Copal is a natural resin exuded from the bark of various tropical trees, primarily those native to Mesoamerica. The term derives from the Nahuatl word copalli, which translates to “incense” or “resinous gum.” This aromatic material has been harvested and utilized for thousands of years by indigenous cultures, such as the Maya and Aztec, where it served as a powerful spiritual and ceremonial tool. Unlike true tree sap, resin is a thicker, non-water-soluble fluid produced by the tree as a defense mechanism.
The Botanical Sources of Copal
The resin known as copal is predominantly sourced from trees belonging to the Burseraceae family, a group that also includes the sources of frankincense and myrrh. In Mexico and Central America, the genus Bursera is the most significant contributor, with species like Bursera bipinnata or Bursera copalifera being traditional sources. Other sources include Protium copal and some species of pine (Pinus) and the pea family (Fabaceae).
The tree produces this resin as a protective response to physical injury or insect attack. When the bark is damaged, the sticky fluid flows out to seal the wound, preventing pathogens and insects from entering the tree. Harvesters intentionally make small incisions in the bark to encourage the tree to exude the resin, which is then collected as it hardens into pale yellow or white lumps. This process requires careful management to ensure the health and continued productivity of the plant.
Traditional and Spiritual Significance
The spiritual use of copal has been central to Mesoamerican cultures since pre-Hispanic times, earning it the name “Blood of the Trees” from the Aztecs. Both the Maya and Aztec civilizations considered the resin sacred, utilizing it in religious ceremonies, healing practices, and as an offering to deities. The hardened resin was burned on hot charcoal, releasing a dense, sweet, and slightly citrusy smoke believed to facilitate a connection with the divine.
The resulting smoke, called pom by the Maya, was considered a purifying agent. Priests and healers used copal in rituals to cleanse spaces, objects, and individuals of negative energies, dispel illness, and remove spiritual impurities. It was also an integral part of funerary rites, burned at burial sites to honor the deceased and guide their spirits. This tradition continues today, as copal is a fixture in the Mexican celebration of Día de Muertos (Day of the Dead), where it is burned on altars to welcome the souls of loved ones. In contemporary indigenous communities, the resin is still used in sweat lodge ceremonies and rituals.
Modern Commercial Applications
While its spiritual use endures, copal also holds a place in several commercial and scientific applications. Historically, before the advent of modern synthetic materials, the resin was widely used in the production of high-quality varnishes and lacquers. Its natural hardness and ability to form a protective film made it a valued ingredient for finishing furniture and other wooden objects. Today, it is also polished and shaped for use in jewelry, primarily due to its warm color and the relative ease with which it can be worked.
The resin also serves a specific purpose in geology and paleontology, where it is defined by its age and state of fossilization. Scientifically, copal is considered a sub-fossilized resin, typically ranging from a few hundred to tens of thousands of years old. This relatively young material is chemically unstable and softer than true amber, which has undergone complete polymerization and is at least 100,000 years old, often millions. Because of its age, copal is frequently found with remarkably preserved insect and plant inclusions, providing paleontologists with valuable glimpses into more recent ancient ecosystems. The application of solvents like acetone can easily distinguish copal from amber, as the former will become tacky, a simple test that reflects its incomplete molecular hardening.