Chemical Composition and Spectroscopic Characteristic of Tourmaline with Usambara Effect
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摘要:
Usambara(乌桑巴拉)效应作为一种罕见的光学效应，在电气石上得到了很好的体现，然而对具有该效应的电气石谱学特征研究仍有待完善。本文以一批具有Usambara效应的电气石为研究对象，利用常规宝石学测试仪器、激光剥蚀电感耦合等离子体质谱仪、红外光谱、显微紫外-可见光谱仪以及荧光光谱仪研究其谱学特征。结果表明，这批具有Usambara效应的电气石样品体色均为深绿色，将多片样品重叠，经光源透射，可见透射区域整体颜色变化为红色，符合Usambara效应；激光剥蚀电感耦合等离子体质谱结果表明，该批样品基本属于镁电气石，其微量元素中含有较高的Cr含量；红外光谱显示3 569cm-1处有强的镁电气石特征吸收峰；紫外-可见吸收光谱表明，具有Usambara效应的电气石样品的颜色与Cr的自旋允许电子d-d跃迁以及弱自旋禁阻吸收密切相关；荧光光谱结果显示，可见光波段中有3处激发光源可使样品产生强烈红色荧光, 该荧光由Cr3+多重禁阻跃迁所导致。
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关键词:
- Usambara效应 /
- 电气石 /
- 谱学特征 /
- 颜色成因
Abstract:As a rare optical effect, Usambara effect has been well recorded in tourmaline, but knowledge on the chemical and spectroscopic characteristics of tourmaline with this effect is still to be improved. In this paper, a batch of tourmaline showing Usambara effect is studied using conventional gemmological testing instruments, laser ablation inductively coupled plasma mass spectrometer, infrared spectroscopy, micro-UV-Visible spectrometer and fluorescence spectrometer.The experimental results show that the colour of these tourmaline samples with the Usambara effect is dark green. When multiple samples are overlapped and transmitted by a light source, the overall colour of the visible transmission area changes to red, which is consistent with the Usambara effect. The results of laser ablation inductively coupled plasma mass spectrometry indicate that these samples belong to magnesium tourmaline with high Cr content as trace element. The infrared spectra show a strong absorption peak of magnesium tourmaline at 3 569 cm-1. The ultraviolet-visible absorption spectra show that the colour of the Usambara effect tourmaline samples is closely related to the spin-permitted electron d-d transition and the weak spin-forbidden absorption of Cr. The results of fluorescence spectra show that there are three luminescent centers in the visible range caused by Cr3+ multiple forbidden transitions, which produce strong red fluorescence.
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Keywords:
- Usambara effect /
- tourmaline /
- spectroscopic characteristic /
- colour origin
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图 1 “黑青”样品的近红外吸收光谱Figure 1. Near-infrared absorption spectra of nearly black tremolite-nephrite ("Heiqing")![]()
图 2 “黑碧”样品的近红外吸收光谱Figure 2. Near-infrared absorption spectrum of nearly black actinolite-nephrite ("Heibi")![]()
图 3 “黑青”样品的可见-近红外吸收光谱Figure 3. Visible-near infrared absorption spectra of nearly black tremolite-nephrite ("Heiqing")![]()
图 4 “黑碧”样品的可见-近红外吸收光谱Figure 4. Visible-near infrared absorption spectrum of nearly black actinolite-nephrite ("Heibi") -
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图 1 2 850 K光纤灯照射下电气石样品呈现出的Usambara效应: (a)透射光单独照射样品均呈现绿色调；(b)光源透过重叠在一起的4片样品呈现红色调
