Know all about Picrite and Coal properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Coal belongs to Sedimentary Rocks.Texture of Picrite is Earthy, Rough whereas that of Coal is Amorphous, Glassy. Picrite appears Rough and Shiny and Coal appears Veined or Pebbled. The luster of Picrite is subvitreous to dull while that of Coal is dull to vitreous to submetallic. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas Coal is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.