珍珠的金黄色染色工艺及染色珍珠的鉴定

Technology and Identification of Golden Dyed Pearls

使用有机染料直接冻黄(C28H24O8N4S2)对淡水珍珠进行染金黄色实验。通过正交实验分析了影响染色效果的4种因素,获得了相对理想的染色条件。在对珍珠染色的膨化处理和固色处理中发现,使用蒸馏水降低膨化剂中苯和氨水的浓度,可以降低化学试剂对珍珠层的破坏,对珍珠层质地较疏松的珍珠尤为有效。对比常用的两种固色方法发现,硫酸铜溶液对染色珍珠的固色效果较好。染金黄色珍珠的主要鉴定特征为:染色珍珠表面的瑕疵、裂纹及孔眼处都有颜色浓集的现象;在紫外灯下染色珍珠发强黄绿色荧光,其拉曼光谱显示很强的荧光背景。

The golden dyed experiments of freshwater cultured pearl samples are done by chrysophenine G dyeing. The relative perfect conditions for dyeing are acquired by using orthogonal experiments for analysing four influence factors of dyeing. The results of expanding treatment and colour fixation treatment show that the concentration of expanding solvent including benzenne and ammonia decreased by distill water can reduce the damage to the nacreous layers of pearls, especially for loose layers of pearl samples. The bluestone liquor is more fit for colour fixation treatment. The identification characteristics of golden dyed pearls are that the dyestuff is concentrated into the blemish, crack and drilled holes on the surface of the samples. The yellowish green fluorescence from the samples could be observed under ultraviolet light, and the Raman spectra show the strong fluorescence background.