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