BONES - Shock-absorbing 'goo' discovered in bone

New findings show that much of the mineral from which bone is made consists of 'goo' trapped between tiny crystals, allowing movement between them. It is this flexibility that stops bones from shattering. Latest research shows that the chemical citrate -- a by-product of natural cell metabolism -- is mixed with water to create a viscous fluid that is trapped between the nano-scale crystals that form our bones. This fluid allows enough movement, o ...

http://www.sciencedaily.com/releases/2014/03/140324154013.ht