Biomineralization is the biogenic formation of a composite material consisting of organic and anorganic material. In the case of nacre (mother of pearl) the organic material includes proteins, polysaccharides and probably lipids and the anorganic material is aragonite a calciumcarbonate polymorph. This polymer/ceramic composite material is of an extraordinal beauty, is well structured and has very interesting mechanical properties. Aragonite tablets with a diameter in the micrometer range and a height of approximately 0.5 micrometer form confluent layers. The aragonite tablets are embedded in an organic matrix consisting of interlamellar sheets, connecting elements between the sheets and intracrystalline proteins. The interlamellar sheets are multilayers with a core of insoluble material (predominantly chitin) embedded in tightly connected water insoluble and water soluble protein layers. This highly structured material forms in a self organization process. We investigate this material by different techniques including SEM (scanning electron microscopy), TEM (transmission electron microscopy), AFM (atomic force microscopy) biochemical methods, molecular dynamics simulations, protein sequencing and purifying methods.