The allusions of the luminous pearls of past dynasties have left endless suspense for the world. Nowadays, the fluorite luminous pearl attracts people's attention, because it has already left a deep impression on people's hearts, so it has formed a series of reports in the news and online media, and commercial speculation luminous pearl has also made an amazing bid. Not long ago, a natural grandmother's green fluorite luminous pearl weighing 5 kilograms actually set a sky-high price of several hundred million yuan, which caused a sensation in the market for a while. Is the fluorite night pearl really worth that much money?
The continuous discovery and increasing variety of the night pearl enrich the nothingness and practical connotation of the night pearl, which will gradually open the door to its eternal mystery.
In the process of testing these samples, the author made a detailed mineralogical study and identification of luminous mineral raw materials (mainly fluorite) for processing spheres.
2. The eternal mystery of the night pearl
The night pearl is a wonderful pen for writers of all ages to write articles. Emperors of all ages believed that owning the luminous pearl was a symbol of power. Empress Dowager Cixi died with a pearl in her eye and will accompany her forever. For a long time, the night pearl, like a misty cloud, has built an eternal mystery for future generations to comment on.
The most basic feature of the night pearl recorded in historical materials is that it emits bright light in the dark. So, what exactly is such a substance? According to analysis, there are minerals, rocks, mussels, snails, pearls and various creatures here. The mechanism of luminescence is the transformation of internal energy, such as the decay process of chemical elements, and the change of internal structure caused by the excitation of external energy.
Second, the historical evolution of The Night Pearl
China enjoys three rare treasures and enjoys a good reputation at home and abroad. They are ancient luminous pearls (Sui Ball, Hanging Plum and Hanging Spine), Jingshan of Chu State, Shibi and Xiliang luminous cup.
"History of Han Zou Yang Chuan" "The pearl of the bright moon comes from rivers and seas, hides in mussels and crouches in them". "Luminous" in Dong Fangshuo's Ten States in the Sea in the Western Han Dynasty. In the Eastern Han Dynasty, Notes on Sui Dynasty and Night Pearl after Sui Dynasty were circulated.
The "Luminous Jade" in Li Si's "Zhuke Shu" in Qin Dynasty. In Qin's Biography of the Western Regions and the Great State of Qin, "there are many treasures of gold and silver, and the luminous jade is also a pearl at night".
In the palace of Emperor Xuanzong of the Tang Dynasty, there was a "jade mouse with a bright night". In the poem "Liangzhou Ci" written by Wang Hanfu, a poet in the Tang Dynasty, there is a luminous glass of grape wine. If you want to drink pipa, you must be urged immediately, and you can't laugh when you are drunk in the battlefield. How many times did you play in ancient times? " .
Shen Kuo in the Northern Song Dynasty wrote in Meng Qian Bi Tan that he cooked salted duck eggs at night in Haizhou in his early years, during which an egg was as bright as jade, which lit up the room. "In the container for more than ten days, smell and decay are exhausted, and the more obvious.
In the Yuan Dynasty, there was the Pearl of Kowloon written by Genghis Khan.
Empress Dowager Cixi handed down the saying that "the phoenix crown is inlaid with nine pearls".
During the Republic of China, the warlord Sun Dianying robbed the tomb and stole the pearls of Empress Dowager Cixi. It is said that Song Meiling, Chiang Kai-shek's wife, nailed these slippers with a luminous pearl.
Liang Yusheng, a modern writer, wrote The Nineteenth Time: I heard a faint sigh in the drum. Geng Zhao touched her body and said, I didn't send anything to Sang Qinghong, but she did send me something. That's the night pearl, and I don't want her either. It was only at that time that I was imprisoned in a grotto, and I could only practice the Eight-Shaped Great Yan on the stone wall by its brilliance, and then put it on it casually.
Third, the reason why the luminous pearl shines.
1, luminescence of minerals
The property that minerals produce visible light under the excitation of external energy is called mineral luminescence. External energy includes sunlight, ultraviolet rays, X-rays, cathode rays, heating, pressure, friction and so on. According to different luminescent properties, it can be divided into two categories: fluorescence and phosphorescence.
2. Fluorescence of minerals
Minerals continuously emit light under the continuous excitation of external energy. When the excitation of external energy stops, the phenomenon of mineral luminescence disappears immediately, which is called mineral fluorescence.
