American Indian Jewelry by Gregory Schaaf
Over the past 150 years there have been thousands of Native American silversmiths. Identifying a hallmark is not always as easy as one would think. Native American hallmarks really did not become mainstream or commonplace until the early 1970’s during the turquoise jewelry revolution, we like to call it. Gregory Schaaf has probably written the most comprehensive book on Native American Hallmarks and is getting ready to release the third edition.
Alltribes Native American Jewelry Blog 