It is the only element of group of the periodic table which occurs in the free states as in diamond, graphite, and coal.
In the combined state, it is widely distributed in nature.
It is an important constituent of all organic compounds.
The purest form of carbon:
The purest form of carbon is diamond.
In diamond, each carbon atom is hybridized. It is bonded tetrahedral to four other carbon atoms by strong covalent bonds. Thus, it has a three-dimensional network of strong covalent bonds in which the bond length is and each bond angle is .
The composition of a diamond is homogenous, making it the purest form of carbon.