Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy
BACKGROUND Akoya pearl is a biomineralized organic gemstone. The mineral composition and microtextural analysis, and the identification method of color formation of this type of pearl are still lacking. OBJECTIVES To identify natural gray pearls from treated-color gray pearls. METHODS The spectrosco...
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| Format: | Article |
| Language: | English |
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Science Press, PR China
2019-09-01
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| Series: | Yankuang ceshi |
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| Online Access: | http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201809280109 |
| _version_ | 1797953783144120320 |
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| author | SHAO Hui-ping YAN Xue-jun YAN Jun WANG Jin YU Si-yi PENG Qiu-jin HU Xian-chao |
| author_facet | SHAO Hui-ping YAN Xue-jun YAN Jun WANG Jin YU Si-yi PENG Qiu-jin HU Xian-chao |
| author_sort | SHAO Hui-ping |
| collection | DOAJ |
| description | BACKGROUND Akoya pearl is a biomineralized organic gemstone. The mineral composition and microtextural analysis, and the identification method of color formation of this type of pearl are still lacking. OBJECTIVES To identify natural gray pearls from treated-color gray pearls. METHODS The spectroscopic and textural characteristics of two kinds of seawater cultured gray pearls with white or gray nucleus were comparatively investigated by optical microscope, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, and energy dispersive X-ray fluorescence spectrometry. RESULTS The gray pearls with white or gray nucleus had diameters from 5mm to 9mm, the thickness of 300-500μm. The nacreous layer and its corresponding nucleus of the two kinds of gray pearls were composed mainly of biological aragonite, and their corresponding nacreous layers were rich in Sr and poor in Mn. The pearl with the gray nucleus was rich in Mn. The valence state of Mn was increased due to irradiation, resulting in gray of the pearl core and the whole pearl. In general, the pearls with a white nucleus had an obvious reflection band from 300nm to 400nm in the ultraviolet-visible absorption spectra. On the contrary, those pearls with a light or heavy gray nucleus had a reflection band from 400nm to 500nm. CONCLUSIONS The two types of gray pearls are all marine cultured pearls. The difference of ultraviolet absorption spectra of the two types of pearls can be used as a basis for judging whether the gray pearls are irradiatedly colored. |
| first_indexed | 2024-04-10T23:07:32Z |
| format | Article |
| id | doaj.art-18d1015108fd4a878a5d6745f5c1bc6c |
| institution | Directory Open Access Journal |
| issn | 0254-5357 |
| language | English |
| last_indexed | 2024-04-10T23:07:32Z |
| publishDate | 2019-09-01 |
| publisher | Science Press, PR China |
| record_format | Article |
| series | Yankuang ceshi |
| spelling | doaj.art-18d1015108fd4a878a5d6745f5c1bc6c2023-01-13T10:00:57ZengScience Press, PR ChinaYankuang ceshi0254-53572019-09-0138548949610.15898/j.cnki.11-2131/td.201809280109ykcs-38-5-489Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption SpectroscopySHAO Hui-ping0YAN Xue-jun1YAN Jun2WANG Jin3YU Si-yi4PENG Qiu-jin5HU Xian-chao6Zhejiang Fangyuan Test Group Co., LTD, Hangzhou 310013, ChinaZhejiang Fangyuan Test Group Co., LTD, Hangzhou 310013, ChinaZhejiang Fangyuan Test Group Co., LTD, Hangzhou 310013, ChinaWenzhou Institute of Science and Technology, Zhejiang University of Technology, Wenzhou 325024, ChinaZhejiang Fangyuan Test Group Co., LTD, Hangzhou 310013, ChinaZhejiang Fangyuan Test Group Co., LTD, Hangzhou 310013, ChinaResearch Center of Analysis and Measurement, Zhejiang University of Technology, Hangzhou 310014, ChinaBACKGROUND Akoya pearl is a biomineralized organic gemstone. The mineral composition and microtextural analysis, and the identification method of color formation of this type of pearl are still lacking. OBJECTIVES To identify natural gray pearls from treated-color gray pearls. METHODS The spectroscopic and textural characteristics of two kinds of seawater cultured gray pearls with white or gray nucleus were comparatively investigated by optical microscope, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, and energy dispersive X-ray fluorescence spectrometry. RESULTS The gray pearls with white or gray nucleus had diameters from 5mm to 9mm, the thickness of 300-500μm. The nacreous layer and its corresponding nucleus of the two kinds of gray pearls were composed mainly of biological aragonite, and their corresponding nacreous layers were rich in Sr and poor in Mn. The pearl with the gray nucleus was rich in Mn. The valence state of Mn was increased due to irradiation, resulting in gray of the pearl core and the whole pearl. In general, the pearls with a white nucleus had an obvious reflection band from 300nm to 400nm in the ultraviolet-visible absorption spectra. On the contrary, those pearls with a light or heavy gray nucleus had a reflection band from 400nm to 500nm. CONCLUSIONS The two types of gray pearls are all marine cultured pearls. The difference of ultraviolet absorption spectra of the two types of pearls can be used as a basis for judging whether the gray pearls are irradiatedly colored.http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201809280109gray pearlultraviolet-visible absorption spectroscopystructurenacreous layernucleusirradiation treatment |
| spellingShingle | SHAO Hui-ping YAN Xue-jun YAN Jun WANG Jin YU Si-yi PENG Qiu-jin HU Xian-chao Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy Yankuang ceshi gray pearl ultraviolet-visible absorption spectroscopy structure nacreous layer nucleus irradiation treatment |
| title | Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy |
| title_full | Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy |
| title_fullStr | Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy |
| title_full_unstemmed | Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy |
| title_short | Identification of Two Kinds of Seawater Cultured Gray Pearls by Fourier Transform Infrared Spectroscopy and Ultraviolet-visible Absorption Spectroscopy |
| title_sort | identification of two kinds of seawater cultured gray pearls by fourier transform infrared spectroscopy and ultraviolet visible absorption spectroscopy |
| topic | gray pearl ultraviolet-visible absorption spectroscopy structure nacreous layer nucleus irradiation treatment |
| url | http://www.ykcs.ac.cn/en/article/doi/10.15898/j.cnki.11-2131/td.201809280109 |
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