bitumen

Involatile, tarry material, containing a mixture of hydrocarbons (mainly alkanes), that is the residue from the fractional distillation of crude oil (unrefined petroleum). Sometimes the term is restricted to a soft kind of pitch resembling asphalt.

Naturally occurring solid bitumen may have arisen as a residue from the evaporation of petroleum. If evaporation took place from a pool or lake of petroleum, the residue might form a pitch or asphalt lake, such as Pitch Lake in Trinidad. Bitumen was used in ancient times as a mortar, and by the Egyptians for embalming.