Unfortunately, this necklace is not Native American. The style of the necklace, with two “hanging strands” is not typical of NA jewelry. The silver beads are also not Native American, they are machine made. This necklace was probably imported, or is a southwestern “tourist piece.”
The beads look like they are made of onyx here. With that being said, these bears and beads would actually be very easy to replace due to the material and the fact I belive they are imported. If this piece is significant to you, than by all means attempt to repair it! That’s what matters most.
A while ago I wrote a post about fetish necklaces I think you might find useful.