绿松石及其常见仿制品的矿物学及谱学特征研究

许多; 周征宇

绿松石及其常见仿制品的矿物学及谱学特征研究

许多,
周征宇^,

同济大学海洋与地球科学学院，上海 200092

基金项目:

珠宝玉石标准样品库科技基础条件平台

上海市科学技术委员会科研攻关项目 1350296T001

详细信息

作者简介:
许多(2002-)，男，博士研究生，宝石及材料工艺学专业。E-mail: xuduo200249@126.com

通讯作者:
周征宇(1978-)，男，副教授，宝石及材料工艺学专业。E-mail: 06058@tongji.edu.cn

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出版历程
- 收稿日期: 2024-07-14
- 刊出日期: 2024-10-30

Mineralogical and Spectral Characteristics of Turquoise and Its Common Imitations

XU Duo,
ZHOU Zhengyu^,

School of Ocean and Earth Science, Tongji University, Shanghai 200092, China

摘要

摘要:
绿松石在全世界有着悠久的历史，对于中国文化的起源与发展有着巨大影响。而到了现代，绿松石因其颜色、质地、历史寓意以及宗教韵味而在全世界风靡，绿松石的造假手段也在不断更新，绿松石市场的健康发展受到冲击。本研究选取来自矿区、厂家与可信渠道购得的绿松石及其相似品，通过这些样品研究天然绿松石样品与绿松石仿制品的矿物谱学特征，以期系统性地分析天然绿松石与绿松石仿制品的谱学特征差异，并为鉴定提供科学依据。本文主要通过常规宝石学测试、红外光谱、拉曼光谱、紫外-可见光谱与能谱分析等现代测试技术对天然绿松石及其仿制品样品进行系统的矿物谱学研究, 得出以下结论。
(1) 天然绿松石样品的密度2.45~2.75 g/cm³，折射率1.61~1.63，w(Al₂O₃)为33.84%~34.03%，w(P₂O₅)为29.97%~33.69%，w(Fe₂O₃)为2.60%~3.25%，w(CuO)为8.19%~9.13%。
(2) 结构水、结晶水与磷酸根基团的振动频率决定了天然绿松石的红外吸收光谱与拉曼光谱。其中, 由结构水的伸缩振动致红外吸收峰出现在3 508 cm^-1和3 463 cm^-1处，拉曼光谱谱峰则出现在3 496、3 471、3 448 cm^-1处；弯曲振动致红外吸收峰出现在841 cm^-1和784 cm^-1处，拉曼光谱谱峰出现在812 cm^-1处。结晶水的伸缩振动致红外吸收峰出现在3 287 cm^-1和3 086 cm^-1处，拉曼光谱谱峰出现在3 265 cm^-1和3 069 cm^-1处；弯曲振动致红外吸收峰出现在1 652 cm^-1处，拉曼光谱出现在1 618 cm^-1处。磷酸根基团的伸缩振动致红外吸收峰出现在1 112 cm^-1和1 060 cm^-1处，拉曼光谱出现在1 159、1 102、1 039、937 cm^-1处；弯曲振动致红外吸收峰出现在648、569、483 cm^-1处，拉曼光谱出现在643、589、547、470、414 cm^-1处。天然绿松石的紫外-可见光谱发现有4个吸收峰，分别是位于267 nm处由O^2--Fe³⁺的电荷转移所引起的吸收峰，位于430 nm处由Fe的水合离子中Fe³⁺的d—d电子跃迁所引起的吸收峰，位于670nm与799 nm由Cu的水合离子中Cu²⁺的d—d电子跃迁所引起的两个吸收峰。
(3) 绿松石仿制品品种繁多，市场常见的品种主要包括三水铝石、重晶石、菱镁矿、方解石及多种矿物混合物5大类，其与天然绿松石鉴别较为有效且快速的方法是红外吸收光谱。天然绿松石及其仿制品的鉴别可以通过3 600~3 000 cm^-1和1 200~900 cm^-1范围内的红外吸收峰与绿松石的红外光谱进行比较^[1-2]，且紫外-可见光谱中是否有Fe的水合离子中Fe³⁺的d—d电子跃迁所引起的430 nm处的吸收峰^[3-4]和化学成分中是否含有Cu和Fe这两种绿松石的致色元素作为辅助证据。
- 绿松石 /
- 仿制品 /
- 红外光谱 /
- 拉曼光谱
Abstract:
This article mainly used modern testing techniques such as conventional gemmological tests, infrared spectrometer, Raman spectrometer, ultraviolet visible spectrometer, and energy spectrum analysis to systematically study the mineralogical and spectra characteristics of the turquoise and its imitations purchased from mining areas, manufacturers, and trusted channels. We have come to the following conclusion. The density of natural turquoise is between 2.45-2.75 g/cm³, and the refractive index is between 1.61-1.63. The vibration frequencies of structural water, crystalline water, and phosphate groups determine the infrared absorption spectra and Raman spectra of natural turquoise. The infrared spectrum tests show the IR absorption peaks around 3 508, 3 463, 3 287, 3 086, 1 652, 1 112, 1 060, 841, 784, 648, 569 cm^-1 and 483 cm^-1; Raman spectrum tests show the peaks around 3 496, 3 471, 3 448, 3 265, 3 069, 1 618, 1 159, 1 102, 1 039, 937, 812, 643, 589, 547, 470 cm^-1 and 414 cm^-1; The absorption peaks appear near 267, 430, 670 nm and 799 nm in the UV visible spectrum.
There are many varieties of turquoise's imitation products, commonly seen in the market mainly including trihydrate alumina, barite, magnesite, calcite and mineral mixtures. The most effective and rapid method for distinguishing them from natural turquoise is infrared absorption spectrum of turquoise in the range of 3 600-3 000 cm^-1 and 1 200-900 cm^-1. The presence of an absorption peak at 430 nm in the UV visible spectrum and the presence of Cu and Fe of colouring elements in turquoise can be used as auxiliary evidence.
- turquoise /
- imitation /
- infrared spectroscopy /
- Raman spectroscopy

