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借助偏光显微镜和X射线粉晶衍射仪、电子探针、紫外-可见-近红外分光光度计等现代仪器设备,对桂林鸡血玉的显微结构、矿物组成及致色机理进行分析和探讨。桂林鸡血玉的颜色多样,包括红色、“红血黑地”、黄色、紫色和绿色5大系列。玉石主要为他形等粒变晶结构,部分区域可见变斑晶结构,主要矿物为微晶质—隐晶质石英,次要矿物主要为赤铁矿,部分玉石中还有少量的绿泥石、滑石甚至白云石等,w(SiO2_)介于94.92%到99.65%之间。不同形态的赤铁矿及其他矿物杂质是引起玉石颜色多样性的主要原因,[FeO_4]~(4-)空穴色心对可见光的选择性吸收使玉石呈现紫色。鸡血玉的红色与细尘状赤铁矿密切相关,细尘状赤铁矿越密集玉石的颜色越深,细尘状赤铁矿含水时鸡血玉的红色较为鲜艳;不同色调的黑色鸡血玉主要由鳞片状赤铁矿或集合体磁铁矿致色;黄色主要由氧化铁的含水矿物——针铁矿所引起,且随着鳞片状赤铁矿含量的增加,颜色逐渐偏向于橙黄色;不同色调的鳞片状绿泥石是玉石呈绿色的根本原因,滑石和白云石对玉石的颜色没有直接的影响,但它们的存在使玉石的光泽变暗、透明度降低。
The microstructure, mineral composition and mechanism of chicken blood jade in Guilin were analyzed and discussed with the aid of polarization microscope and X-ray powder diffraction, electron probe and UV-VIS-NIR spectrophotometer. Guilin chicken blood jade color varied, including red, “red blood black ”, yellow, purple and green 5 series. The jadeite is mainly of the hematite-like crystal structure. Part of the area is characterized by a porphyry structure. The main minerals are microcrystalline-cryptocrystalline quartz, the minor minerals are mainly hematite, and some jade also contain a small amount of chlorite , Talc or even dolomite, w (SiO2_) is between 94.92% and 99.65%. Different forms of hematite and other mineral impurities are the main causes of jade color diversity. The selective absorption of visible light by [FeO 4] ~ (4-) hole color centers makes jade purple. The red of chicken blood jade is closely related to fine dusty hematite, the darker the color of the jagged jadeite is, the more intense the fine dusty hematite is, Blood jade is mainly composed of scaly hematite or aggregated magnetite; yellow is mainly caused by goethite, an iron ore that is an aqueous mineral of iron oxide, and the color is gradually biased toward the increase of scaly hematite Orange and yellow; different color shades of chlorite is the fundamental cause of jade green, talc and dolomite jade color does not have a direct impact, but their presence diminishes the jade luster, lower transparency.