The chemical composition of frankincense (olibanum/libanum) has been studied for over sixty years. It is a natural oleo-gum-resin composed of primarily alcohol-soluble resins, and smaller amounts of essential oils and water-soluble gums. A number of reviewers have listed over 157 components identified in the oil and resin fractions. The long list of compounds identified includes complex mixtures of mono-, di-, and triterpenoids. (Toste, Zarins and Folsom 1996). Chemical analysis of frankincense sap collected in Dhofar from various locales clearly suggests that the chemical signature varies considerably. Archaeological frankincense samples could thus theoretically be matched against source areas once South Arabia and northern Somalia are properly sourced (see e.g. Provance 1986). In this regard, frankincense sap could parallel the earlier work on obsidians. (see above). Similar chemical analysis could also be carried out on various myrrhs (Zhu et al 2001) and terebinth (see ref).