Characteristics related to grain size of rocks are called as texture. Here you can know more about texture of Greywacke and Variolite. Texture of Greywacke is Clastic whereas that of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular. Based on the texture of rocks, they are used for various purposes. Get detailed information about Greywacke vs Variolite texture, color, appearance and maintenance in the next section.