Andesite is an extrusive volcanic rock in composition ranging between rhyolite and basalt. It has a typical porphyritic texture, being that of full-grown crystals or crystal filled cavities floating in an amorphous groundmass of solid lava. This porphyritic texture is caused by exsolution, a process of separation that takes place during successive phases of crystallisation and solidification in the lava. Sample is from Carboneras on the southern coast of Spain, featuring an andesite with crystals of plagioclase, hornblende and pyroxene afloat in a light coloured, amorphous groundmass. Sample's actual width is 110 mm.