Structure of an elementary cell of diamond.                        Structure of diamond

Schematic of crystal faces:(111),octahedral face;(110),

rhombdodecahedral face;(100),cubic face.

The elementary cells are made up of carbon atoms. Each atom is surround by

four further atoms in a tetrahedral arrangement. The angle between bonds:109⁰28^’.

The smallest distance between atoms: 0.1544nm(1nm=1/10⁹m).

The constant of crystal lattice:0.35668nm.

                                                    Cleavage of diamond.

                                                                     Mixed Crystals

                     O=octahedral. C=cube. D=rhombic dodecahedral.