Subsequently, the name was given to any igneous rocks with large crystals. The adjective "porphyritic" now refers to a certain texture of igneous rock regardless of its chemical and mineralogical composition. Its chief characteristic is a large difference in size between the tiny matrix crystals and the much larger phenocrysts. Porphyries may be aphanites or phanerites, that is, the groundmass may have microscopic crystals as in basalt, or crystals easily distinguishable with the eye, as in granite. Most types of igneous rocks display some degree of porphyritic texture.