Know all about Siltstone and Tonalite properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Tonalite belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Tonalite is Phaneritic. Siltstone appears Rough and Tonalite appears Banded and Foilated. The luster of Siltstone is dull while that of Tonalite is subvitreous to dull. Siltstone is available in brown, red, reddish brown colors whereas Tonalite 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 Tonalite are cemetery markers, creating artwork.