The two plaster masks in situ were facing the wall with the snouts protruding put the other side, so they couldn’t be seen from this angle. They were painted with five colors-green, black, red, gray and white. In an attempt to find the sources of the colors, we enlisted the aid of four scientists from Lakehead University, Thunder Bay, Ontario. WE certainly appreciate the efforts of Philip Fralick, Stephen Kissin, Joe Stewart, and Neil Weir. The different local pigments sources that were analyzed include red and gray clays, a piece of sandstone with copper traces that was found on the floor with the masks, some shales, also from the room floor, and coal deposits that outcrop a few miles west of the pueblo near Madrid.
The scientists who published the results of their investigation the Journal of Archaeological Science (2000) reported that the green color came from oxidized copper minerals such as malachite, azurite, and chrysocolla, which are found locally. The red color came from an iron-bearing mineral, probably hematite. In some cases, the red paint was mixed with finely crushed selenite to lighten its color. It is possible that plant juices were used as binding agents for the red paint.
The black color could have been made from either charcoal or carbonaceous shale, probably the former. The locally found gray clay was surprisingly ruled out as a source for the gray color on the masks. Instead, it was found to be a mixture of amber-tinted gypsum, a small amount of carbonaceous material, and white gypsum.
The masks were constructed by first building a cylinder of bulrush that was formed around a wooden hoop foundation.