While spending some time crafting, I had an idea about crafting spearheads and arrowheads...
When lithic peoples made things like these, they would shape a "core" from which they would work. This core would be good for maybe 5-6 lithic points, then the last part could be used to make a burin (stone tool for making holes, like an awl).
How about "craft core" as a command, creating an object from which arrowheads/spearheads can be crafted?
The object "obsidian core" (or whatever material we're working with) could then be used to make a number of points (or fail to make). This would allow a "chunk of obsidian" to make a series of arrowheads or spearheads.
Morrolan
You can already do that with obsidian?
Stonecraft it.
I seem to recall trying "craft stone" on a whim, and getting an option to try to craft a big chunk of stone into little chunks of stone, and then being able to craft little chunks of stone into shards of stone. Breaking rocks into smaller rocks isn't highly skilled work, so it makes sense that you could attempt it without the stonecrafting skill. You may ruin parts of the stone if you are just whacking it with a bigger stone to break it into smaller pieces, but you should get a few usuable shards out of it.
AC