Based on previous studies of kimberlite xenoliths and diamond inclusions in this region, macrocrystai garnet was analyzed with the electric microprobe technique （EPMA）. The garnet is collected from the Shengli No.1 ...Based on previous studies of kimberlite xenoliths and diamond inclusions in this region, macrocrystai garnet was analyzed with the electric microprobe technique （EPMA）. The garnet is collected from the Shengli No.1 kimberlite pipe in the Mengyin area of Shandong Province, China. The results indicate that the garnet contains two kinds of multiphase inclusions： one is K-, B-, and CI- bearing oxygen-free phase, K- and Cl-bearing oxygen-free phase, and volatile-bearing garnet inclusions （in1 and in3）; and the other is chlorite, phlogopite, apatite and calcite （in2）. It is suggested that the formation of garnet and its inclusions is associated with strongly reduced mantle fluid. Such a fluid was transformed from ultra-deep high-reduction oxygen-free fluid into low-reduction alkaline fluid, and finally into oxidized fluid with low oxygen fugacity. This result confirms that the Mengyin area underwent metamorphism of slightly active deep fluid, and provides evidence for searching diamond by means of indicative minerals.展开更多
A light purplish red sapphire is heat treated in an airtight crucible. The sample changes little in color after receiving heat treatment at 1100℃, but turns to light blue and blue after being treated at 1200℃ and 1...A light purplish red sapphire is heat treated in an airtight crucible. The sample changes little in color after receiving heat treatment at 1100℃, but turns to light blue and blue after being treated at 1200℃ and 1300℃, respectively. Before heating, the UV-VIS absorption spectra of the sample are dominated by the 551 nm broad absorption band contributed by the d-electron transition 4A2 →4 4T2 of Cr3＋. After heating, the UV-VIS absorption spectra are dominated by the 563 nm broad absorption band contributed by the inter- valence charge transfer of Fe2＋ - Ti4＋. The x ray photoelectron spectroscopy test reveals that the Fe2＋ and Ti4＋ ion contents increase with increasing temperature. The sapphire changing from light purplish red to blue in the heating process is owing to the fact that the Fe2＋ and Ti4＋ contents grow and the intervalence charge transfer of Fe2＋ - Ti4＋ selectively absorbs UV-VIS light.展开更多
Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrario...Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrariolet-visible-near-infrared （UV-VIS NIR） spectral analyses in combination with annealing ex- periments, the color center of tourmaline is found to be related to the d - d transitions of ions or the d - d transitions of exchange coupled ions. Annealing crystMs treatment affects the color improvement of tourmaline展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 4027301)the National Geological Survey Project (Grant No.003201)
文摘Based on previous studies of kimberlite xenoliths and diamond inclusions in this region, macrocrystai garnet was analyzed with the electric microprobe technique （EPMA）. The garnet is collected from the Shengli No.1 kimberlite pipe in the Mengyin area of Shandong Province, China. The results indicate that the garnet contains two kinds of multiphase inclusions： one is K-, B-, and CI- bearing oxygen-free phase, K- and Cl-bearing oxygen-free phase, and volatile-bearing garnet inclusions （in1 and in3）; and the other is chlorite, phlogopite, apatite and calcite （in2）. It is suggested that the formation of garnet and its inclusions is associated with strongly reduced mantle fluid. Such a fluid was transformed from ultra-deep high-reduction oxygen-free fluid into low-reduction alkaline fluid, and finally into oxidized fluid with low oxygen fugacity. This result confirms that the Mengyin area underwent metamorphism of slightly active deep fluid, and provides evidence for searching diamond by means of indicative minerals.
文摘A light purplish red sapphire is heat treated in an airtight crucible. The sample changes little in color after receiving heat treatment at 1100℃, but turns to light blue and blue after being treated at 1200℃ and 1300℃, respectively. Before heating, the UV-VIS absorption spectra of the sample are dominated by the 551 nm broad absorption band contributed by the d-electron transition 4A2 →4 4T2 of Cr3＋. After heating, the UV-VIS absorption spectra are dominated by the 563 nm broad absorption band contributed by the inter- valence charge transfer of Fe2＋ - Ti4＋. The x ray photoelectron spectroscopy test reveals that the Fe2＋ and Ti4＋ ion contents increase with increasing temperature. The sapphire changing from light purplish red to blue in the heating process is owing to the fact that the Fe2＋ and Ti4＋ contents grow and the intervalence charge transfer of Fe2＋ - Ti4＋ selectively absorbs UV-VIS light.
文摘Tourmaline is an important functional and gem material. The current study examines pink, green, and brownish-green tourmalines from Altay deposit. Based on X-ray fluorescence （XRF） quantitative analyses and ultrariolet-visible-near-infrared （UV-VIS NIR） spectral analyses in combination with annealing ex- periments, the color center of tourmaline is found to be related to the d - d transitions of ions or the d - d transitions of exchange coupled ions. Annealing crystMs treatment affects the color improvement of tourmaline
