Squid beak

Consider the squid beak, a material called chitin. Despite being sharp as a knife, chitin has no metal. It s made of CHON sugar and amino acid chains oxidized into a hard, flexible network. The insect eggshell is also hard and made of CHON elements. 

A. Miserez et al., The transition from stiff to compliant materials in squid beak. Science 319 (2008), 1816-19. 

Fox, j. D., Capadona, J. R, Marasco, P. D., and Rowan, S. J. (2013]. Bioinspired water-enhanced mechanical gradient nanocomposite films that mimic the architecture and properties of the squid beak, /. Am. Chem. Soc, 135,5167-5174. 

It is a low-density fatty compound produced in the whale s stomach and intestines in response to irritation, possibly from the passing of the hard, sharp beaks of squid, which are a major part of the whale s diet. 

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