Know all about Coal and Icelandite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Icelandite belongs to Igneous Rocks.Texture of Coal is Amorphous, Glassy whereas that of Icelandite is Aphanitic to Porphyritic. Coal appears Veined or Pebbled and Icelandite appears Dull and Soft. The luster of Coal is dull to vitreous to submetallic while that of Icelandite is vitreous. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Icelandite is available in bluish - grey, grey, pink, yellow 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 Icelandite are cemetery markers, creating artwork.