Halite (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 **.

** Halite ** contains each of the two atom types (sodium and chlorine) forming a separate face-centered cubic lattice, with the two lattices interpenetrating so as to form a 3D checkerboard pattern. The face centered cubic lattice consists of the atoms (lattice points) identified in the corners and the center of each of the six faces of the cube. The length of the side of the unit cell is 0.564 nm. Ionic bonding are formed between sodium cations and chloride anions.