Is coconut shell good to produce charcoal for drawing?
Is coconut shell good to produce charcoal for drawing?


I am sure that will work just fine.
It does depend on the type of shape you want, as the structure of coconut shell is not optimal: it is naturally curved, making it hard - if not impossible - to get nice straight styluses out of it, and it might splinter more easily when exposed to high temperatures, because of the inherent tension.


  Does the material that we use to make the charcoal decide its tonal
  character?


It does, but not a lot. Different source materials have slight differences in pigmentation, texture, and strength. Generally, types of wood are used, of which willow and grapevine are the most popular types for drawing. You will notice larger differences between charcoal and charcoal pencils, than between types of wood.