Hi Lotfy,
Like Spiral, I was also thinking along the lines of some kind of processed/resin/composite type material.
These faux-rhino 'amber' substitute hilt materials have to be a step in the right direction.
Anything is preferable to the loss of Rhinos.
I've often thought that with the explosion of cheap stone carving in China in recent years, semi precious stone hilts would be a fantastic and cost effective modern option.
Imagine a Khanjar with a jadeite or Nephrite hilt!