Wiktionary
n. (context organic chemistry English) Any of the dark organic constituents of crude oils and bitumen that are soluble in aromatic solvents but not in aliphatic ones; they are polycyclic aromatic compounds (composed of fused benzene rings) with aliphatic side chains
Wikipedia
Asphaltenes are molecular substances that are found in crude oil, along with resins, aromatic hydrocarbons, and saturates (i.e. saturated hydrocarbons such as alkanes). The word "asphaltene" was coined by Boussingault in 1837 when he noticed that the distillation residue of some bitumens had asphalt-like properties. Asphaltenes in the form of asphalt or bitumen products from oil refineries are used as paving materials on roads, shingles for roofs, and waterproof coatings on building foundations.