Figure 1. Tourmaline samples showing Usambara effect under transmission light of 2 850 K: (a)separate slices show green tone; (b)overlapped slices show red tone)
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图 2 电气石样品的测试点位分布图
注：d为样品厚度
Figure 2. Testing point distribution map of tourmaline samples
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图 3 电气石样品各测试点在X、Y、Z和W位点中的元素投点占位分布三元图
Figure 3. Triple plot of element loading distribution at X, Y, Z, and W sites at each testing point of tourmaline samples
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图 4 电气石样品的红外反射光谱(a)和红外透射光谱(b)
Figure 4. Infrared reflection spectra (a) and infrared transmission spectra (b) of tourmaline samples
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图 5 电气石样品的显微紫外-可见吸收光谱
Figure 5. Ultraviolet-visible absorption spectra of the tourmaline samples
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图 6 电气石样品的透射率及透射窗
Figure 6. The transmission rate and transmission windows of the tourmaline samples
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图 7 电气石样品TS-1的三维荧光光谱、特征激发和发射光谱
Figure 7. 3D fluorescence spectra, characteristic excitation spectra, and emission spectra of the tourmaline sample TS-1
表 1 电气石样品中测试点的化学成分
Table 1 Chemical compositions of the tourmaline samples' testsing points
TS-1-A TS-1-B TS-1-C TS-2-A TS-2-B TS-2-C TS-3-A TS-3-B TS-4-A TS-4-B 主要氧化物/% B2O3 10.68 10.66 10.68 10.68 10.66 10.65 10.66 10.56 10.73 10.62 Na2O 1.53 1.61 1.85 1.62 1.84 1.57 1.58 1.92 1.72 1.78 MgO 11.68 11.50 11.22 11.15 11.17 11.48 11.20 10.67 11.47 11.07 Al2O3 30.44 30.68 30.81 30.97 31.00 30.62 29.72 29.22 32.01 31.35 SiO2 38.02 38.26 38.41 38.29 38.18 37.92 38.29 38.13 38.55 38.20 CaO 2.87 2.74 2.28 2.56 2.13 2.69 2.66 1.97 2.30 2.30 Cr2O3 4.22 3.97 4.16 4.14 4.43 4.48 5.16 6.81 2.73 4.02 微量元素/10-6 Li 17.59 19.38 20.89 18.97 22.00 17.68 17.94 20.42 28.47 19.18 K 385.65 313.77 435.03 303.95 397.82 356.63 366.40 393.92 330.22 474.86 Ti 1 220.96 1 280.66 1 402.69 1 500.30 1 601.93 1 260.74 1 273.57 1 304.43 1 084.88 1 364.05 V 480.72 491.46 510.78 507.53 521.89 521.42 452.46 559.28 271.21 402.11 Mn 20.27 18.41 18.77 19.69 18.35 18.63 19.23 17.55 17.95 19.07 Fe 232.37 247.47 223.28 224.57 234.88 208.52 271.52 258.29 165.09 202.91 Co - - - - - - - - - - Ni* - 5.17 - 5.51 2.40 3.33 - - 1.82 3.50 Cu - - - - - - - - - - 注：*表示该行数据属于半定量；“-”表示低于检测限 
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表 2 电气石样品测试点的经验结构公式及所属电气石亚种类型
Table 2 Empirical structural formula for testing points of tourmaline samples and their corresponding types of tourmaline subspecies
