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