Know all about Argillite and Siltstone properties here. All properties of rocks are important as they define the type of rock and its application. Argillite and Siltstone belong to Sedimentary Rocks.Texture of Argillite is Clastic, Polished whereas that of Siltstone is Clastic. Argillite appears Rough and Dull and Siltstone appears Rough. The luster of Argillite is waxy and dull while that of Siltstone is dull. Argillite is available in dark grey to black, pink, red, white colors whereas Siltstone is available in brown, red, reddish brown colors. The commercial uses of Argillite are fire resistant, used to manufracture paperweights and bookends and that of Siltstone are raw material for the manufacture of mortar, soil conditioner.