An interesting thing to do art work on. But of course there has been art don on Elephant tusks, so should not be surprised something would be done on antlers.
Some good designs there, do you us some sort of small drill bit and use it like a pen? also the surface looks nice and smooth too. You must have some nice tools and good presition. I would imagine working with the antlers would be hard till you break it down to more manageable parts till you can even start on these pendants.