Copal, the Blood of Trees - Sacred Ancient Maya and Aztec Incense

The Smoky Sweetness of Incense Used in Aztec and Maya Rituals

Copal Crystals in a Cast Iron Container Burn on a Grate
Copal Crystals in a Cast Iron Container Burn on a Grate. stereogab

Copal is the name of a smoky sweet incense derived from tree sap that was used by ancient North American Aztec and Maya cultures in a range of ritual ceremonies. The incense was made from the fresh sap of trees: copal sap is one of numerous resinous oils which exude and are harvested from the bark of certain trees or shrubs around the world.

Although the word "copal" derives from the Nahuatl (Aztec) word "copalli", copal is today used generically to refer to gums and resins from trees throughout the world.

Copal made its way into English by way of a 1577 English translation of the Native American pharmacological traditions compiled by the 16th century Spanish physician Nicolás Monardes. This article speaks primarily to North American copals; see Tree Resins and Archaeology for further information about other copals.

Using Copal

A number of hardened tree resins were used as aromatic incense by most pre-Columbian Mesoamerican cultures, for a variety of rituals: according to Stoss resins were considered the "blood of trees". The versatile resin was also used as a binder for pigments used on Maya murals; in the hispanic period, copal was used in the lost wax technique of making jewelry. The 16th century Spanish friar Bernardino de Sahagun reported that the Aztec people used copal as makeup, adhesives for masks, and in dentistry where copal was mixed with calcium phosphate to affix precious stones to teeth.

Copal was also used as a chewing gum, and a medicine for various ailments.

A handful of studies (see Lona, Lucero-Gomez et al., Gifford, Vanenabeele et al. listed below) have been conducted on the extensive materials recovered from the Great Temple (Templo Mayor) at the Aztec capital city of Tenochtitlan.

These artifacts were found in stone boxes beneath the buildings, or directly buried as part of construction fill. Among the copal-associated artifacts were figurines, lumps and bars of copal, and ceremonial knives with copal adhesive at the base.

Lona (2012) examined 300 pieces of copal found at the Templo Mayor, including about 80 figurines. She discovered they had been made with an inner core of copal, which was then covered with a layer of stucco then formed by a double-sided mold. The figurines were then painted and give paper garments or flags.

Bursera Species

Most often, American copals refers to resin from various members of the tropical Burseraceae (torchwood) family. Other resin-bearing plants that are known or suspected of being American sources of copal include Hymenaea, a legume; Pinus (pines or pinyons); Jatropha (spurges); and Rhus (sumac).

There are between 35-100 members of the Burseraceae family in the Americas. Bursera are highly resinous and release a characteristic pine-lemony odor when a leaf or branch is broken. Various Bursera members which are known or suspected to have been used in Maya and Aztec communities are B. bipinnata, B. stenophylla, B. simaruba, B. grandifola, B. excelsa, B. laxiflora, B. penicillata and B. copalifera.

All of these generate resins suitable for copal. Gas-chromatography has been used to attempt to resolve the identification issue, but it has proven difficult to identify the specific tree from an archaeological deposit because the resins have very similar molecular compositions. After an extensive study on examples from the Templo Mayor, Lucero-Gomez et al. believe they have identified an Aztec preference for B. bipinnata and/or B. stenophylla.

Historic references to copal use include the Mayan book the Popol Vuh, which includes a long passage describing how the sun, moon and stars arrived on earth bringing copal with them. This document also makes it clear that the Maya collected distinct types of resin from different plants; Sahagun has also written that Aztec copal also came from a variety of palnts.

Varieties of Copal

Several varieties of copal are recognized in historic and modern markets in Central and North America, partly based on what plant the resin came from, but also on the harvesting and processing method used.

Wild copal, also called gum or stone copal, exudes naturally as a result of invasive insect attacks through the bark of the tree, as greyish drops which serve to plug the holes.

