Conventional C-13 and H-1 nuclear magnetic resonance (NMR) spectra and C-13 inverse BIRD correlation nuclear magnetic resonance spectra of chloroform extracts of resinites from different sources in the Latrobe Valley, Australia have been obtained. At least three types of exocyclic diterpenoid based alkenes were observed and the type of alkene present was found to be variable. Comparison of solution NMR spectra of Yallourn resinite extract with solid state spectra of the whole resinite showed that exocyclic alkenes were less extractable than the other alkenes present. This suggests that molecules containing exocyclic alkenes compose a greater part of the polymerised macromolecules than the other alkenes which are more soluble. Whole resinite samples were also methylated and studied by NMR and laser ablation Fourier transform ion cyclotron resonance (FTICR). Apart from evidence for C20H29O2 ions from diterpenoid subunits, ions from macromolecules with a diterpenoid polymeric structure with an additional 16 atomic mass units were detected. It is possible that there are oxidised materials of the same diterpenoid subunits.