#gilsonite
- Asphaltite — A natural variety of solid bitumen, black or dark brown in color, with a silky or vitreous luster and conchoidal fracture, formed through the natural oxidation and polymerization of petroleum within the layers of the earth's crust. This hydrocarbon mineral has a high melting point (between 110 and 200 degrees Celsius) and is industrially utilized in manufacturing insulating varnishes, special paints, plastics, and high-performance electrical insulations.