Know all about Coal and Marl properties here. All properties of rocks are important as they define the type of rock and its application. Coal and Marl belong to Sedimentary Rocks.Texture of Coal is Amorphous, Glassy whereas that of Marl is Earthy. Coal appears Veined or Pebbled and Marl appears Rough and Dull. The luster of Coal is dull to vitreous to submetallic while that of Marl is dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Marl is available in beige, brown, green, grey, white colors. The commercial uses of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry and that of Marl are creating artwork, soil conditioner.