what is stronger, bones (calcium) or carbon fiber?

I ask this question because in Pandorapedia says, "Bones composed of biologically produce carbon fiber composite."(banshee)

Bone is a composite of protein and hydroxyapatite crystals. It does not contain any carbon fibers, and it is not made of calcium.

http://en.wikipedia.org/wiki/Bone

http://en.wikipedia.org/wiki/Osseous_tissue

http://en.wikipedia.org/wiki/Hydroxyapatite

The crystals contain calcium ions, but they are not made OF calcium. Calcium is a soft gray metal.

http://en.wikipedia.org/wiki/Calcium