Originally, jewelry was a symbol of wealth to the Navajo, used to trade for food and necessities during winter or in time of need. Since Mexican smiths (plateros) introduced Navajos to silver jewelry around 1850, Navajos have adopted and adapted the craft of making jewelry, first hammering coins with home-made tools, then pouring molten metal into carved stone molds, later adding set stones. A detailed history of Navajo jewelry-making can be found in Navajo Jewelry - A Legacy of Silver and Stone by Lois Essary Jacka.