This mutation happened a million years again under the influence of bacteria. This bacterial decomposition of petroleum resulted in reduce content of saturated hydrocarbons, mainly n-alkalenes and light oil which became heavier and more viscous, taking the form of asphalt. It is natural product a bituminous limestone in which carbonate of lime and pure natural asphalt are most intimately combined by natural agency. It is as bitumen created in the process of crude oil processing. It is native substances of variable color, hardness and volatility, composed principally of the elements carbon and hydrogen and sometimes associated with mineral matter and essentially free of gas. It is largely soluble in carbon disulfide. It is actually semisolid or solid mixture of hydrocarbon and as much as 50% heterocyclic compounds constituted largely of carbon and hydrogen but having substitutes of sulfur, oxygen, nitrogen and trde metal ,specially iron, nickel and vanadium in the carbon network.