Carbon is a chemical element with the symbol C and atomic number 6 . Carbon is capable of forming many allotropes(structurally different forms of the same element). Carbon exists in two different forms i.e., crystalline and amorphous forms. i. Crystalline forms: Diamond: In diamond, each atom of carbon of the given crystal unit is surrounded by four other carbon atoms, which are joined by covalent bonds, such that they form a regular tetrahedron. Diamond is the hardest naturally occurring substance. Graphite: In graphite, atoms of a single crystal are arranged in a hexagonal ring in a single plane. The bonds between the carbon atoms of two single crystals in the parallel planes are weak. This is why graphite is soft and can be used as a lubricant. Buckminsterfullerene is a cluster of sixty carbon atoms arranged in the form of a football. It is named after the American architect Buckminster Fuller. Since it contains sixty carbon atoms, its chemical formula is C 60 . ii. Amorphous/Non-crystalline forms: Charcoal: It is produced from the bones of animals, combustion of wood, etc. Coal: It is formed by the decomposition of dead remains of plants when they got buried in the land owing to the high temperature and pressure conditions present there.