3. Phosphorescence of minerals
Minerals emit light under the excitation of external energy, and when the excitation of external energy stops, the phenomenon of minerals emitting light remains for a period of time, which is called phosphorescence of minerals.
4. Mineral luminescence mechanism
The luminescence of minerals is a transformation process of mineral energy. When the lattice in the mineral crystal structure absorbs a certain amount of external energy, it is released by luminescence.
The mechanism of fluorescence is that the outer electrons of atoms or ions in mineral crystal structure are excited from the ground state to the excited state with higher energy for ultraviolet rays, X rays, gamma rays and infrared rays with energy higher than that of visible light. When there are other excited States between the excited state and the ground state, the electrons excited to the excited state with higher energy fall back to the excited state with lower energy, so photons are emitted. When the energy difference between two excited states is equivalent to the energy difference of one photon.
Mechanism of phosphorescence: For some mineral crystal structures, the excited electrons can be captured by crystal defects or the forbidden band in electron configuration. If it is temporary, the excited electrons still fall back to the ground state at a certain speed, so they continue to emit light when the external excitation energy stops, and slowly decay to form phosphorescence.
Thermoluminescence effect: there is an energy barrier in the mineral crystal structure, which can inhibit the excited electrons from falling back to the ground state. When the excited electrons are suppressed, they are activated by heat, thus breaking through the energy barrier, falling back to the ground state, emitting visible light and forming thermoluminescence effect.
Luminescence effect of compressive stress: under the action of compressive stress, the crystal lattice of minerals is destroyed and deformed. When external excitation energy acts, minerals release energy in the form of luminescence.
Four, fluorescent minerals and phosphorescent minerals
1, fluorescent minerals and fluorescent colors
The same fluorescent mineral may not be fluorescent due to the difference of crystal internal structure, but it may also show fluorescent colors with different tones and intensities.
Minerals that emit light under ultraviolet light and their fluorescent colors are as follows:
Fluorite (purple, sky blue and milky white), barite (purple, yellow and rose), diamond (purple, sky blue and yellow green), sphalerite (red), zircon (yellow), scheelite (sky blue), dolomite (orange red and yellow) and apatite (purple, rose and red). Wurtzite (purple, light yellow), wollastonite (yellow), serpentine (yellow), corundum (purple, red), potassium nitrate (dark yellow), hemimorphite (light purple, yellow), potassium vanadate (bright yellow-green), lepidolite (green-white), magnesite (yellow) and microcline (plagioclase). Prehnite (red), andalusite (orange, yellow), galena (bright green), chabazite (red), spinel (crimson), barium calcium carbonate (yellow), Yellow River mine (red yellow), borohydride (ivory), amber (red yellow, light turquoise, blue white) and coral (ivory white).
The luminescent minerals and fluorescent colors under X-ray are as follows:
Lead alum (sky blue), apatite (yellow, green and sky blue), diamond (sky blue), alunite (yellow), albite (blue), barite (green), beryl (yellow), wollastonite (yellow and purple), dolomite (rose), calcite (rose) and halite.
The luminescent minerals and fluorescent colors under cathode ray are as follows:
Lead alum (sky blue), apatite (yellow, green and red), aragonite (rose red), asbestos (yellow and rose red), diamond (yellow, rose red and sky blue), actinolite (yellow), ettringite (red), alunite (purple) and albite (purple and white). Kyanite (red), serpentine (red), calcite (light red and orange red), cancrinite (rose and white), Yingshi (blue, rose and purple), corundum (red and sky blue), potassium nitrate (red), hemimorphite (sky blue and green) and kaolinite (sky blue). Sanidine (light yellow), andalusite (rose), sphalerite (red), siderite (red), stellite (red, sky blue), tourmaline (red), tremolite (yellow-green, purple), talc (red), topaz (sky blue), phosphorite (yellow), anorthite.
2. Characteristics of phosphorescent minerals
The same phosphorescent mineral may not be phosphorescent due to the difference of crystal internal structure, but it may also present phosphorescent colors with different tones and intensities. Minerals with phosphorescence must also have fluorescence, but minerals with fluorescence may not necessarily have phosphorescence.
