Bitumen is a mixture of dense, sticky, viscous organic liquids, which is mainly composed of polycyclic aromatic hydrocarbons, obtained naturally from crude oil distillation.
Naturally occurring or crude bitumen is a sticky, tar-like form of petroleum which is so thick and heavy that it must be heated or diluted before it can flow.
At room temperature, it is much like cold ooze. Refined Bitumen is the residual (bottom) fraction obtained by fractional distillation of crude oil. It is the heaviest fraction and the one with the highest boiling point of 525 °C (977 °F).