on ivory, feathers and animal bits as ornamentation

"The Bull Leaper" 15th-century ivory figurine from the palace of Knossos, Crete

I worry about offending people, which is the reason I hesitate to use anything that even looks like old ivory. I mean, really, to say that it's pre-ban ivory doesn't make it okay; an elephant killed for its pieces is still a murdered elephant. Unless you've been desecrating an elephant graveyard or finding the actual skeleton itself. I guess if I'm walking the savannah and trip over a tusk, I could use that tusk without guilt.

I've sometimes questioned the acceptability of using of items depicting circus elephants. I don't think most captive, trained animals are happy.

And what about bones? Are they okay? I purchased some old ivory piano keys, intending to try my hand at scrimshaw.

Also, I'm reluctant to incorporate feathers in my pieces. Where are they coming from? I did find an already road-killed pheasant on a trip a couple of years ago, so I can use its feathers without guilt.