Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite
The color-influencing factors and spectroscopy of 22 green elbaite samples were investigated using X-Rite SP62 spectrophotometry, ultraviolet–visible (UV–Vis) spectroscopy, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and infrared spectroscopy. The chromogenic components...
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MDPI AG
2023-10-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/13/10/1461 |
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| author | Lianyi Cui Ying Guo Jun Tang Yushu Yang |
| author_facet | Lianyi Cui Ying Guo Jun Tang Yushu Yang |
| author_sort | Lianyi Cui |
| collection | DOAJ |
| description | The color-influencing factors and spectroscopy of 22 green elbaite samples were investigated using X-Rite SP62 spectrophotometry, ultraviolet–visible (UV–Vis) spectroscopy, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and infrared spectroscopy. The chromogenic components iron and manganese were found in the green elbaites; however, the bivariate correlation analysis indicated that the Mn content had no impact on the color, whereas the Fe content significantly affected both the lightness and the hue of green elbaites. The primary factors influencing the color of tourmaline were the absorption band at 720 nm caused by the Fe<sup>2+</sup> d-d transitions and the 300 to 400 nm wide absorption edge extending to the visible range due to the O<sup>2−</sup>-Fe<sup>3+</sup> charge transfer. Infrared spectroscopy indicated that the color of tourmalines was also influenced by their structure. As the degree of <i>Y</i> and <i>Z</i> octahedral distortion in the tourmaline lattice increased, the lightness of the tourmaline decreased and its color deepened. The hydroxyl region of the infrared spectra of green elbaite showed three distinct peak positions representing two types of hydroxyl vibrations: O1H at the <i>W</i> position and O3H at the <i>V</i> position. The O1H vibrations are attributed to <i><sup>Y</sup></i>Li<i><sup>Y</sup></i>Al<i><sup>Y</sup></i>Al and <i><sup>X</sup></i>Na or <i>X</i> position vacancy, while the O3H vibrations are assigned to <i><sup>Z</sup></i>Al<i><sup>Z</sup></i>Al<i><sup>Y</sup></i>Al and <i><sup>Z</sup></i>Al<i><sup>Z</sup></i>Al<i><sup>Y</sup></i>Li. The presence of three peaks in the hydroxyl vibrational region of the IR spectra indicated that these samples were iron-bearing elbaites. |
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| language | English |
| last_indexed | 2024-03-10T21:19:40Z |
| publishDate | 2023-10-01 |
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| spelling | doaj.art-616ca588e7b7485e9b25cdc67b489ca82023-11-19T16:09:33ZengMDPI AGCrystals2073-43522023-10-011310146110.3390/cryst13101461Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing ElbaiteLianyi Cui0Ying Guo1Jun Tang2Yushu Yang3School of Gemmology, China University of Geoscience (Beijing), Beijing 100083, ChinaSchool of Gemmology, China University of Geoscience (Beijing), Beijing 100083, ChinaSchool of Gemmology, China University of Geoscience (Beijing), Beijing 100083, ChinaSchool of Gemmology, China University of Geoscience (Beijing), Beijing 100083, ChinaThe color-influencing factors and spectroscopy of 22 green elbaite samples were investigated using X-Rite SP62 spectrophotometry, ultraviolet–visible (UV–Vis) spectroscopy, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and infrared spectroscopy. The chromogenic components iron and manganese were found in the green elbaites; however, the bivariate correlation analysis indicated that the Mn content had no impact on the color, whereas the Fe content significantly affected both the lightness and the hue of green elbaites. The primary factors influencing the color of tourmaline were the absorption band at 720 nm caused by the Fe<sup>2+</sup> d-d transitions and the 300 to 400 nm wide absorption edge extending to the visible range due to the O<sup>2−</sup>-Fe<sup>3+</sup> charge transfer. Infrared spectroscopy indicated that the color of tourmalines was also influenced by their structure. As the degree of <i>Y</i> and <i>Z</i> octahedral distortion in the tourmaline lattice increased, the lightness of the tourmaline decreased and its color deepened. The hydroxyl region of the infrared spectra of green elbaite showed three distinct peak positions representing two types of hydroxyl vibrations: O1H at the <i>W</i> position and O3H at the <i>V</i> position. The O1H vibrations are attributed to <i><sup>Y</sup></i>Li<i><sup>Y</sup></i>Al<i><sup>Y</sup></i>Al and <i><sup>X</sup></i>Na or <i>X</i> position vacancy, while the O3H vibrations are assigned to <i><sup>Z</sup></i>Al<i><sup>Z</sup></i>Al<i><sup>Y</sup></i>Al and <i><sup>Z</sup></i>Al<i><sup>Z</sup></i>Al<i><sup>Y</sup></i>Li. The presence of three peaks in the hydroxyl vibrational region of the IR spectra indicated that these samples were iron-bearing elbaites.https://www.mdpi.com/2073-4352/13/10/1461color-influencing factorselbaiteinfrared spectroscopytourmalinehydroxyl vibration |
| spellingShingle | Lianyi Cui Ying Guo Jun Tang Yushu Yang Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite Crystals color-influencing factors elbaite infrared spectroscopy tourmaline hydroxyl vibration |
| title | Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite |
| title_full | Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite |
| title_fullStr | Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite |
| title_full_unstemmed | Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite |
| title_short | Spectroscopy Characteristics and Color-Influencing Factors of Green Iron-Bearing Elbaite |
| title_sort | spectroscopy characteristics and color influencing factors of green iron bearing elbaite |
| topic | color-influencing factors elbaite infrared spectroscopy tourmaline hydroxyl vibration |
| url | https://www.mdpi.com/2073-4352/13/10/1461 |
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