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