Know all about Argillite and Theralite properties here. All properties of rocks are important as they define the type of rock and its application. Argillite belongs to Sedimentary Rocks while Theralite belongs to Igneous Rocks.Texture of Argillite is Clastic, Polished whereas that of Theralite is Phaneritic. Argillite appears Rough and Dull and Theralite appears Veined and Shiny. The luster of Argillite and Theralite is waxy and dull. Argillite and Theralite are available in dark grey to black, pink, red, white colors. The commercial uses of Argillite are fire resistant, used to manufracture paperweights and bookends and that of Theralite are cemetery markers, commemorative tablets, creating artwork, laboratory bench tops, jewelry, sea defence, tombstones.