Call them fetishes, charms, amulets, talismans, or simply good luck pieces, virtually every culture has them.
Fetish is a poor English equivalent for a concept, which has a different name and even a somewhat different meaning in each language of the Native American tribes that use such objects. Even in a single culture, such as Zuni, there are many different categories of fetishes.
Zuni religious tradition records a legend about how certain fetishes came to be. The basic version begins when the world was wet and muddy. This unstable earth had to be dried and hardened. The task was done by the twin sons of the Sun Father. They shot lighting to the four corners of the world. In the process the animals of prey that threatened the existence of humans were petrified into stone.
Simple possession of a fetish is insufficient to provide the owner with aid or protection. At the very least there are prayers to intone or an offering to be made.
Fetishes may be given offerings to solicit or encourage their help, but they are not prayed to. Prayer in most Indian cultures is directed towards a deity or deities. When offered correctly, down to the tiniest detail and with a clear heart, prayer compels the gods to answer. It is not a supplication. Interestingly, many of the recorded ritual prayers of the Native American peoples are meant to bring blessings to all, not just the person uttering the prayer. **
**Source for Fetishes Description used with permission. SPIRIT IN THE STONE by Mark Bahti, Published by Treasure Chest Books, Tucson, AZ.