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