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