Graphite (Crystal Lattice)

A mineral is a naturally occurring homogeneous solid with a definite chemical composition and a highly ordered atomic arrangement. Minerals (crystals) have an ordered internal arrangement of atoms. This ordered arrangement shows symmetry, i.e. the atoms are arranged in a symmetrical fashion on a three dimensional network referred to as **a crystal lattice**.

**Graphite** has a layered, planar structure. In each layer, the carbon atoms are arranged in a hexagonal (honeycomb) lattice with a separation of 0.142 nm, and the distance between planes is 0.335 nm. Atoms in the plane are bonded covalently. Bonding between layers is via weak van der Waals forces, which allows layers of graphite to be easily separated, or to slide past each other.