样品号 化学式 亚种 TS-1-A (Na0.47Ca0.49K0.01□0.04)(Mg1.60Al0.82Cr0.53V0.01Ti0.02)3(Al4.85Mg1.15)6(Si6O18)(BO3)3(OH)3.27O0.73 Uvite Ca-Mg-O root name TS-1-B (Na0.49Ca0.46K0.01□0.04)(Mg1.58Al0.84Cr0.50V0.01Ti0.03)3(Al4.87Mg1.13)6(Si6O18)(BO3)3(OH)3.21O0.79 Dravite Oxy-dravite TS-1-C (Na0.57Ca0.39K0.01□0.04)(Mg1.52Al0.85Cr0.52V0.01Ti0.03)3(Al4.88Mg1.12)6(Si6O18)(BO3)3(OH)3.20O0.80 Dravite Oxy-dravite TS-2-A (Na0.50Ca0.43K0.01□0.06)(Mg1.53Al0.86Cr0.52V0.01Ti0.03)3(Al4.90Mg1.10)6(Si6O18)(BO3)3(OH)3.18O0.82 Dravite Oxy-dravite TS-2-B (Na0.56Ca0.36K0.01□0.07)(Mg1.52Al0.86Cr0.55V0.01Ti0.03)3(Al4.90Mg1.10)6(Si6O18)(BO3)3(OH)3.28O0.72 Dravite Oxy-dravite TS-2-C (Na0.48Ca0.46K0.01□0.06)(Mg1.57Al0.83Cr0.56V0.01Ti0.02)3(Al4.87Mg1.13)6(Si5.99Al0.01O18)(BO3)3(OH)3.29O0.71 Dravite Oxy-dravite TS-3-A (Na0.49Ca0.45K0.01□0.05)(Mg1.44Al0.78Cr0.65V0.01Ti0.03)3(Al4.79Mg1.21)6(Si6O18)(BO3)3(OH)3.14O0.86 Dravite Oxy-dravite TS-3-B (Na0.59Ca0.34K0.01□0.06)(Mg1.28Al0.75Cr0.86V0.01Ti0.03)3(Al4.74Mg1.26)6(Si6O18)(BO3)3(OH)3.16O0.84 Dravite Oxy-dravite TS-4-A (Na0.52Ca0.39K0.01□0.08)(Mg1.66Al0.93Cr0.34V0.01Ti0.02)3(Al4.98Mg1.02)6(Si6O18)(BO3)3(OH)3.31O0.69 Dravite Oxy-dravite TS-4-B (Na0.54Ca0.39K0.01□0.05)(Mg1.54Al0.89Cr0.50V0.01Ti0.03)3(Al4.94Mg1.06)6(Si6O18)(BO3)3(OH)3.22O0.78 Dravite Oxy-dravite 注：数据结果仅显示两位小数；种类命名两列分别参考Tindle等和Henry等[5-6]
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[1] Haidinger W. Ueber den pleochroismus des chrysoberylls[J]. Annalen der Physik, 1849, 153(6): 228-236. doi: 10.1002/andp.18491530605
[2] Halvorsen A, Jensen B. A new colour-change effect[J]. The Journal of Gemmology, 1997, 25(5): 325-330. doi: 10.15506/JoG.1997.25.5.325
[3] Halvorsen A. The Usambara effect and its interaction with other colour change phenomena[J]. The Journal of Gemmology, 2006, 30(1/2): 1-21.
[4] Kennard T G, Howell D H. Types of coloring in minerals[J]. American Mineralogist, 1941, 26(7): 405-421.
[5] Webster R. Tanganyika tourmaline[J]. Gemmologist, 1961, 30: 41-54.
[6] Balitsky V S, Balitskaya O V. The amethyst-citrine dichromatism in quartz and its origin[J]. Physics and Chemistry of Minerals, 1986, 13(6): 415-421. doi: 10.1007/BF00309187
[7] Manson D, Stockton C. Pyrope-spessartine garnets with unusual color behavior[J]. Gems and Gemology, 1984, 20(4): 200-207. doi: 10.5741/GEMS.20.4.200
[8] Simonet C. Geology of the yellow mine (Taita-Taveta district, Kenya) and other yellow tourmaline deposits in east Africa[J]. The Journal of Gemmology, 2000, 27(1): 11-29. doi: 10.15506/JoG.2000.27.1.11
[9] Krzemnicki M S. Exceptional colour change garnets showing the Usambara effect[J]. Facette, 2014 (12): 16-17.
[10] Sun Z Y, Palke A C, Renfro N. Vanadium-and chromium-bearing pink pyrope garnet: Characterization and quantitative colorimetric analysis[J]. Gems and Gemology, 2015, 51(4): 348-369.
[11] Schmetzer K, Bernhardt H J, Balmer W A, et al. Synthetic alexandrites grown by the HOC method in Russia: Internal features related to the growth technique and colorimetric investigation[J]. The Journal of Gemmology, 2013, 33(5-6): 113-129.
