The Yei symbol is a frequently used pattern in Navajo rugs. In Navajo mythology, the Yei spirits mediated between the Great Spirit and humans (the name Yei derives from Yeibicheii, meaning the Holy People. Yeibichai rugs depict the ceremony in which dancers attempt to call the spirits). Yei spirits were believed to control natural elements such as the rain, snow, wind, and sun and to have healing powers.
In paintings and weavings depicting the Yei spirits, male deities are generally pictured with round heads and female deities with square heads. This distinction does not always hold true, though. In some cases, round heads are given to the more dominant spirits, regardless of gender. And there are other clues you can look for to determine whether a spirit is male or female. For instance, crooked lightning is often seen on the male spirits. Colors can also indicate gender, with black and yellow more associated with male figures and blue and white with females.
It can be considered sacrilegious to weave in the eyes and mouths of the Yeis, so these are often embroidered on after the rug is woven. In fact, these rugs were initially considered sacrilegious in general. Yeis were initially depicted in sandpaintings that would be erased at the end of the ceremony, so when weavings depicting the deities began to be made in the 1930s, there was some controversy over turning this ritual into a permanent and commercial art form. However, other Navajos argued that it was important to preserve the traditional art of sandpaintings through permanent sandpaintings and weavings.
We think that these beautiful weavings are a wonderful way to honor the spiritual beliefs of the Navajos and to preserve traditional symbols and myths. If you have any questions about specific Yei rugs, please contact Charley at firstname.lastname@example.org.
For a very detailed overview of the various Yei legends, see this very informative post from Twin Rocks Trading Post.