Know all about Coal and Hawaiite properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Hawaiite belongs to Igneous Rocks.Texture of Coal is Amorphous, Glassy whereas that of Hawaiite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Coal appears Veined or Pebbled and Hawaiite appears Dull and Soft. The luster of Coal is dull to vitreous to submetallic while that of Hawaiite is not available. Coal and Hawaiite are available in black, brown, dark brown, grey, light to dark 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 Hawaiite are creating artwork, sea defence.