Horn, or hoof?

[Richard G]

I have in my possession an ass's hoof that has been mounted as an ashtray as a souvenir from the WW1 campaigns in Palestine. The hoof itself is a light olive fibrous structure. I also have a jambiya with a hilt of a remarkably similar material which I think most collectors might assume to be rhino horn, because if it's not buffallo or wood, and is fibrous and transmits light then that is what a jambiya hilt should be. Never, in many years of collecting, can I remember the hilt of a jambiya, or indeed any weapon, being described as from the hoof of any animal. Is this simply because It did not happen? or because we assume it did not happen?
I ask these question because I do not know; but, for example, are the toes and hooves of rhino, elephant, camel, buffalo etc. suitable material for the hilt of a jambiya? Were they ever used as such, even if surreptitously?
Regards
Richard