What is "pyrobitumen"

n. An amorphous fossilized petroleum mineraloid.

Pyrobitumen is a type of solid, amorphous organic matter. Pyrobitumen is mostly insoluble in CS2 (and other organic solvents) as a result of molecular cross-linking which renders previously soluble organic matter (i.e., bitumen) insoluble., Not all solid bitumens are pyrobitumens, in that some solid bitumens (e.g., gilsonite) are soluble in common organic solvents, including CS2, dichloromethane, and benzene- methanol mixtures.