Scientists have long known the basic chemical components of the pigment, which has a remarkable ability to resist age, acid, weathering, and even modern chemical solvents.
“Unlike a lot of natural pigments that may fade, [Maya blue] is very stable,” said Gary Feinman, curator of Mesoamerican anthropology at the Field Museum in Chicago, Illinois.
But the exact recipe, along with the tools the Maya used to create the pigment and the circumstances surrounding its use, were unknown.
Analyses revealed the incense was made of a copal, a tree sap whose smoke the Maya believed nourished the gods.
The pigment was the famed Maya blue, and the flecks were bits of a white clay mineral called palygorskite.
According to previous studies, Maya blue is made by fusing palygorskite with pigments from the leaves of the indigo plant.
But the two ingredients do not readily combine, and it was unknown how the Maya fused them.
Archaeologists had suspected that copal was important to the production of Maya blue, and the new findings seem to confirm that theory.
“Our study suggests that heat and copal incense likely were key elements used to fuse the two components together,” Feinman said.
from National Geographic
For a bit on red, read my blog post here.