Know all about Argillite and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Argillite belongs to Sedimentary Rocks while Nephelinite belongs to Igneous Rocks.Texture of Argillite is Clastic, Polished whereas that of Nephelinite is Aphanitic. Argillite appears Rough and Dull and Nephelinite appears Skeletal. The luster of Argillite is waxy and dull while that of Nephelinite is vitreous to metallic. Argillite is available in dark grey to black, pink, red, white colors whereas Nephelinite is available in black, brown, colourless, green, grey, white colors. The commercial uses of Argillite are fire resistant, used to manufracture paperweights and bookends and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).