Diamond is an allotrope of Carbon. It has a crystalline lattice. In diamond each carbon atom undergoes sp3 hybridization and lined to four other carbon atoms by using hybridized orbitals in tetrahedral fashion. The C-C bond length is 154 pm. The structure extends in space and produces a rigid three-dimensional network of carbon atoms. In this structure directional covalent bonds are present throughout the lattice.

It is very difficult to break extended covalent bonding and therefore, diamond is a hardest substance on the earth.


  • It is used as an abrasive for sharpening hard tools.
  • It is used to manufacture of tungsten filaments for electric light bulbs.
  • It is used in making dies.