Know all about Siltstone and Trachyandesite properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Trachyandesite belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Trachyandesite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Siltstone appears Rough and Trachyandesite appears Dull and Soft. The luster of Siltstone is dull while that of Trachyandesite is earthy. Siltstone is available in brown, red, reddish brown colors whereas Trachyandesite is available in black, brown, light to dark grey colors. The commercial uses of Siltstone are raw material for the manufacture of mortar, soil conditioner and that of Trachyandesite are creating artwork, pottery.