1), fluorite
Phosphorescence: milky white, light purple, light blue and white. Excitation energy: sunlight, ultraviolet ray, X ray, cathode ray, heat, hot water bath, friction. Crystal system: equiaxed crystal system. Shape: cube, rhombic dodecahedron, octahedron, hexahedron, hexahedron, irregular granule. Chemical composition: CaF2. Colors: purple, green, blue, yellow, red, white and black. Optical characteristics: homogeneity. Cleavage: {11} complete. Refractive index: N 1.434 Gloss: glass luster. Mohs hardness: 4 Density: 3. 18g/cm3.
2) Scheelite
Phosphorescence: milky white, light blue white. Excitation energy: sunlight, ultraviolet ray, X ray, cathode ray, mechanical heat. Crystal system: tetragonal crystal system morphology: tetragonal biconical, plate-like, irregular granular. Chemical composition: Ca[WO4] Color: light purple, light green, light yellow, light reddish brown, white light Features: uniaxial orthography: {11} Medium refractive index: No1.920ne1.
3) apatite-apatite
Phosphorescence: milky white, light purple and light yellow. Excitation energy: sunlight, ultraviolet rays, hot water bath, heat, friction. Morphology: hexagonal biconical, hexagonal columnar, tabular and irregular granular crystal system: hexagonal crystal system Chemical composition: Ca2Ca3[PO4]3(OHF) Color: lavender, green, yellowish green, reddish brown, white light characteristics: uniaxial negative photocleavage: {000 1} Incomplete refractive index: No.655.
Note: When lanthanum group elements (La La, Ce Ce, Pr, Nd, Ju Pm, Sm Eu, Gadolinium Gd, Tb, Dy, Ho, Er, Tm, Yb, ⅵ) are used in phosphate minerals of calcium.
4), sphalerite
Phosphorescence: milky white, light purple excitation energy: sunlight, ultraviolet, heat. Morphology: tetrahedron, cube, rhombic dodecahedron, irregular granular crystal system: equiaxed crystal system Chemical composition: ZnS color: purplish red, light yellow brown, beige red, green and brown. Optical characteristics: homogeneous cleavage: {1 10} Complete refractive index: N2.37―2.47 luster: semi-metallic luster, diamond luster Mohs hardness: 3―4 density: 4.0g/cm3.
5) Diamonds
Phosphorescence: light blue, light blue excitation energy: sunlight, ultraviolet ray, X ray, cathode ray. Crystal system: equiaxed crystal system Chemical composition: C color: orange, green, blue, yellow, red, white and black. Optical characteristics: Homogeneity, often heterogeneous cleavage: {11} Medium refractive index: N2.4―2.48 luster: Mohs hardness of diamond luster.
6) carboboride
Phosphorescence: milky white, light green excitation energy: sunlight, ultraviolet rays, X-rays. Crystal system: monoclinic crystal system morphology: columnar and irregular granular chemical composition: mgca2 [hco3] [b (oh) 4] 2 (oh) 2 2h2o color: colorless, transparent, gray, white and brown. Optical properties: the biaxial crystal has negative optical properties, 2v = 75 cleavage: {10/kloc-0} complete refractive index: Ng= 1.569, Nm= 1.546, Np= 1.507 luster.
7) Kurna coesite in reservoir water.
Phosphorescence: milky white, light green excitation energy: sunlight, ultraviolet rays, X-rays. Crystal system: Tripartite crystal system Morphology: thick plate, irregular granular chemical composition: Mg (H2O) 5 [B2O3 (OH) 5] Color: colorless, transparent, blue, yellow, red, white and black. Optical properties: biaxial crystal is negative, 2v = 80 cleavage: {0 1 1.
8) petalite, petalite
Phosphorescence: milky blue and white excitation energy: sunlight, heat and friction. Crystal system: monoclinic crystal system morphology: plate, needle, irregular granular. Chemical composition: plum [AlSi4O 10] color: brown, yellow, red, green and white. Optical properties: biaxial crystal is positive, 2v = 82-84 cleavage: {00 1} complete refractive index: ng =1.516-1.523, nm =1.5/kl.
9), andalusite.