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图 1 山东昌乐类达碧兹蓝宝石原石切片，修改自参考文献[7]

Figure 1. Trapiche-like sapphire slices from Changle, Shandong Province, modified from reference[7]

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图 1 天然绿松石的红外吸收光谱

Figure 1. Infrared absorption spectrum of natural turquoise

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图 2 五种绿松石仿制品的红外吸收光谱

Figure 2. Infrared absorption spectra of five turquoise imitations

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图 3 天然绿松石的紫外-可见光谱

Figure 3. UV-Visible spectrum of natural turquoise

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参考文献(10)

[1]	Foord E E, Taggart J E. A reexamination of the turquoise group: The mineral aheylite, planerite (redefined), turquoise and coeruleolactite[J]. Mineralogical Magazine. 1998, 62(1): 93-111. doi: 10.1180/002646198547495
[2]	郝月, 先怡衡, 陈英, 等. 新疆天湖东遗址出产绿松石的矿物学特征及原产地溯源研究[J]. 宝石和宝石学杂志(中英文), 2023, 25(6): 84-94. Hao Y, Xian Y H, Chen Y, et al. Mineralogical characteristic and geographic origin tracing of turquoise from Tianhudong site, Xinjiang[J]. Journal of Gems & Gemmology, 2023, 25(6): 84-94. (in Chinese)
[3]	熊燕, 陈全莉. 湖北秦古绿松石的可见吸收光谱特征[J]. 宝石和宝石学杂志(中英文), 2008, 10(2): 34-37. Xiong Y, Chen Q L. Visible absorption spectrum characteristics of Qingu turquoise from Hubei Province[J]. Journal of Gems & Gemmology, 2008, 10(2): 34-37. (in Chinese)
[4]	李克. 安徽马鞍山绿松石电化学处理前后孔隙特征研究[D]. 北京: 中国地质大学, 2017. Li K. A study on pore characteristics difference between natural and electrochemical treated turquoises from Maanshan, Anhui Province[D]. Beijing: China University of Geosciences, 2017. (in Chinese)
[5]	朱莹, 黎晏彰, 鲁安怀, 等. 方解石-白云石-菱镁矿的中远红外光谱学特征研究[J]. 地学前缘, 2022, 29(1): 459-469. Zhu Y, Li Y Z, Lu A H, et al. Middle and far infrared spectroscopic analysis of calcite, dolomite and magnesite[J]. Earth Science Frontiers, 2022, 29(1): 459-469. (in Chinese)
[6]	杨池玉, 汤维茜, 张维肖, 等. 重晶石、三水铝石及方解石混合物仿绿松石与天然绿松石的光谱特征及化学成分对比[J]. 宝石和宝石学杂志(中英文), 2024, 26 (1): 57-63. Yang C Y, Tang W X, Zhang W X, et al. Comparison of spectral characteristic and chemical compostion of barite, diaspore and calcite mixture imitated turquoise and natural turquoise[J]. Journal of Gems & Gemmology, 2024, 26(1): 57-63. (in Chinese)
[7]	戴慧, 亓利剑, 蒋小平, 等. 含环氧树脂的胶黏剂充填处理及染色处理绿松石的谱学特征[C]//2013中国珠宝首饰学术交流会. 北京: 中国宝石, 2013: 182-186. Dai H, Qi L J, Jiang X P, et al. The spectroscopic characteristics of turquoises filled by epoxy resin adhesives and dyeing treated turquoises[C]//2013 China Gems & Jewelry Academic Conference. Beijing: China Gems, 2013: 182-186. (in Chinese)
[8]	刘喜锋, 林晨露, 李丹丹, 等. 新疆哈密绿松石的矿物学和光谱学特征研究[J]. 光谱学与光谱分析, 2018, 38(4): 1 231-1 239. Liu X F, Lin C L, Li D D, et al. Study on mineralogy and spectroscopy of turquoises from Hami, Xinjiang[J]. Spectroscopy and Spectral Analysis, 2018, 38(4): 1 231-1 239. (in Chinese)
[9]	陈全莉, 张琰. 具磷灰石假象绿松石的宝石矿物学特征[J]. 宝石和宝石学杂志(中英文), 2005, 7(4): 13-16, 32. Chen Q L, Zhang Y. Features of gem-mineralogy of apatite-pseudomorphic turquoise[J]. Journal of Gems & Gemmology, 2005, 7(4): 13-16, 32. (in Chinese)
[10]	库雅伦, 杨明星. 湖北十堰蓝色"水波纹"绿松石的谱学特征[J]. 光谱学与光谱分析, 2021, 41(2): 636-642. Ku Y L, Yang M X. Study on spectral characteristics of turquoise with blue "water ripple" from Shiyan, Hubei Province[J]. Spectroscopy and Spectral Analysis, 2021, 41(2): 636-642. (in Chinese)