Study of the Influence of Rear Earth Elements on Microstructure of Pearl Surface Observed by SEM

Abstract

We investigated the influence of rare earth element (REE) Ce on the surface microstructure of bivalves pearl in the scaled of micro and nanometer range by means of scanning electronic microscopy (SEM). And we discussed the relevant of surface microstructure and lustrous of pearls to the concentration of REE in culture water by analyzing the influence of additive REE on the surface microstructure. We found that pseudo-hexagonal relatively grow slowly when REE Ce was absent in the culturing water, and the pearls surface were mainly build up by spindly aragonite blocks. On the contrary, the pearls grow quickly when REE was added in the culturing water, and the pearls surface were chiefly composed of regular hexagonal aragonite blocks that is the most idea blocks in crystallography. The results show that an appropriate quantity of Ce will promote the development and growth of pearls, and enhanced the lustrous of pearls significantly. However, as the REE concentration is large, the blocks composed of pearls became to around, and oval dics, thus leading the roughness increasing of pearls surface and the lustrous decrease.