Phosphorescence: milky white. Excitation energy: sunlight, ultraviolet rays, heat. Crystal system: tetragonal crystal system Chemical composition: (naca) 4 [Al (Alsi) Si2O3] 3 (Cl, F, OH, CO3, SO4) Color: gray, navy blue, white. Optical properties: uniaxial crystals have negative optical properties. Cleavage: {100} medium. Refractive index: ne = 1.540- 1.562, no = 1.546- 1.600 luster: glass luster Mohs hardness: 5-6 density: 2.50-2.78g/cm3.
10), norbornite
Phosphorescence: milky white excitation energy: sunlight, heat. Crystal system: chemical composition: Ca(H2O)2[B3B3O9(OH)2] color: light yellow, white. Optical characteristics: uniaxial crystal positive light. Cleavage: {100} Complete refractive index: Ng= 1.555, Nm= 1.52 1, Np= 1.50 1 luster: Mohs hardness of glass luster:.
1 1)
Phosphorescence: milky white. Excitation energy: sunlight, friction. Crystal system: orthogonal crystal system Chemical composition: NaCa[BeSi2O6F] Color: green, yellow and white. Optical properties: biaxial crystals have negative optical properties. 2v = 39-40 cleavage: {11} Complete refractive index: ng = 1.596- 1.589, nm =1.595-
12), dense topaz chalcopyrite
Phosphorescence: milky white. Excitation energy: sunlight, friction. Crystal system: tetragonal crystal system Chemical composition: NaCa[BeSi2O6F] Color: yellow, reddish brown. Optical properties: uniaxial crystals have negative optical properties. Cleavage: {11} complete refractive index: No= 1.6 12, Ne= 1.593 glossiness: glass luster Mohs hardness: 5-5.5 density: 3.
3, artificial mineral raw materials
1), Qinglong luminescent synthetic gem
The phosphorescence afterglow is 1 1570mcd/m2 (the test object is excited for 0.5 hour under a 27-watt fluorescent lamp after hiding for 24 hours), and the phosphorescence colors are green, blue, yellow and purple.
2) Fluorescent coating
Coating treatment of phosphor-free surface fluorescent coating.
Detection and evaluation of verb (verb abbreviation) night pearl
1, ultraviolet fluorescence intensity
Ultraviolet fluorescence intensity is divided into strong (eye-catching), medium (general) and weak (dim).
2. Phosphorescence brightness (brightness)
Phosphorescence brightness is the afterglow of phosphorescence per square meter, which is represented by the symbol mcd/m2.
Phosphorescence brightness is proportional to the volume of the luminous object. The same luminous object is strong when it is big and weak when it is small.
According to legend, the phosphorescence brightness in ancient candlelight was 1 square foot, and it was best to look at millet, mung bean and soybean on average.
3. Phosphorescence color
The color of phosphorescence is mainly milky white, but there are also pink, light purple, light blue and light yellow.
4. Phosphorescence delay
Phosphorescence delay means that the luminous object is placed in a dark environment (darkroom) for 24 hours and excited for 10 hour. The excitation sources are mainly sunlight, ultraviolet rays and heat, but there are also X-rays, cathode rays and pressure. When the afterglow attenuation is zero, the value of time length is judged. >; 10 hour is excellent, 4- 10 hour is good, and 0.5-4 is average.
5. Comprehensive evaluation method
Mineral evaluation includes mineral color brightness, mineral transparency, single crystal or aggregate, and occurrence probability of minerals in nature.
Luminous evaluation, including the brightness and luminous color of the night pearl, in which the color is the best, followed by milky white and phosphorescence delay length.
Process evaluation, including size, roundness, surface polishing, treatment, etc.
Historical and cultural connotations, including the origin, dynasties, varieties and allusions of the night pearl.
Six, the night pearl detection example
1, an example of the night pearl.
Inspection number: BL112911,shape: spherical, color: yellow, green, white and green, total mass: 165.9g, refractive index: 1.438, optical characteristics:. Conclusion: Fluorite.
2. The second example of the night pearl
Sample number: BL2020365, mass: 12525g, shape: spherical. Color: light green, green, dark green, luster: glass luster, luster: isotropic, density: 3. 18 (counting) g/cm3, refractive index: 1.435, Mohs hardness: 4, fluorescence: purple long, short-wave display uneven purple, sky blue fluorescence. Structure: Semi-self-shaped granular crystal mosaic structure with complete development of mineral cleavage. Mineral composition: fluorite hemimorphic particles > 98%, calcite particles.
