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