That pattern is the Navajo Yeii Spirit. It's a spirit considered by the Navajo to be a mediator between man and his creator. Yeiis control natural forces, such as day and night, rain, wind, sun & others. A very exceptional kind of yeii is the Yei'bi'chai, grandparent spirit or "talking God" who can speak to man, teaching him how to live in harmony with all living things by following some simple rules of behavior to conserve and use well only the things he needs to survive. A symbol of the harmony achieved is the "Rainbow Man", a yeii commanding the rainbow, giving beauty to all those in harmony. It's a good necklace and is believed to bring positive energy and insight to the wearer. It was most popular amongst southwestern tourists in the late 50's - early 70's. Cheers.
I forgot.. it was made with an original handmade loom the size of a small 6" x 12". Sort of like a learning toy for children before they learn the large loom for blankets.