Modification of Pearl Surface Microstructure by Rare Earth Cerium Induced Growing

The beautiful luster of freshwater pearls is closely related to its multiplayer microstructure. We present the improvement of their luster by refinement their superficial microstructure of pearls by rare earth cerium (REE) inducing grown. The pearls were cultured in freshwater containing 0 (control group), 0.5, and 1 mg.L-1 REE Ce additive, respectively. As the concentration of Ce in the aqueous increasing, we find that their superficial microstructure take large change. The shape of the blocks that builds up the microstructure changes from anomalous to round discs, and finally to perfect regular square sheets. Correspondingly, the glossiness of the pearls changed with the microstructure, in which the pearls with the regular hexagonal blocks having the highest glossiness.