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