Know all about Siltstone and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Picrite belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Picrite is Earthy, Rough. Siltstone appears Rough and Picrite appears Rough and Shiny. The luster of Siltstone is dull while that of Picrite is subvitreous to dull. Siltstone is available in brown, red, reddish brown colors whereas Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors. The commercial uses of Siltstone are raw material for the manufacture of mortar, soil conditioner and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).