I've made one from raw slate and an antler about 7" long. Another one I've made was from a turtle shell. I drilled a hole in the top and inserted a 3-4" piece of hickory, then used a piece of chert to scratch the the piece of hickory. The shell serves as a sound box, and by raising or lowering the hickory stick, you can get different pitches from it. Bulky, but its neat. I prefer the slat and antler though.
Pare-