Recently, a Spanish group of chemists discovered a new pigment in the famous Maya Blue paint.
Known for its resiliency to harsh environmental conditions and vibrant color, Maya Blue has remained more of a mystery than not for centuries. Through earlier chemical analysis, researchers discovered the two main components of the paint – indigo (pigment) and palygorskite (type of clay).
Finding these two ingredients weren’t hard. Researchers and chemists knew there had to be at least two ingredients – 1) a source of color and 2) a thick base that the color could attach itself to. They found these easy enough, but they knew there was something missing – a secret third ingredient. It’s speculated that this ingredient is responsible for the paint’s durability and sticking qualities.
But this isn’t what the Spanish researchers found. They did, however, discover something equally impressive.
Dehydroindigo – a yellow dye.
The reason this is impressive is because Maya Blue was thought to only contain one dye for centuries. Indigo and Maya Blue were used synonymously by researchers and the public when, in reality, they had different chemical makeups.
Speaking on the findings, Antonio Doménech, one of the researchers from the University of Valencia said, “We detected a second pigment in the samples, dehydroindigo, which must have formed through oxidation of the indigo when it underwent exposure to the heat that is required to prepare Maya Blue.”
Doménech also said that he believed the Mayans played with the heat temperature during production to make the paint greener or bluer. The more heat added during the baking process, the greener the paint would become from the higher levels of dehydroindigo. After the chemical analysis, he made a conclusion that made sense of Mayan Blue’s unique blue color.
“Indigo is blue and dehydroindigo is yellow, therefore the presence of both pigments in variable proportions would justify the more or less greenish tone of Maya Blue,” Doménech explained.
Although the third ingredient of Maya Blue still remains a mystery, the Spanish researchers discovered something equally enlightening, dehydroindigo: a previously unknown fourth ingredient. Through chemical analysis, though, Doménech and his colleagues are determined to discover the third ingredient in Maya Blue – an ingredient that has remained a mystery since the fall of the Mayans.