Know all about Coal and Harzburgite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Harzburgite belongs to Igneous Rocks.Texture of Coal is Amorphous, Glassy whereas that of Harzburgite is Phaneritic. Coal appears Veined or Pebbled and Harzburgite appears Rough and Shiny. The luster of Coal is dull to vitreous to submetallic while that of Harzburgite is shiny. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Harzburgite is available in dark greenish - grey 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 Harzburgite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.