Petroleum is referred to as ‘black gold’.
Petroleum is a valuable fossil fuel which is used for running machineries, transport vehicles, airplanes, etc. It is also used to produce variety of products like diesel, kerosene, wax, lubricants, etc. Petroleum is a non renewable source of energy and its reserves are limited. Thus, petroleum is a very precious natural resource in the absence of which the human economic growth will suffer a huge loss.