采用紫外-可见(ultraviolet-visible, UV-Vis)反射光谱并结合405 nm为激发光源的光致发光(photoluminescence, PL)光谱对海水养殖的黑色系珍珠进行较系统的光谱采集、 比对, 以期探究天然色黑色珍珠在上述光谱中的异同特性。 结果表明: (1)基于UV-Vis反射光谱中250~800 nm区间的谱图特征, 首次将黑色系珍珠的UV-Vis反射特性归类为四大类, 即①在约400, 500和700 nm处均存在吸收峰; ②在约400和500 nm两处存在吸收峰; ③在约400和700 nm两处存在吸收峰; ④在约500和700 nm两处存在吸收峰; (2)在405 nm激发光源下, 黑色珍珠的PL光谱在约620, 653和677 nm处皆出现特征吸收, 上述各吸收峰位在其他类别的淡海水珍珠的PL光谱中未曾见有具体报道。 且有趣的是, 首次发现黑色珍珠的PL光谱中约677 nm处的特征吸收峰表现出较强的光敏特征, 即随着激发光源辐照时间的延长, 该处吸收峰的强度渐弱甚至消失。 研究结果可为黑色系珍珠其颜色形成属性的鉴定、 判断提供理论与技术支撑。

The spectral characteristics of seawater cultured black pearl were systematically investigated by ultraviolet-visible (UV-Vis) reflection spectrometer combining with photoluminescence (PL) spectrometer. The results show that: (1) based on the intensity and presence of the absorption peaks located at around 400, 500 and 700 nm in the UV-Vis reflection spectra, the black pearls were firstly classified into four categories. Namely, firstly, most of the pearls have absorption at around 400, 500 and 700 nm. Secondly, a small number of pearls have absorption peaks at around about 400 and 500 nm. Thirdly, partly of pearls absorption appeared peaks at about 400 and 700 nm. Finally, the rest of the pearls in this work appeared absorption peak around 500 and 700 nm. (2) Under the condition of 405 nm excitation light source and the room temperature, the unique characteristic absorption was located at around 620, 653 and 677 nm in PL spectra of black pearls, which did not appear in the other kinds of pearls. Interestingly, of which about 677 nm absorption peak had a sensitive to ultraviolet light, namely with the extension of irradiation time, the intensity of the absorption peak becomes weak or even disappears. In a word, the technology UV-Vis reflection combined with PL spectrum will take an important role in the identification of black pearls.