Other Reuleaux polygons are used to drill pentagonal, hexagonal, and octagonal holes. Weight shapes include round, hexagonal, or rectangular. The columns themselves may be organized into rectangular or hexagonal arrays. The pellicle is not smooth, but textured with hexagonal or rectangular depressions. Edo Kibashi chopsticks, which are pentagonal hexagonal or octagonal, make them easy to hold. Many of these designs can include systems employing cylindrical, hexagonal, or spherical ceramic pieces. Pencils are commonly round, hexagonal, or sometimes triangular in section. Ideal models such as cylindrical, hexagonal and square models are common. Commonly crowbars are forged from long steel products, either hexagonal or sometimes cylindrical stock. It shares graphene's hexagonal honeycomb structure. Crab pots are rigid boxlike traps made of hexagonal or square wire mesh. There are 3 types of monohedral convex hexagonal tilings. In total there are six crystal families&colon; triclinic, monoclinic, orthorhombic, tetragonal, hexagonal, and cubic. Beryl occurs in the shape of either a pebble or of an hexagonal prism. Fluorapatite crystallizes in a hexagonal crystal system.