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