Nice work on this mini. I too like the diamonds and whats you've done with them. As for the bone I reckon an extreme highlight with a little white mixed in and perhaps some highlights on the blade tip would really make it stand out. You should be very proud of your painting skills.
I like what you have done with this min - especially the diamonds are really good. However, I think the shadows on the bonepart (especially the spear) are too dark - a lighter brown (e.g. Bubonic brown) would probably make it smoother.