Definitely an art within the general art of guitar making. I mentioned having patience earlier but I don't think I have the level of patience you do to go through all the various time consuming processes you put into making your guits. I've got a lot of respect for that. It's one thing to fix them or even slap components together but to plot them out from start to finish and hand make most of the parts... that's true art.
 
As far as nuts... I think the blank I have is simple cow femur. Very hard. I'd imagine antler is a lot easier to work with and likely less prone to shatter. Not that I whip my guitars around like a fool anymore but still... a little give if I sent one for a faceplant on the floor would be nice.

The place I got this blank from had other blank material available (it was boutique type shop that has since closed). I think deer antler might have been in there but not moose. The cow femur was much cheaper though and it was meant for an old beater guitar anyway (which I no longer have...) that I had completely destroyed the nut on. I was not very nice to my guitars back then.