秘鲁粉色蛋白石的物相组成及颜色成因

Phase composition and color origin of Peru's pink opals

采用X射线粉晶衍射、红外光谱仪、电子探针、激光剥蚀电感耦合等离子体质谱仪以及紫外可见光分光光度计对不同深浅的秘鲁产粉色蛋白石样品进行了物相组成及颜色成因的测试和分析。结果显示,粉色蛋白石的主要矿物组成为Opal-CT、坡缕石、石英和水,且水的类型较为丰富,包含了结晶水、结构水和沸石水。结合X射线粉晶衍射、红外光谱及电子探针分析认为粉色蛋白石的颜色与坡缕石有关,且通过XRD定量分析坡缕石的含量,认为其与颜色呈正相关。综合紫外-可见光光谱、电子探针和激光剥蚀电感耦合等离子体质谱结果分析,粉色蛋白石的颜色与坡缕石结构中的有机物醌和β类胡萝卜素及Mn^(2+)有关,且Mn^(2+)含量越多,颜色越深,同时提出了Fe^(3+)对颜色的影响,发现Fe^(3+)只出现在了深色样品中。

X-ray powder diffraction,infrared spectroscopy,electron microprobe,laser ablation inductively coupled plasma mass spectrometry and ultraviolet-visible spectrophotometer were used to test and analyze the phase composi-tion and color genesis of different shades of pink opal samples from Peru.The results show that the main mineral composition of pink opal is Opal-CT,palygorskite,quartz and water,and the type of water is rich,including crys-tal water,structural water and zeolite water.Combined with X-ray powder diffraction,electron microprobeand in-frared spectrum analysis,it is considered that the color of pink opal is related to palygorskite,and the content of palygorskite was quantitatively analyzed by XRD,which was positively correlated with color.UV-visible spectro-photometer combined with electron microprobe and laser ablation inductively coupled plasma mass spectrometry showed that the color of pink opal was related to the organic quinones,β-carotene and Mn^(2+),and the more the con-tent of Mn^(2+),the darker the color.At the same time,the effect of Fe^(3+) on color was proposed,and it was found that Fe^(3+) only appeared in dark samples.