I haven't used tag "magic" because while the process is magical, I am interested in resulting material, which is itself completely unmagical and follows physical laws of our world.
So, I have a problem. My magic civilizations are due to reasons magical unable to use most metals in pure form or as alloys for most typical uses, only being able to use their compounds[read rocks]. Instead, some of them are able to refine organic material, and for example alter its shape or join it together similarly to how smiths can smelt. They mostly use bones and wood as materials for their weapons. I already have wood covered(found out about densified wood), now I need to focus on bones.
While metalwork is not in use, they're able to alter the material to some extent. While the process of alteration is magical, the result of the process isn't. The material simply changes its structure or content, and there is no sustained magical effect after the process is over. They can't(at least not yet) do anything as drastic as produce nano materials, but they can remove things that were useful for a bone in a living organism, but are bad for bone as a material.
List of all restrictions:
they can remove things that were useful for a bone in a living organism, but are bad for bone as a material(marrow, microholes for blood flow, etc.).
they can alter composition by removing material to make the quality better (it is possible to remove some of the calcium or colagen, but it's not possible to replace them with something else like metals).
they can introduce new organic materials(not in the meaning of organic chemistry, but in meaning recently originating from organism, such as shells, teeth or recently cut wood, but not anything that was abandoned by the organism years ago) to the bones. (Yeah, I've read about limpet teeth and I do plan to use that, but only for extraordinarily expensive weapons for nobles, as it is a rare material in my setting, but I also need standard weapons for common soldiers)
So, How much can bones be improved as a weapon/armour material under these restrictions?