[12] Sun Z Y, Palke A C, Muyal J, et al. How to facet gem-quality chrysoberyl: Clues from the relationship between color and pleochroism, with spectroscopic analysis and colorimetric parameters[J]. American Mineralogist, 2017, 102(8): 1 747-1 758. doi: 10.2138/am-2017-6011
[13] Liu Y, Shi G, Wang S. Color phenomena of blue amber[J]. Gems and Gemology, 2014, 50(2): 134-140.
[14] Masselot J. Le diamant noir polycristallin rencontré en joaillerie[D]. Nantes: Université de Nantes, 2014.
[15] Fritsch E, Rondeau B, Peclet T, et al. Red cordierite from Madagascar[J]. Gems and Gemology, 2016, 52(4): 97-98.
[16] Rondeau B, Chamard-Bois S, Fritsch E, et al. Reverse dichromatism in gem andalusite related to total pleochroism of the Fe2+-Ti4+ IVCT[J]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2018(204): 611-619.
[17] Fink W, Bednarik J, Schneider W. Visual dichroism in glasses[J]. Journal of Physics D: Applied Physics, 1975, 8(13): 1 560-1 566. doi: 10.1088/0022-3727/8/13/018
[18] Nassau K. The physics and chemistry of color: The fifteen causes of color[M]. 1st ed. New York: John Wiley & Sons, 1987.
[19] Clark W M, Lubs H A. The colorimetric determination of hydrogen ion concentration and its applications in bacteriology, part Ⅱ[J]. Journal of Bacteriology, 1917, 2(2): 109-136. doi: 10.1128/jb.2.2.109-136.1917
[20] Bamford C R. Colour generation and control in glass (glass science and technology 2)[M]. 1st ed. Amsterdam: Elsevier Science Ltd., 1977.
[21] Webster R. Gems : Their sources, descriptions, and identification[M]. 1st ed. London: Butterworths, 1962.
[22] Kreft S, Kreft M. Physicochemical and physiological basis of dichromatic colour[J]. Naturwissenschaften, 2007, 94(11): 935-939. doi: 10.1007/s00114-007-0272-9
[23] Li Z, Hu Z, Liu Y, et al. Accurate determination of elements in silicate glass by nanosecond and femtosecond laser ablation ICP-MS at high spatial resolution[J]. Chemical Geology, 2015(400): 11-23.
[24] Liu Y, Hu Z, Gao S, et al. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257(1-2): 34-43. doi: 10.1016/j.chemgeo.2008.08.004
[25] Sun Z Y, Palke A C, Breeding C M, et al. A new method for determining gem tourmaline species by LA-ICP-MS[J]. Gems and Gemology, 2019, 55(1): 2-17.
[26] Henry D J, Novák M, Hawthorne F C, et al. Nomenclature of the tourmaline-supergroup minerals[J]. American Mineralogist, 2011, 96(5-6): 895-913. doi: 10.2138/am.2011.3636
[27] Tindle A G, Breaks F W, Selway J B. Tourmaline in petalite-subtype granitic pegmatites: Evidence of fractionation and contamination from the Pakeagama Lake and Separation Lake areas of northwestern Ontario, Canada[J]. The Canadian Mineralogist, 2002, 40(3): 753-788. doi: 10.2113/gscanmin.40.3.753
[28] Henry D J, Dutrow B L. Metamorphic tourmaline and its petrologic applications[J]. Reviews in Mineralogy, 1996, 33(1): 503-557.
