Spectral Characteristics of Unique Species of Burmese Amber

Special species of Burmese amber are highly valued within the gemological market due to their fancy optical characteristics. However, some ordinary amber species are misidentified as precious species, which has disrupted consumers’ purchasing behavior and the market order. In this study, seven Burme...

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Main Authors: Zhaotong Shi, Chenxing Xin, Yamei Wang
Format: Article
Language:English
Published: MDPI AG 2023-01-01
Series:Minerals
Subjects:
Online Access:https://www.mdpi.com/2075-163X/13/2/151
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author Zhaotong Shi
Chenxing Xin
Yamei Wang
author_facet Zhaotong Shi
Chenxing Xin
Yamei Wang
author_sort Zhaotong Shi
collection DOAJ
description Special species of Burmese amber are highly valued within the gemological market due to their fancy optical characteristics. However, some ordinary amber species are misidentified as precious species, which has disrupted consumers’ purchasing behavior and the market order. In this study, seven Burmese amber species (golden, golden-blue, blood-tea, black-tea, green-tea, brownish-red, and ‘chameleon’ amber) were collected and investigated. By using conventional gemological tests, Fourier transform infrared (FTIR), three-dimensional (3D) fluorescence, and photoluminescence (PL) spectrometers, detailed analyses were performed on unique species. The FTIR spectra identified that there are three groups of peaks that can distinguish Burmese amber from any other origin. Additionally, the ‘Chameleon’ amber exhibited special patterns in the third group, which might be due to its internal aromatic hydrocarbons structures that are different from any other species. The 3D fluorescence spectra displayed that all seven species presented similar fluorescence behavior—the 334 or 347 nm emission wavelength could be optimally excited by 240 or 294 nm excitation wavelength in the ultraviolet region and the 380 ± 10 nm or 400 ± 10 nm excitation wavelength optimally excited the 430 nm emission wavelength in the violet region. In the red region, green-tea amber, black-tea amber, and brownish-red amber presented totally different fluorescence behavior, which could be regarded as a reference feature for differentiation. Obvious pink fluorescence on the surface of the tea amber was efficiently found under PL spectra, and we firstly suggest this test could be used as an effective way to distinguish black-tea amber from green-tea amber and some ordinary species (such as blood-tea amber). Both the PL and 3D fluorescence measurements demonstrated the different luminescence behavior of tea amber in the red region, which might be related to the type and content of red fluorescent substances in the tea amber.
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spelling doaj.art-f2ce59c7fd1f4f0faf4a020f40209b572023-11-16T22:17:36ZengMDPI AGMinerals2075-163X2023-01-0113215110.3390/min13020151Spectral Characteristics of Unique Species of Burmese AmberZhaotong Shi0Chenxing Xin1Yamei Wang2Gemological Institute, China University of Geosciences (Wuhan), Wuhan 430074, ChinaGemological Institute, China University of Geosciences (Wuhan), Wuhan 430074, ChinaGemological Institute, China University of Geosciences (Wuhan), Wuhan 430074, ChinaSpecial species of Burmese amber are highly valued within the gemological market due to their fancy optical characteristics. However, some ordinary amber species are misidentified as precious species, which has disrupted consumers’ purchasing behavior and the market order. In this study, seven Burmese amber species (golden, golden-blue, blood-tea, black-tea, green-tea, brownish-red, and ‘chameleon’ amber) were collected and investigated. By using conventional gemological tests, Fourier transform infrared (FTIR), three-dimensional (3D) fluorescence, and photoluminescence (PL) spectrometers, detailed analyses were performed on unique species. The FTIR spectra identified that there are three groups of peaks that can distinguish Burmese amber from any other origin. Additionally, the ‘Chameleon’ amber exhibited special patterns in the third group, which might be due to its internal aromatic hydrocarbons structures that are different from any other species. The 3D fluorescence spectra displayed that all seven species presented similar fluorescence behavior—the 334 or 347 nm emission wavelength could be optimally excited by 240 or 294 nm excitation wavelength in the ultraviolet region and the 380 ± 10 nm or 400 ± 10 nm excitation wavelength optimally excited the 430 nm emission wavelength in the violet region. In the red region, green-tea amber, black-tea amber, and brownish-red amber presented totally different fluorescence behavior, which could be regarded as a reference feature for differentiation. Obvious pink fluorescence on the surface of the tea amber was efficiently found under PL spectra, and we firstly suggest this test could be used as an effective way to distinguish black-tea amber from green-tea amber and some ordinary species (such as blood-tea amber). Both the PL and 3D fluorescence measurements demonstrated the different luminescence behavior of tea amber in the red region, which might be related to the type and content of red fluorescent substances in the tea amber.https://www.mdpi.com/2075-163X/13/2/151Burmese amberspecial amber speciesoptical effect amberspectrum analysis
spellingShingle Zhaotong Shi
Chenxing Xin
Yamei Wang
Spectral Characteristics of Unique Species of Burmese Amber
Minerals
Burmese amber
special amber species
optical effect amber
spectrum analysis
title Spectral Characteristics of Unique Species of Burmese Amber
title_full Spectral Characteristics of Unique Species of Burmese Amber
title_fullStr Spectral Characteristics of Unique Species of Burmese Amber
title_full_unstemmed Spectral Characteristics of Unique Species of Burmese Amber
title_short Spectral Characteristics of Unique Species of Burmese Amber
title_sort spectral characteristics of unique species of burmese amber
topic Burmese amber
special amber species
optical effect amber
spectrum analysis
url https://www.mdpi.com/2075-163X/13/2/151
work_keys_str_mv AT zhaotongshi spectralcharacteristicsofuniquespeciesofburmeseamber
AT chenxingxin spectralcharacteristicsofuniquespeciesofburmeseamber
AT yameiwang spectralcharacteristicsofuniquespeciesofburmeseamber