Hmmm, this is indeed a thought inducing topic, now.
Two things that spring to my mind, though both of them are separated by timescale, I think.
One, was some reference I,d read, about embedding shards of flint into a growing sapling.....originally to provide a rather nasty war- cosh, but I suppose it could,ve been adapted to make a saw, of sorts.
Second, was a kind of verification of the power of abrasive grit, it was the prog where Egyptol,s demonstrated how it was poss to saw the stone that they used in the monuments..the medium, IIRC, was sand.
But, hang on, cos they had a bronze sheet... so that one wouldnt hold up.
Make it just the one, then.
Ceeg