Know all about Chalk and Coal properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Coal belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Coal is Amorphous, Glassy. Chalk appears Soft and Coal appears Veined or Pebbled. The luster of Chalk is dull while that of Coal is dull to vitreous to submetallic. Chalk is available in grey, white, yellow colors whereas Coal is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper and that of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.