I tend to draw a lot of tribal-themed stuff, yet I hadn't actually looked at any real stone/bone weapons for reference or inspiration. That bugged me, so I doodled a few.

The long one is made from the forelimb of a largeish land animal. The one on the right is stone bladed with a bone handle.

The one in the middle looks nice but I don't think bone or stone could be shaped that way... perhaps it's very very hard wood?