All the bonds are sp 3 hybridized. The bond angles are at 109 o 28 with each other. The structure formed is therefore very rigid. This makes diamond one of the hardest substances that are found naturally. All the physical properties of diamond come about due to its strong bonding.
Electricity is conducted in a crystal by electrons that are relatively free.
Electricity is conducted by electrons which can hop from one site to the other. Diamond is a good conductor of heat because the electrons in the bonds are shared and hence the heat can be dissipated easily. It shows a great potential for use in many fields. It's discoverers recently earned the 1996 Nobel Prize for Chemistry.