Know all about Chalk and Siltstone properties here. All properties of rocks are important as they define the type of rock and its application. Chalk and Siltstone belong to Sedimentary Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Siltstone is Clastic. Chalk appears Soft and Siltstone appears Rough. The luster of Chalk and Siltstone is dull. Chalk is available in grey, white, yellow colors whereas Siltstone is available in brown, red, reddish brown 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 Siltstone are raw material for the manufacture of mortar, soil conditioner.