Flowerlike agglomerates of calcium carbonate crystals formed on an eggshell membrane

Calcium carbonate was crystallized on an eggshell membrane using a specially designed crystallizer. The crystallizer used was a jacketed cylindrical glass vessel with two compartments divided by an eggshell membrane. The calcium chloride and sodium carbonate solutions were separately placed in the two compartments. Several kinds of peculiar agglomerates of calcium carbonate crystals formed on both surfaces of the eggshell membrane. Flowerlike agglomerates formed on the inner surface of the eggshell membrane that is the egg white side, but those were not formed on the outer surface of the membrane. The flowerlike agglomerate was composed of a hemispherical core and petal-like crystals growing around the core. We named it the CC ( calcium carbonate)-flower. The different types of agglomerates formed on the outer surface of the membrane. For instance, when the outer surface of the membrane faced the calcium chloride solution, spherical agglomerates composed of long, needlelike crystals were obtained. We inferred that the surface structure of the eggshell membrane played an important role for the formation of such peculiar agglomerates.