In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals. There are three main varieties of these crystals: \n* Primitive cubic (abbreviated cP and alternatively called simple cubic) \n* Body-centered cubic (abbreviated cI or bcc), \n* Face-centered cubic (abbreviated cF or fcc, and alternatively called cubic close-packed or ccp) Each is subdivided into other variants listed below. Note that although the unit cell in these crystals is conventionally taken to be a cube, the primitive unit cell often is not. This is related to the fact that in most cubic crystal systems, there is more than one atom per cubic unit cell. A classic isometric crystal has square or pentagonal faces.