Minerals A Rock is a naturally formed, consolidated material composed of grains of one or more minerals. Granite is a rock composed of grains of several minerals including feldspar and quartz. A Mineral is composed of atoms arranged in a very orderly, three-dimensional structure which is to say it is crystalline. In the crystalline lattice each sodium atom is surrounded by six chlorine atoms and each chlorine atom is surrounded by six sodium atoms.
Most rocks are crystalline.
It must be a crystalline solid. It must occur naturally. It must be inorganic 4. It must have a definite chemical composition. Streak - the color of scraping the edge of a mineral across an unglazed porcelain plate.