青海三岔河灰紫色软玉颜色定量表达与紫色成因研究

发布时间：2018-10-10 16:36

【摘要】：颜色是衡量宝玉石品质、价格的重要因素,对宝玉石颜色的量化研究一直是宝石科学关注的热点。在透射光条件下观察宝玉石颜色特征是珠宝行业中十分重要的手段。本研究致力于依赖光谱和光谱分析技术,建立一套依照透射法实现软玉颜色定量表达、颜色复原和确定致色机制的方法。以来自中国青海格尔木地区、具有渐变颜色特点的灰紫色软玉为例,采用紫外-可见吸收光谱(UV-Vis)定量测量、结合国际照明委员会1976 CIE L*a*b*色度学模型转化及计算机软件处理(Adobe Photoshop),实现对特定厚度(1.0 mm)灰紫色软玉样品颜色的定量表达和颜色复原。样品浅色和深色区域复原的颜色与样品透射光下肉眼观察颜色较为接近,存在的色差可能与玉石样品的半透明多晶质结构有关。而对于紫色的致色机理,通过激光剥蚀电感耦合等离子质谱仪(LA-ICP-MS),我们发现微量元素Mn含量随颜色加深呈现递增规律。在较深颜色区域,光致发光光谱(PL)中检测到的以585 nm为中心的发射峰、UV-Vis光谱中以530 nm为中心的吸收峰,以及电子顺磁共振光谱(EPR)的六重超精细分裂峰都在指示Mn~(2+)是导致灰紫色软玉中紫色调的主要原因。本工作对于研究透射光条件下宝玉石样品颜色定量观测和表达提供了确切的实验方法依据,并为采用光谱学确定致色元素以及致色机理提供了有价值的实验信息。
[Abstract]:Color is an important factor to measure the quality and price of Baoyu stone. It is very important to observe the color characteristics of Baoyu stone in the jewelry industry under the condition of transmitted light. Based on spectral and spectral analysis techniques, a set of methods for quantitative color expression, color restoration and chromogenic mechanism of nephrite were established. Taking grayish purple nephrite from Golmud area of Qinghai Province of China as an example, UV-Vis absorption spectroscopy (UV-Vis) was used to measure the grayish purple nephrite. Combined with the transformation of the 1976 CIE Lnab * chromaticity model of the International Lighting Commission and the processing of (Adobe Photoshop), by computer software, the quantitative expression and color restoration of the color of the grayish purple nephrite samples with specific thickness (1.0 mm) are realized. The light color and dark color of the samples are similar to those observed by the naked eye under the transmitted light, and the color difference may be related to the translucent polycrystalline structure of the samples. For the color mechanism of purple, we find that the content of trace element Mn increases with the deepening of color by laser denudation inductively coupled plasma mass spectrometer (LA-ICP-MS). In the darker color region, the emission peak centered on 585 nm was detected in photoluminescence (PL) and the absorption peak at 530 nm in UV-Vis spectrum. The six hyperfine splitting peaks of electron paramagnetic resonance spectroscopy (EPR) indicate that Mn~ (2) is the main cause of purple hue in gray-purple nephrite. This work provides an accurate experimental basis for the quantitative observation and expression of the color of Baoyu samples under the condition of transmitted light, and provides valuable experimental information for the determination of chromogenic elements and chromogenic mechanism by means of spectroscopy.
【作者单位】：中国地质大学(武汉)珠宝学院;
【基金】：国家自然科学基金项目(41230103) 湖北省自然科学基金项目(2014CFB347) 中央高校新青年教师科研启动基金项目(20140139043) 国家质量监督检验检疫总局《和田玉颜色感官评价方法及主要产地鉴别特征研究》项目(201210228)资助
【分类号】：TS933;O432.3

【相似文献】