get suit to the surrounding. believe we’ll find a way solving.
Fire/ is something such high dvelope today. actually i mean knife…
why should we force on it?
it s hard work making knife or.?
hunting elements bones…similiars teeth its kinda violent… necesaary.??
metal… hot hard work? stone? is it possible… is it sharp for our cut thing we wanna have?
is there something else… ?
Metal would be extremely time consuming, the metal needs to be heated to the correct temp. then beaten into shape then reheated and quenched. Stone can work, Obsidian is a good example of a stone with incredibly sharp edges, but knives made from Obsidian seem prone to cracking.
Stone flakes and naturally sharp oyster cut just fine. Fancy stone knives look nice but I mostly see no point in making them when you usually just need a flake to do the job (except for projectile tips or maybe axe and adze heads). Hell sometimes a sharp stick does the job just as well as a metal blade would (digging stick vs metal trowel) and requires barely any work to make the tool.
Hey streunner, your English is getting better! 
As for bone knifes, if done right, they can be quite sharp, but take a long time to sand down properly.
Obsidian makes a very sharp blade, but like any very sharp blade it is also fragile and will chip. However, other stones, such as malachite (sp), can be flaked sharp enough to slice through meat, but are dull enough not to chip as easily.
You can also grind down sedimentary rocks, such as greenstone, using sand to a very sharp edge. You have to be careful of the angle though, metal gives you a much more forgiving edge.