The jaws, leg claws, stings and other tools of a large fraction of arthropods, some worms and members of other phyla, contain extraordinary amounts of heavy metals or bromine (e.g. Zn, Mn, Fe, Cu, and Br), which we term heavy-element biomaterials (HEBs). Although the concentrations reach 25% of dry mass, these materials do not contain an ordered biomineral, like calcified tissues. In fact, X-ray absorption spectroscopy suggests that, in the Zn-version of these biomaterials, the spacing between even the closest Zn atoms is irregular. We propose to use APT, 67Zn NMR and possibly other techniques at EMSL to better understand the structure of several types of these materials. In particular, we will test the hypothesis that Zn is bound to three hydroxides and either a fourth hydroxide or a histidine imidazole nitrogen, in nanometer-scale inclusions. And we will investigate whether other metals used in HEBs are also bound in nanoclusters.