本文選題：礦物組成 + 結(jié)構(gòu)�。� 參考：《中國(guó)地質(zhì)大學(xué)(北京)》2015年碩士論文

【摘要】：危地馬拉翡翠礦床位于北美—加勒比板塊碰撞帶內(nèi),原生礦床產(chǎn)于莫塔瓜河谷深斷裂帶南北兩側(cè)的白堊紀(jì)蛇紋巖帶之中,長(zhǎng)度可達(dá)200千米。南北兩側(cè)的硬玉巖在巖石組合、形成的溫度壓力條件和地質(zhì)年代等方面均有較大差別。本文在收集了危地馬拉常見的綠色系列翡翠(包括藍(lán)綠色、淺灰綠色、墨綠色)樣品的基礎(chǔ)上,運(yùn)用常規(guī)寶石學(xué)、薄片觀察、陰極發(fā)光、電子探針、X射線粉晶衍射、紫外—可見光光譜、紅外光譜等方法,對(duì)危地馬拉綠色系列翡翠典型樣品的基本寶石學(xué)性質(zhì)、結(jié)構(gòu)特征、礦物組成、化學(xué)成分、譜學(xué)特征及顏色成因等進(jìn)行研究。藍(lán)綠色翡翠,油脂光澤—玻璃光澤,微透明,折射率點(diǎn)測(cè)為1.66,相對(duì)密度3.22-3.31;斑狀變晶結(jié)構(gòu),疊加糜棱結(jié)構(gòu);礦物組成為綠輝石、硬玉、多硅白云母,少量褐簾石、榍石、金紅石、鋯石。淺灰綠色翡翠,油脂光澤—玻璃光澤,不透明,折射率點(diǎn)測(cè)為1.67-1.68,相對(duì)密度為3.26-3.30,可見“翠性”;碎裂結(jié)構(gòu),局部殘留柱粒狀鑲嵌結(jié)構(gòu);礦物組成為硬玉,少量黑云母、斜黝簾石。墨綠色翡翠,玻璃光澤,半透明,折射率點(diǎn)測(cè)為1.66,相對(duì)密度3.27-3.34;顯微變晶結(jié)構(gòu),疊加糜棱結(jié)構(gòu);礦物組成為綠輝石、硬玉,少量石榴石。藍(lán)綠色翡翠的紅外反射光譜主要顯示硬玉特征峰,主要峰值為1081 cm-1、954 cm-1、582 cm-1、524 cm-1、470 cm-1、435cm-1,;淺灰綠色翡翠與標(biāo)準(zhǔn)硬玉紅外光譜基本相同,主要峰值為1086 cm-1、954 cm-1、590 cm-1、534 cm-1、522 cm-1、471 cm-1、435 cm-1;墨綠色翡翠主要顯示綠輝石的紅外光譜,主要峰值為1064cm-1、961 cm-1、562 cm-1、521cm-1、455 cm-1、441 cm-1。藍(lán)綠色、淺灰綠色翡翠的紫外—可見光譜具有紫區(qū)434nm的吸收峰;墨綠色翡翠具有436nm處吸收峰及Cr3+引起的紅區(qū)693nm、670nm、656nm處吸收峰,使其在透射光下顯示純正的綠色。
[Abstract]:The Jade deposit in Guatemala is located in the collision zone between North America and the Caribbean plate. The primary deposit occurs in the Cretaceous ophiolite belt on the north and south sides of the Motagua valley deep fault zone, and its length can be up to 200 km. The jadeite rocks on both sides of north and south are different in rock assemblage, temperature and pressure conditions and geological age. On the basis of collecting the common green series of jadeite jade (including turquoise, light gray green, dark green) in Guatemala, conventional gemmology, thin slice observation, cathodic luminescence, electron probe X-ray powder diffraction are used in this paper. The basic gemstone properties, structural characteristics, mineral composition, chemical composition, spectral characteristics and color origin of typical samples of Guatemala green jadeite were studied by UV-Vis spectroscopy and infrared spectroscopy. Blue-green jadeite, greasy gloss-glass gloss, slightly transparent, refractive index point 1.66, relative density 3.22-3.31; porphyry metamorphic structure, superimposed chyme structure; mineral composition: opyroxene, jadeite, polysilicon Muscovite, a small amount of cinnamon, sphene, rutile, Zircon. Light grayish green jadeite, grease luster-glass gloss, opacity, refractive index point of 1.67-1.68, relative density 3.26-3.30, can be seen as "verdant"; fragmentation structure, local residual columnar granular mosaic structure; mineral composition is jadeite, a small amount of biotite, oblique tetrahedrite. Dark green jadeite, glass gloss, translucent, refractive index point measured 1.66, relative density 3.27-3.34, microalloyed structure, superimposed chyphon structure, mineral composition of pyroxene, jadeite, a little garnet. The infrared reflectance spectrum of blue-green jadeite mainly shows the characteristic peak of jadeite, the main peak value is 1081 cm-1954 cm-1582 cm-1524 cm-1470 cm-1435cm-1, and the infrared spectrum of grayish green jadeite is basically the same as that of standard jadeite. The main peak value is 1086 cm-1954 cm-1590 cm-1534 cm-1522 cm-1471 cm-1435 cm -1 and the main peak value is 1064cm-1961 cm-1562 cm-1521cm-1455 cm-1441 cm -1. The UV-Vis spectra of blue-green and grayish green jadeite have the absorption peak of 434nm in purple region, and the absorption peak of 436nm and 670 nm ~ 656 nm of red region caused by Cr3 in black green jadeite jade, which makes it appear pure green under transmitted light.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P619.281

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 陳晶晶;何明躍;白志民;;危地馬拉翡翠的寶石礦物學(xué)研究[J];科技通報(bào);2012年12期

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本文編號(hào)：1909651