lignite). It is opaque with hardness 1 - 1½ and specific gravity 0.5 ? 1.5. It lights up easily, burns with a flame that fumes and smells of asphalt. It usually occurs in the form of fibrous aggregates. It occurs in deposits of fresh or brackish phases of Mesozoic and Cainozoic century, along with sandstone, clay, marl etc. In Greece, similar formations can be found in Pleistocene as well. Its carbon content is 60-75%. Its thermal value is 7,000-11,000 BTU. Even though it has a relatively small thermal value, it is used almost exclusively as a mineral fuel. Black lignite is used many times for decorative purpose as well. 
Bibliography: Ευρετήριο ορυκτών ΑΠΘ στην ιστοσελίδα http://www.geo.auth.gr/106/az_gr.htm Τσιραμπίδης Α. (2005). Ο ορυκτός πλούτος της Ελλάδας. Εκδόσεις Γιαχούδη Θεσσαλονίκη, σελ. 391. Berry, L.G., Mason, B. and Dietrich, R.V. (1983). Mineralogy. W. H. Freeman and Company, San Francisco, 561 pp. Σαπουντζής, Η. και Χριστοφίδης, Γ. (1985). Ορυκτοδιαγνωστική. University Studio Press, Θεσσαλονίκη, 241 σ.