There are federal laws governing the commercial trade for Native American jewelry, with specific info on what can be sold as such. Penalties apply for violating these laws.
[Buying American Indian Arts and Crafts | Consumer Advice]
https://www.doi.gov/iacb/act
If you’re interested in learning about Native American Southwest jewelry, you may want to read the many books on the subject. And of course read the numerous threads with valuable info on this site.
Thread:
https://forum.turquoisepeople.com/t/books-on-southwest-indian-jewelry/3871