[29] Pesquera A, Gil-Crespo P P, Torres-Ruiz F, et al. A multiple regression method for estimating Li in tourmaline from electron microprobe analyses[J]. Mineralogical Magazine, 2016, 80(6): 1 129-1 133. doi: 10.1180/minmag.2016.080.046a
[30] Bosi F, Skogby H, Lazor P, et al. Atomic arrangements around the O3 site in Al-and Cr-rich oxy-tourmalines: A combined EMP, SREF, FTIR and Raman study[J]. Physics and Chemistry of Minerals, 2015, 42(6): 441-453. doi: 10.1007/s00269-015-0735-z
[31] Hawthorne F C, MacDonald D J, Burns P C. Reassignment of cation site occupancies in tourmaline: Al-Mg disorder in the crystal structure of dravite[J]. American Mineralogist, 1993, 78(3-4): 265-270.
[32] Grice J D, Ercit T S. Ordering of Fe and Mg in the tourmaline crystal structure: The correct formula[J]. Neues Jahrbuch für Mineralogie Abhandlungen, 1993, 165(3): 245-266.
[33] Bosi F, Lucchesi S, Reznitskii L. Crystal chemistry of the dravite-chromdravite series[J]. European Journal of Mineralogy, 2004, 16(2): 345-352. doi: 10.1127/0935-1221/2004/0016-0345
[34] Cempirek J, Houzar S, Novak M, et al. Crystal structure and compositional evolution of vanadium-rich oxy dravite from graphite quartzite at Bítovánky, Czech Republic[J]. Journal of Geosciences, 2013, 58(2): 149-162.
[35] Bosi F. Tourmaline crystal chemistry[J]. American Mineralogist, 2018, 103(2): 298-306. doi: 10.2138/am-2018-6289
[36] 张良钜. 碧玺的宝石学特征[J]. 桂林工学院学报, 1996, 16(3): 291-297. https://www.cnki.com.cn/Article/CJFDTOTAL-GLGX603.018.htm Zhang L J. Gemmological characterisitics of tourmalines[J]. Journal of Guilin Institute of Technology, 1996, 16(3): 291-297. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GLGX603.018.htm
[37] 李雯雯, 吴瑞华, 董颖. 电气石红外光谱和红外辐射特性的研究[J]. 高校地质学报, 2008, 14(3): 426-432. doi: 10.3969/j.issn.1006-7493.2008.03.014 Li W W, Wu R H, Dong Y. Study on infrared spectra and infrared radiation characteristics of tourmaline[J]. Geological Journal of China Universities, 2008, 14(3): 426-432. (in Chinese) doi: 10.3969/j.issn.1006-7493.2008.03.014
[38] 汤云晖. 电气石的表面吸附与电极反应研究[D]. 北京: 中国地质大学, 2003. Tang Y H. Tourmaline's surface absorption and its electrode reaction research[D]. Beijing: China University of Geosciences, 2003. (in Chinese)
[39] 袁婷. 同一方向碧玺的红外光谱谱学特征[J]. 超硬材料工程, 2008, 20(6): 57-60. https://www.cnki.com.cn/Article/CJFDTOTAL-ZBKJ200806019.htm Yuan T. IR spectral characteristics of tourmalines with the same direction[J]. Superhard Material Engineering, 2008, 20(6): 57-60. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-ZBKJ200806019.htm
[40] 田甜, 王以群, 蔡灵婷, 等. 热处理对阿富汗黄绿色和粉色碧玺颜色的改善[J]. 华东理工大学学报(自然科学版), 2019, 45(3): 402-410. https://www.cnki.com.cn/Article/CJFDTOTAL-HLDX201903007.htm Tian T, Wang Y Q, Cai L T, et al. Heat treatment for color improvement of yellow-green and pink tourmalines from Afghanistan[J]. Journal of East China University of Science and Technology, 2019, 45(3): 402-410. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-HLDX201903007.htm
[41] 孙麟, 杨明星, 吴改. 近期市场出现的铬碧玺宝石学性质及谱学特征[J]. 宝石和宝石学杂志(中英文), 2015, 17(1): 31-37. https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB201501005.htm Sun L, Yang M X, Wu G. Gemmological and spectroscopic characteristics of chrome tourmaline appeared on the market recently[J]. Journal of Gems & Gemmology, 2015, 17(1): 31-37. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB201501005.htm
[42] 廖秦镜, 黄伟志, 张倩, 等. 莫桑比克棕黄色碧玺的宝石学及光谱学表征[J]. 光谱学与光谱分析, 2019, 39(12): 3 844-3 848. https://www.cnki.com.cn/Article/CJFDTOTAL-GUAN201912037.htm Liao Q J, Huang W Z, Zhang Q, et al. Gemological and spectral characterization of brownish yellow tourmaline from Mozambique[J]. Spectroscopy and Spectral Analysis, 2019, 39(12): 3 844-3 848. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-GUAN201912037.htm
[43] Mauro D, Biagioni C, Hålenius U, et al. Nickel- and Fe3+-rich oxy-dravite from the Artana Mn prospect, Apuan Alps (Tuscany, Italy)[J]. Journal of Geosciences, 2022, 67(2): 141-150.