3. Example of luminous pearl decorative gemstone
Sample number: BL2060004, shape: stone, color: green, dark green, luster: glass luster, gloss: isotropic, density: 3. 15g/cm3, refractive index: 1.440, Mohs hardness: 4; Transparency: translucent, fluorescence: purple is long, short wave shows strong purple blue-white fluorescence, phosphorescence: light blue-white phosphorescence. Structural structure: semi-autogenous megacrysts, coarse-grained mosaic structure, banded structure and fully developed mineral cleavage. Chemical composition: CaF2:98%, mineral composition: fluorite semi-automorphic granular crystals >: 99%, calcite particles.
Seven. Mineral geology of Ye Ming
1, fluorite luminous mineral occurrence geology
1), Zhaheba fluorite mine, Fuyun County, Xinjiang.
Produced in limestone, the upper surrounding rock contains strong silicification and kaolin, and the lower part contains sericitization. The thickness of the ore body is between 0.5 and 2.0 meters, and it is in continuous vein shape, locally in lenticular shape, and the vein length is about 40 meters. Fluorite single crystals are mostly cubic, and the aggregate is massive. Fluorite at the edge of ore body is purple or light purple white; The fluorite in the middle of the ore body is dark green. * * * Primary minerals include calcite and calcite, belonging to low-temperature hydrothermal deposits.
2) Dachang fluorite ore field in Guizhou.
The estimated reserves are 2-3 million tons, and the main mining areas are Bikang, northern Houpo, southern Houpo and Shajiaping.
Bikang Mining Area: Fluorite occurs in Maokou limestone at the top of Maokou Formation of Lower Permian. On the karst unconformity surface of Maokou limestone, the overlying strata are sandstone shale facies of Longtan coal measures of Upper Permian, and fluorite is produced along the strata. The pulse 1 is 800m long, 200m wide and1-1.7m thick. No.2 pulse is 1 10m long, 50m wide and 2. 1m thick. Associated minerals are Yingshi, calcite, hydromica and kaolinite. Belonging to a low-temperature hydrothermal stratabound fluorite deposit.
North and South of Houpo and Shajiaping Mining Areas: Fluorite occurs in Maokou limestone at the top of Maokou Formation of Lower Permian. On the karst unconformity surface of Maokou limestone, the overlying strata are altered basalt, tuff and tuffaceous glutenite facies at the bottom of Lower Permian Emeishan basalt, and the associated minerals are stibnite, quartz, calcite, hydromica, kaolinite, limonite and dolomite. It belongs to a low-temperature hydrothermal stratabound stibnite-fluorite deposit.
3) Zhejiang fluorite deposit
It occurs in rhyolite and rhyolite tuff of acid volcanic rock series, and has huge veins and convex mirrors. Fluorite has high transparency, bright color and some phosphorescence. Associated minerals include quartz, kaolinite, calcite, pyrite, galena and sphalerite. It belongs to volcanic low-temperature hydrothermal deposit.
2. Geological occurrence of apatite luminous minerals
1), sedimentary apatite deposits: China is rich in sedimentary apatite (phosphorite) deposits, which are known as "Sanyang Kaitai", namely Kunyang in Yunnan, Kaiyang in Guizhou and Liuyang in Hunan. Taking Guizhou mines as an example, the reserves of phosphate rock formed by biochemical deposition in Doushantuo period of late Sinian are 423 million tons in Kaiyang mining area, 4.555 billion tons in Baiyan mining area and 423 million tons in Gaoping mining area. Phosphate rocks were formed in biochemical deposits in Meishucun period of Lower Cambrian, and the reserves of new yttrium-bearing phosphate rocks reached 900 million tons. The mineral components are fluorapatite and carboapatite, which crystallize into fine aggregate, and dolomite calcite, glauconite, Yingshi, kaolinite and limonite are distributed.
2) Magmatic apatite: In plagioclase of basic rocks and syenite of alkaline rocks, apatite can be used as the main mineral to form magmatic apatite deposits. In granite pegmatite, muscovite pegmatite, biotite pegmatite and potassium pegmatite, apatite can form columnar transparent crystals of several tens centimeters.
3. Luminous mineral geology of scheelite
1), contact metasomatic scheelite deposit: skarn type and scheelite disseminated in the contact metamorphic zone outside granite and marble, with associated minerals such as pyrrhotite, pyrite, sphalerite, molybdenite, bismuthite, arsenopyrite and galena, such as skarn scheelite in Yaogang County, Hunan Province.
