Know all about Siltstone and Trachyte properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Trachyte belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Trachyte is Aphanitic to Porphyritic. Siltstone appears Rough and Trachyte appears Banded. The luster of Siltstone is dull while that of Trachyte is metallic. Siltstone is available in brown, red, reddish brown colors whereas Trachyte is available in black, brown, dark greenish - grey, green, grey, light to dark grey, white colors. The commercial uses of Siltstone are raw material for the manufacture of mortar, soil conditioner and that of Trachyte are cemetery markers, creating artwork.