A variety of sophisticated analytical tests have been run on Gilsonite to characterize its unique properties. For reference, the test methods include vacuum thermal gravimetric analysis (TGA), nuclear magnetic resonance (NMR), Fourier transform infrared spectrometry (FTIR), vapor pressure osometry (VPO), high performance liquid chromatography (HPLC), rapid capillary gas chromatography (RCAP), and several fractionation techniques. H/C ratios and NMR analysis indicate the presence of a significant aromatic fraction. Most of the aromatics exist in stable, conjugated systems, probably porphyrin-like structures that relate to the geologic source of the product. The remainder of the product consists of long, paraffinic chains.
A very unique feature of Gilsonite is its high nitrogen content, which is present mainly as pyrrole, pyridine, and amide functional groups. Phenolic and carbonyl groups are also present. The low oxygen content relative to nitrogen suggests that much of the nitrogen has basic functionality. This probably accounts for Gilsonite's special surface wetting properties and resistance to free radical oxidation.
The chemical differences are small between Gilsonite grades, with only subtle variations in average molecular weight and asphaltene/resin-oil ratios.
Gilsonite can be dissolved in organic solvents such as carbon disulfide, toluene and tetrachlorethylene while being insoluble in water and alcohol solvents. Pure Gilsonite contains 70-80% carbon, 15% hydrogen, 5% nitrogen, oxygen, sulfur, metal elements as well as 15-30% volatile organic compounds. The high content of carbon and nitrogen causes specific properties of Gilsonite. The average molecular weight of Gilsonite is 3000 which is higher than other asphalt products and synthetic resins. In terms of composition, it is a quasi-polymer compound.