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