A long (geological) time ago, water circulated underground in a few places on what was to become the Zuni Reservation. The water flowed through some limestone deposits, dissolving some of the minerals. These minerals dripped into some of the underground cavities and formed travertine deposits. Later, water containing the limestone minerals flowed into the remaining cavities. Calcite crystals formed as the minerals precipitated out of solution. These processes are similar to those that formed septarian nodules in Utah.
In more recent times, erosion exposed some of these mineral formations. Felino and Orin found one of these exposed deposits while acting as Zuni hunting guides. They returned to pick up these found rocks. Only a small number of specimens have the travertine and calcite deposits inside. They break open the samples, carrying only the better samples back to Zuni Pueblo for carving.
The choice of animal is up to the carver, who carves whatever likeness he sees in the raw stone.