[44] Nasdala L, Wildner M, Giester G, et al. Blue dravite ('Indicolite') from the Elahera gem field, Sri Lanka[J]. The Journal of Gemmology, 2021, 37(6): 618-630.
[45] Taran M N, Lebedev A, Platonov A. Optical absorption spectroscopy of synthetic tourmalines[J]. Physics and Chemistry of Minerals, 1993, 20(3): 209-220.
[46] Ertl A, Rossman G R, Hughes J M, et al. V3+-bearing, Mg-rich, strongly disordered olenite from a graphite deposit near Amstall, Lower Austria: A structural, chemical and spectroscopic investigation[J]. Neues Jahrbuch für Mineralogie Abhandlungen, 2007, 184(3): 243-254.
[47] Mazurak Z, Czaja M. Optical properties of tsavorite Ca3Al2(SiO4)3∶Cr3+, V3+ from Kenya[J]. Journal of Luminescence, 1995, 65(6): 335-340.
[48] 邵天, 陈超洋, 黄伟志, 等. 绿色蓝晶石的宝石学特征[J]. 宝石和宝石学杂志(中英文), 2020, 22(2): 12-19. https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB202002002.htm Shao T, Chen C Y, Huang W Z, et al. Gemmological characteristic of green kyanite[J]. Journal of Gems & Gemmology, 2020, 22(2): 12-19. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB202002002.htm
[49] 姚心言. Cr3+掺杂的氧化物荧光粉的制备及光谱特性研究[D]. 昆明: 云南师范大学, 2020. Yao X Y. Preparation and spectrum property of Cr3+ doped oxide phosphors[D]. Kunming: Yunnan Normal University, 2020. (in Chinese)
[50] 李立平, 业冬. 铬和钒在宝石变色效应中的作用[J]. 宝石和宝石学杂志(中英文), 2003, 5(4): 17-21. https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB200304004.htm Li L P, Ye D. Role of Cr and V in colour change effect of gemstones[J]. Journal of Gems & Gemmology, 2003, 5(4): 17-21. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB200304004.htm
[51] Gaft M, Reisfeld R, Panczer G. Modern luminescence spectroscopy of minerals and materials[M]. 2nd ed. Berlin: Springer, 2015.
[52] Xin C, Li Y, Wang Y, et al. Characterisation of patchy blue and green colouration in Dominican blue amber[J]. The Journal of Gemmology, 2021, 37(7): 702-715.
[53] 胡贺文, 李妍. 缅甸"变色龙"琥珀特殊颜色现象成因初探[J]. 宝石和宝石学杂志(中英文), 2023, 25(4): 99-110. https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB202304014.htm Hu H W, Li Y. The cause of the special colour phenomenon of "Chameleon" amber from Myanmar[J]. Journal of Gems & Gemmology, 2023, 25(4): 99-110. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-BSHB202304014.htm
[54] Tang J, Guo Y, Zhang J. Colorimetry characteristics and color contribution of fluorescence in natural Cr-containing spinel[J]. Scientific Reports, 2023, 13(1): 2 426.
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