3. Close Packing of Spheres - The Hexagonal Lattice

In a plane, spheres can be arranged in a plane in such a way that each ball touches exactly six other balls. This is the hexagonal lattice.

In this case, the planes are closer packed than in the square arrangement. But a ball placed in a nest formed by a cluster of three balls does not sink as deep as a ball placed in a nest of a cluster formed by four balls - as we have seen in the square arrangement.

As seen previously in the square arrangement, again each ball in the hexagonal arrangement also has exactly twelve neighbors in space. In this there are three balls in the plane below, six balls in the same plane and three balls in the plane above.