Know all about Gabbro and Siltstone properties here. All properties of rocks are important as they define the type of rock and its application. Gabbro belongs to Igneous Rocks while Siltstone belongs to Sedimentary Rocks.Texture of Gabbro is Phaneritic whereas that of Siltstone is Clastic. Gabbro appears Veined and Shiny and Siltstone appears Rough. The luster of Gabbro is not available while that of Siltstone is dull. Gabbro is available in dark grey to black colors whereas Siltstone is available in brown, red, reddish brown colors. The commercial uses of Gabbro are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones and that of Siltstone are raw material for the manufacture of mortar, soil conditioner.