Here are some of the tests I did for the bone material. For now, I used an image of a sponge (different for what I used for my sponge texture), but I'm going to look at other image files I could use instead but I thought it was a reasonable start. I played around with some subsurface scattering to give it a more organic feel. Again I didn't want to be too literal with the portrayal of vertebrae, so I was allowing the material to be more bone-like than bone itself. Out of these I prefer 007 and 009 but I'm not completely satisfied with these yet so I will continue to work on them.