Study on Colour and Identification Characteristics of Natural and Dyed Fire Opal in the Market

ZHAO Bo; HU Zhikun; HAN Dong; PAN Yiwen; ZHU Meidong; CHEN Cheng

doi:10.15964/j.cnki.027jgg.2022.01.005

Volume 24 Issue 1

Feb. 2022

Turn off MathJax

Article Contents

Abstract

References

Journal of Gems & Gemmology > 2022 > 24(1): 39-47. > DOI: 10.15964/j.cnki.027jgg.2022.01.005

ZHAO Bo, HU Zhikun, HAN Dong, PAN Yiwen, ZHU Meidong, CHEN Cheng. Study on Colour and Identification Characteristics of Natural and Dyed Fire Opal in the Market[J]. Journal of Gems & Gemmology, 2022, 24(1): 39-47. DOI: 10.15964/j.cnki.027jgg.2022.01.005

Citation:

PDF (6266 KB)

Study on Colour and Identification Characteristics of Natural and Dyed Fire Opal in the Market

1.
National Gemstone Testing Center Shanghai Lab, Shanghai 200122, China
2.
National Gemstone Testing Center Shanghai Lab, Shenzhen 518020, China
3.
School of Energy and Materials, Shanghai Polytechnic University, Shanghai 201209, China

More Information

Received Date: September 07, 2021

Graphical Abstract

Abstract

Abstract

Fire opal as a rare opal variety in the market has been widely loved. The cause and identification of the colour of fire opal has always been a difficult problem in testing. As the market demand for dyed fire opal identification becomes more and more urgent, it has a certain degree of significance in research and application.This article selected the common natural and dyed fire opals in the market as the research objects. Conventional gemmological tests, microscopic observations, Fourier infrared spectrometer, DiamondView^TM, photoluminescence spectroscopy, ultraviolet-visible spectroscopy and Raman spectroscopy tests were done to analyze the gemmological characteristics and identification methods of common fire opals from different areas on the market, which may provide clues to explore the method of distinguishing natural body colour fire opal and dyed fire opal by conventional laboratory technique.Research results showed that most natural fire opals are uneven in colour to some extent, while dyed samples not. There are some significant differences in the fluorescence images of natural and dyed fire opal under DiamondView^TM. Infrared and Raman spectroscopy can assist in distinguishing the fire opal origin. Dyed samples from Africa had the dye absorption peaks within the range from 1 200 to 1 600 cm^-1. There are also some difference of peak shape and absorption peak between dyed and natural fire opal in PL test. There was no obvious difference between the dyeing fire opal and natural fire opal in UV-Vis spectra.The full contrast of appearance features and the comprehensive analysis of spectral and luminescent characteristics can be used to distinguish the colour origin of the fire opal in practice.
- fire opal,
- dyed fire opal,
- cause of colour,
- identification characteristic

FullText(HTML)

References (9)

References

[1]	陈永洁. 欧泊收藏与鉴赏[M]. 上海: 上海交通大学出版社, 2012: 13-64. Chen Y J. Opal collection and appreciation[M]. Shanghai: Shanghai Jiao Tong University Press, 2012: 13-64. (in Chinese)
[2]	Li J, Yin K, Han W, et al. Mineralogical characteristics and cause of color of a red fire opal[J]. Journal of Computational and Theoretical Nanoscience, 2016, 13(3): 2 082-2 086. doi: 10.1166/jctn.2016.5159
[3]	李建军, 刘晓伟, 王岳, 等. 不同结晶程度SiO₂的红外光谱特征及其意义[J]. 红外, 2010, (12): 31-35. https://www.cnki.com.cn/Article/CJFDTOTAL-HWAI201012011.htm Li J J, Liu X W, Wang Y, et al. Infrared spectral features of SiO₂ with different crystallinity and their implications[J]. Infrared, 2010(12): 31-35. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-HWAI201012011.htm
[4]	Wray R A L. Opal and chalcedony speleothems on quartz sandstones in Sydney regions, south-eastern Australia[J]. Australian Journal of Earth Sciences, 1999(46): 623-632.
[5]	祖恩东, 李茂材, 张鹏翔. 二氧化硅类玉石的显微拉曼光谱研究[J]. 昆明理工大学学报(自然科学版), 2000, 25(3): 77-78, 84. doi: 10.3969/j.issn.1007-855X.2000.03.021 Zu E D, Li M C, Zhang P X. Study on jades of SiO₂ by Raman spectroscopy[J]. Journal of Kunming University of Science and Technology, 2000, 25(3): 77-78, 84. (in Chinese) doi: 10.3969/j.issn.1007-855X.2000.03.021
[6]	周佳妮, 尹作为. 埃塞俄比亚欧泊微结构及变彩成因探讨[J]. 宝石和宝石学杂志(中英文), 2018, 20(3): 18-27. https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB201803003.htm Zhou J N, Yin Z W. Microstructure and play-of-colour of Ethiopian opal[J]. Journal of Gems & Gemmology, 2018, 20(3): 18-27. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB201803003.htm
[7]	张勇, 陆太进, 杨天畅, 等. 石英质玉石的颜色分布及其微量元素分析[J]. 岩石矿物学杂志, 2014, 33(S1): 83-88. https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW2014S1015.htm Zhang Y, Lu T J, Yang T C, et al. A study of quartzite jade's color and trace elements[J]. Acta Petrologica Et Mineralogica, 2014, 33(S1): 83-88. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YSKW2014S1015.htm
[8]	Pan X, Guo Y, Liu Z Y, et al. Impact of different standard lighting sources on red jadeite and color quality grading[J]. Earth Sciences Research Journal, 2019, 23(4): 371-378. doi: 10.15446/esrj.v23n4.84113
[9]	Rondeau B, Cenki-Tok B, Fritsch E. Geochemical and petrological characterization of gem opals from Wegel Tena, Wollo, Ethiopia: Opal formation in an Oligocene soil[J]. Geochemistry: Exploration, Environment, Analysis, 2012, 12(2): 93-104.