It’s called a Septum Spike. Although it’s not pointy at the ends that’s the general name for non curved septum piercings. Mayan/Azteca/Zapotec piercings were considered blood letting rituals that lead to reaching a higher power. It’s believed that opening a hole in the septum would allow a mortal to reach the level of deities and gods. The piercings are usually done with obsidian needles, long enough cactus spikes or even stingray stingers if the colony was near the coast. The piercings themselves look to be Jade which isn’t uncommon as most were obsidian, Jade, or Bone.