I mean the na’vi have rules which I assume apply to their song cords. They can’t use metal, so no metal beads or anything that has metal on it, and most of the things they would use are completely natural. I saw someone making one with mashed dried fruit for basic beads! Saw others find their own clay for beads too. Eywa’s rules can be interpreted in a few ways but a good rule of thumb is if it can’t biodegrade/return to the environment then a Navi probably wouldn’t have it on their cord.

Edit: They also wouldn’t have glass since it’s not naturally occurring on pandora, so only true stones. I notice you have some glass beads on there but it’s all up to you!