Sandarac comes from Tetraclinis articulata, a small, evergreen, cypress-like conifer in the family Cupressaceae and the sole species in its genus. Reaching heights of up to 15 metres and known in Arabic as "araar," the tree grows chiefly in the dry mountain regions of northwest Africa, above all across the Atlas ranges of southern Morocco and Algeria, with smaller populations on Malta and in southern Spain — the only place in Europe where a conifer of this family grows wild. Because of its drought tolerance, it has for some decades been planted deliberately in North Africa to reforest erosion-prone slopes. When the bark is cut, a clear, sticky resin seeps out and hardens in the air into small, translucent, pale-yellow tears, traditionally gathered by hand. The tree's scaly, reddish-brown bark and slender, often columnar growth make it unmistakable across its North African homeland.

The tree's dense, resin-rich root burl, traded in ancient Rome as "citrus" or thyine wood, ranked among antiquity's most coveted materials: wealthy Romans had its distinctive grain fashioned into tabletops, the "mensae citreae," some of which fetched higher prices than comparable pieces in silver or gold, and it is listed among Babylon's luxury goods as "thyine wood" in the Book of Revelation. The resin itself gained growing importance from the late Middle Ages onward under the name sandarac varnish, exported through the Moroccan port of Mogador, today's Essaouira, to Europe, where it remained one of the principal ingredients in furniture and instrument varnishes until shellac took over. This tree resin should not be confused with the identically named "sandaracha" of antiquity — a toxic, bright red arsenic sulfide mineral, today's realgar, which, despite sharing the name, has nothing to do with the conifer resin.

Burned as incense, sandarac releases a bright, warm, slightly fruity-resinous scent that sits close to frankincense but feels noticeably lighter and fresher. It works well as a base note in woody or oriental fragrance blends and is traditionally combined with other resins to extend and round out their scent. In North Africa it is still burned today in simpler form directly on charcoal, particularly in rural Morocco, where the tree still grows wild. In English-language trade the resin is often labelled "gum sandarac," and in everyday Moroccan life it still serves, alongside cedarwood and other local resins, as an ingredient in traditional incense blends known as bkhour.