Would fire blackening really made wood, or bone for that matter, any harder or more useful? I wouldn't think so, but I see it a lot in game.
From what I know- which remains to be very little- blackening may in fact provide a somewhat harder surface.
Think about it.
Firstly, would these people develop a useless practice like that? I'm sure not everyone could just grab a stick and blacken it just enough.. just so much that it doesn't burn into something weak and useless.
Someone'd have to have experience, and the method to do that sort of thing'd have to be developed enough to be useful. Cultures' notions of what works and what doesn't aren't -all- going to be unfounded and rediculous, as everything has its roots and base reasons- ie. murder, incest, and the like. All are based upon simple facts that they're not good for people and their development, so cultures just place taboos on them.
I'm getting way off topic.. and I could be wrong about the fire-blackening thing at that.
I heard once from a blacksmith at one of those museum type places that the reason for blackening works like this:
The outer surface goes through a rapid loss of moisture and seals the inner moisture in. Its kinda like a really piss poor protective coat that keeps the inside protected and the outside hardened. The one time I Made arrows IRL they were all wood tips and I could shoot the balckened ones into the gorund three or four times before they would bend like the untreated ones. So It definately does something.
also its not like blackening like burning it. Its a skillful thing...
fire-blackening/burning it will burn out oxygen pore and pockets in the grain of metal or wood, or bone, making it sturdier I guess. Kinda like pottery im guessing. Where hard/dry clay is fire-hardened to make it even stronger.
Nod, works well on wood.
Though if you attempted to fire harden/blacken bone in real life, you would destroy it because heat breaks down the bonds in calcium then causes it to bind (becomes a powder).
But Maybe Zalanthian bones are made of something else.
On wood, it dries the material and hardens the resin inside. It only chars a little, and is sharpened to the final edge after that.
On bone, I have seen real life references of fire-hardened bone, but I'm not sure how it's done. X-D is probably right, since I can't find any explaination of it anywhere.
Metal is far more complicated. Heating and cooling at different rates changes the structure instead of the composition.
And hot rocks are good only for playing games, I think.