Know all about Siltstone and Andesite properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Andesite belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Andesite is Aphanitic to Porphyritic. Siltstone appears Rough and Andesite appears Dull and Soft. The luster of Siltstone is dull while that of Andesite is vitreous. Siltstone is available in brown, red, reddish brown colors whereas Andesite is available in bluish - grey, grey, pink, yellow colors. The commercial uses of Siltstone are raw material for the manufacture of mortar, soil conditioner and that of Andesite are commemorative tablets, creating artwork.