It has been noted by many people who have had the privilege of exploring Mayan ruins that there is a stunning blue color that has been preserved amazing well for centuries. Considering the tropical jungle is quite a hostile environment, the tenacity of this “paint” is remarkable. It had been suggested that this “paint” was made by mixing indigo dye with clay, but this did not explain its special characteristics. Recent work by Miguel José-Yacamán at the National University of Mexico and colleagues has revealed what is special about this material, which is called Maya blue paint. They collected specimens in Mexico at archeologic sites known as Jaina Island and Palenque.