2) Scheelite chronological pulse: Scheelite and wolframite are dispersed in chronological pulse, and scheelite and wolframite can form coarse crystals and crystal clusters.
3) High-medium temperature hydrothermal filling deposit: sulfide scheelite-wolframite deposit, which occurs in the contact zone between quartz porphyry and sandstone, such as Guangdong; Reticular dacite-skarn composite tungsten-molybdenum-bismuth deposit, such as Shizhuyuan mining area in Hunan Province.
4. Occurrence geology of sphalerite luminous minerals
L) skarn type: contact metasomatic skarn type.
2) High-medium temperature liquid type: Associated minerals include arsenopyrite, chalcopyrite, pyrite, white iron ore, pyrrhotite and Yingshi.
3) Medium temperature liquid type: associated mineral galena and corresponding time.
4) Low-temperature hydrothermal type: Associated minerals include galena, dolomite, barite, Yingshi and calcite.
5. Diamond luminous mineral geology
1), kimberlite type: Associated minerals include garnet, forsterite, phlogopite, chlorite, calcite, chrome spinel, chrome diopside, apatite, perovskite, chrome mica, limonite and hydromica.
2) K-Mg lamprophyre type: Associated minerals include K-Mg amphibole, leucite, Mg-Al garnet, forsterite, phlogopite, chlorite, apatite, perovskite, chromite and limonite.
3) Diamond placer: river placer such as Dingjiagang, Changde, Hunan, and coastal placer such as Pulandian, Liaoning.
6, water, carbon, boron, luminous mineral production geology
Inland salt lake deposits in arid areas are associated with minerals such as halite, ulexite, reservoir hydromagnesite, Indian stone, Zhangshishui magnesite and hydromagnesite.
7. Luminous mineral geology of magnesium borate in reservoir water
Inland boric acid salt lake facies deposits in arid areas are associated with bischofite, ulexite, reservoir bischofite, Zhangshi bischofite, bischofite, borax, calcite and hydromica.
8. Geology of Ye Ming minerals in sanidine.
It occurs in granite pegmatite, and its associated minerals are spodumene, caesium garnet, tourmaline, albite, albite, quartz, apatite and potash feldspar.
9. beryl luminous mineral geology
1), gas: well-developed andalusite crystal clusters in volcanic cracks.
2) Contact metasomatism: Acid rocks and alkaline rocks have contact metasomatism metamorphism with limestone and dolomite to form andalusite, and the associated minerals are garnet, diopside and apatite.
3) Metamorphic rock: It occurs in green schist (Shanxi Province), and the associated minerals are tourmaline, biotite and magnetite.
10, geological occurrence of luminous minerals.
It occurs in borate deposits and is the product of porphyrite change. The associated mineral is ulexite.
1 1, and the geological occurrence is beryl luminous mineral.
Nepheline syenite pegmatite: Associated minerals include dense feldspar, nepheline, orthoclase and apatite.
12, a compact feldspar luminous mineral in geology.
Nepheline syenite pegmatite: Associated minerals include amphibole, nepheline, orthoclase and apatite.
Business opportunities of luminous substances
1, optimization of mineral resources
Natural luminescent substances are scarce, and fluorite luminous pearl is excavated from fluorite mine. The problems that should be paid attention to in China's mining development, especially in the western region, can be compared to the relationship between selling rice or rice to achieve development and value-added purposes. The price of selling a ton of fluorite ore is around 200 yuan, and those that meet the requirements of technological fluorite are more valuable, generally ten times the price of ore.
According to the data currently available, fluorite is the best natural mineral for making luminous pearls, and fluorite is the only best raw material for making large luminous balls. China's fluorite reserves rank second in the world, second only to Mexico. Zhejiang, Guizhou and Xinjiang are the main producing areas of fluorite, and fluorite is also produced in Henan, Inner Mongolia, Guangdong and Hunan. When developing fluorite ore, we should improve the scientific and technological strength, pay attention to the comprehensive development and utilization of mining areas, seams, veins and ores with strong fluorescence and phosphorescence in fluorite, and avoid the loss of special resources in vain, because mineral resources are non-renewable.