Necklace designed by primitive Unas to prevent Goa'uld symbiotes from burrowing into the back of their necks and taking them as hosts. The necklaces are constructed of strong bones and therefore remain sturdy. They are of personal value to the owner, and it is not uncommon for them to be used as items of trade.
The First Ones - Daniel meets Chaka on P3X-888, and realizes that the native Unas have constructed bone necklaces to help protect them from Goa'uld penetration.
Beast of Burden - Chaka is captured by humans and taken to another planet, where he helps to free the local Unas population from slavery.
Enemy Mine - Chaka offers his necklace in trade with Kor Asek, leader of an Unas tribe on P3X-403, as part of peace negotiations.