The Shulchan Aruch rules in OC 216:4 that there is a special blessing to say upon smelling "Afarsimon" oil. (The blessing is ברוך אתה ה' אלוקינו מלך העולם בּוֹרֵא שֶמֶן עָרֵב) The Mishna Berura there, quoting a number of Rishonim, explains that this is the ingredient of the Ketoret (incense burned in the Temple) known as Tzori which is likely the resin of Commiphora gileadensis.
Where can I get this substance?
Note: I found this product at the Temple Institute's gift shop. Is this the appropriate oil? Additionally, it is rather expensive. Maybe if someone can find just the correct oil for sale somewhere it will be at a more reasonable price.