Bitumen is any naturally-occurring hydrocarbon, including in petroleum, but referring especially to the solid hydrocarbons such as wax, pitch, asphalt, and gilsonite. These are fusible and soluble in organic solvents, unlike the pyrobitumens.

 

Gilsonite

Gilsonite is a natural asphaltic bitumen found in veins near the Colorado/Utah border, in the Uinta Basin. Gilsonite is a lustrous black solid, used in paints and coating and insulating materials, and, more recently, converted to coke, gasoline, and gas.