Photoluminescence Spectra of Tahitian Cultured Black Pearls

The photoluminescence spectra of various Tahitian cultured black pearls have been tested.The results show that there are mainly five bands:5 97,61 9,65 3,676nm and a broad band which varies in the range 70 0~ 890 nm.The three bands,61 9,65 3and 676nm,are thought to be due to a kind of black pigment,and can be used in identifying pearls from Pincta-da magaritifera from naturally-coloured black pearls.