Harvesters use a curved knife to cut or scrape the fresh drops off the bark, which are combined into a soft round glob. Other layers of gum are added until the desired shape and size is achieved. The external layer is then smoothed or polished and subjected to heat to enhance the adhesive properties and consolidate the mass (described in Lucero-Gomez et al).

White Copal

White copal (copal blanco or "the saint", "penca" or agave leaf copal) is obtained by making diagonal cuts through the bark into the trunk or branches of a tree. The milky sap flows along the channel of the cuts down the tree to a container (an agave or aloe leaf or a gourd) placed at the foot. The sap hardens in the shape of its container, and brought to market without further processing. According to Hispanic records, this form of the resin was used as Aztec tribute, and transported from the outlying subject provinces to Tenochtitlan.

Every 80 days, so it was said, 8,000 packages of wild copal wrapped in maize leaves and 400 baskets of white copal in bars were brought into Tenochtitlan as tribute (described in Lona 2012).

Copal oro, reported in Mesoamerican markets by Case et al. in 2003, is resin which is obtained by the complete removal of the bark of a tree; and copal negro is said to be obtained from beating the bark.

Lacandón Maya

According to Stross, the Lacandón Maya made copal from the pitch pine tree (Pinus pseudostrobus), using the "white copal" method described above, and then the bars were pounded into a thick paste and stored in large gourd bowls to be burned as incense as food for the gods.

The Lacandón also fashioned nodules, shaped like maize ears and kernels: some evidence suggests copal incense was spiritually connected to maize for Maya groups. Some of the copal offerings from Chichen Itza's sacred well were painted greenish blue and embedded pieces of worked jade.

  • Read about the discovery of a copal discovery at Chichen Itza
  • See Stross (an open access study) for detailed information about who used what copal.

Case et al. describe a Maya Ch'orti method of processing the copal as follows. Collect the gum, let it dry for a day and then boil it with water for some eight to ten hours. The gum rises to the surface and is skimmed off with a gourd dipper. The gum is placed into cold water to harden somewhat, then shaped into round, elongated pellets about the size of a cigar, or into disks about the size of a small coin. After it becomes hard and brittle, the copal is wrapped into corn shucks and either used or sold in the market.


This article is a part of the guide to the Tree Resins and Archaeology, and the Dictionary of Archaeology.

Case RJ, Tucker AO, Maciarello MJ, and Wheeler KA. 2003. Chemistry and ethnobotany of commercial incense copals copal blanco, copal oro, and copal negro, of North America. Economic Botany 57(2):189-202. doi: 10.1663/0013-0001(2003)057[0189:CAEOCI]2.0.CO;2

Gifford EK. 2013. Organic and Inorganic Chemical Characterization of Artifacts from the Emanuel Point Shipwrecks. Pensacola: University of West Florida.

Lona NV. 2012. Objects made of copal resin: a radiological analysis. Boletín de la Sociedad Geológica Mexicana 64(2):207-213.

Lucero-Gómez P, Mathe C, Vieillescazes C, Bucio L, Belio I, and Vega R. 2014. Analysis of Mexican reference standards for Bursera spp. resins by Gas Chromatography–Mass Spectrometry and application to archaeological objects.

Journal of Archaeological Science 41(0):679-690. doi: 10.1016/j.jas.2013.07.021

Penney D, Wadsworth C, Fox G, Kennedy SL, Preziosi RF, and Brown TA. 2013. Absence of ancient DNA in sub-fossil insect inclusions preserved in ‘anthropocene’ Colombian copal. PLoS ONE 8(9):e73150. doi: 10.1371/journal.pone.0073150

Stross B. 1997. Mesoamerican copal resins. U-Mut Maya 6:177-186.

Vandenabeele P, Grimaldi DM, Edwards HGM, and Moens L. 2003. Raman spectroscopy of different types of Mexican copal resins. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 59(10):2221-2229. doi: 10.1016/S1386-1425(03)00066-0