[Raman spectra of nacre from shells of main pearl-culturing mollusk in China].

The Raman spectra of nacre and cultured pearl from main pearl-culturing mollusks in China have been studied systematically in this paper. It shows that: 1) the Raman bands caused by organic matrix have not been observed in nacre from shell of pinctada maxima; 2) in nacre from shell of pinctada martensii and hyriopsis cumingii, besides the bands caused by aragonite mineral, two bands resulted from all-trans carotenoid are obviously observed, and the number of C=C double bonds in molecular of this carotenoid is predicted to be 10 based on the position of its Raman bands; 3) a number of complicated bands are observed in nacre from shell of peteria penguin, and we predicted that this bands perhaps are caused by metalloporphyrin compounds; 4) the relative concentrations of carotenoid and metalloporphyrin in nacre are closely associated with the color of nacre. The Raman spectra research on organic matrix in nacre and cultured pearl provides insight into the applications of them in cosmetics and food, as well as in application of pearl bleaching.