Structure of Organic Matrix

Tabic 2. Amino acid composition of various carbonates, in residucs/lOOO109, 110, 22°  

Amino acid Hydroides (Serpulid) (Worm tubes) Porites (Sclerac- tinian) (coral) k unicea (Alcyo- narian) (coral) Oolites (Bahamas) Aragonite Needle mud (Bahamas) 

Heating experiments on Nautilus shell material (see page 10) indicates a retardation in the rates of thermal decomposition of mineral and organic phase. This has been attributed to the development of a topochemical boundary at the contact protein-mineral. X-ray diffraction analysis gives no evidence for structural alteration of the original aragonite during the thermal treatment up to 200 °C. 

The organic matrix follows the same pattern. By means of electron diffraction analysis it can be shown that the protein matrix is and remains crystalline and that the structural order of the diffraction pattern is that of a microcrystalline film of gold (Fig. 23)224). It is remarkable that the matrix proteins in other species also produce a single crystal spot pattern. This implies that isolated pieces of organic matrix which are in the order of a few microns thick represent single crystals. Whatever the term single crystal may mean to the various researchers43, in the context 

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