Know all about Coal and Theralite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Theralite belongs to Igneous Rocks.Texture of Coal is Amorphous, Glassy whereas that of Theralite is Phaneritic. Coal appears Veined or Pebbled and Theralite appears Veined and Shiny. The luster of Coal is dull to vitreous to submetallic while that of Theralite is waxy and dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Theralite is available in dark grey to black 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 Theralite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.