Graphite and diamonds are the allotropes of carbon. Graphite conducts electricity but not diamond. Why so ?

Explanation

In diamond each carbon atom of a single crystal is surrounded by four other carbon atoms by covalent bonds such that the form four corners of a regular tetrahedron. Because of our covalent bonds with each car on atom there is no free electron available. Due to the npn availability of free electrons with in crystalline structure, diamond acts as a bad conductor of electricity.
In graph, every carbon atom in a single crystal is covalently bonded to three carbon atoms. As each carbon atom has four valence electrons one valence is left free for each carbon atom.These free electrons can be easily made to flow within the crystalline structure of graphite by applying electric potential. Thus graphite is a good conductor of electricity