I'm just not thinking broadly enough as to materials for handgun grips. I've always thought wood, plastic, rubber, and maybe ivory was about all that was needed.
Here are a couple of other suggestions:
1) pronghorn leg bone, because they're supposed to be extremely strong.
2) pork roast bone, because I've gone an old pork roast bone in the back yard.
3) coproliths (fossilized dinosaur crap)
4) amber with bugs in it
5) acrylic with semi-precious stones cast into it.
6) pumice, for those guys who like to have the skin ripped off their palms when their magnum recoils.
The possibilities are endless