Chaka wearing neclace
Un-gou'aulded Unas who continue to live on the original Goa'uld homeworld of P3X-888, which is also the original Unas homeworld, protect themselves from the more-primitive goa'uld that still inhabit the waters there by creating and wearing bone necklaces. These do not serve as complete protection from the goa'uld symbiotes which swim in the rivers and lakes of the planet, but do offer some protection. The Unas are quite aware of this, and so remain very wary and alert if they must approach the water. (SG1: "The First Ones")