I would guess that these may be palm wood, or even peeled moon-&-star seeds. (As from a Buddhist mala.)

However, if they are much harder than a woody seed, the material might be fossilized palm wood (or similar)—such as was exploited for making pumtek beads.

Nevertheless, I would not rule-out bone as a possible material. I can see some evidence of a crust on one bead that suggests bone—but could also be the remaining surface of a seed.

JDA.