Pyrobitumen
![Figure 1. Classification System for Bitumens as Adapted from Abraham and Curiale](/Images/godic/202502/05/Figure_1_Abraham_Bitumen_Classification_System2347.jpg")
![Figure 2. Classification System for Solid Bitumens Adapted from Curiale using modern organic geochemical techniques.](/Images/godic/202502/05/Figure_2_Curiale_Solid_Bitumen_Classification_System2347.jpg")
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.