天然与仿制琥珀的宝石学鉴别特征

发布时间：2018-04-24 22:46

本文选题：天然琥珀 + 宝石学和谱学　；参考：《成都理工大学》2017年硕士论文

【摘要】：琥珀是一种树脂化石,由中生代白垩纪至新生代第三纪松柏科或豆科植物分泌的树脂被埋入地下,历经长时间的地质作用石化而成的。近年琥珀受到消费者的欢迎,市场上出现大量的仿制品,给消费者以及鉴定工作者带来不少困惑。本文结合前人的研究成果,以缅甸琥珀、抚顺琥珀、波罗的海琥珀及琥珀仿制品为研究对象,采用常规宝石学测试、显微岩相观察、激光拉曼光谱测试、红外光谱测试等方法,对其宝石学特征、谱学特征及化学成分进行研究;并结合三地琥珀的特征,探讨产地的不同对琥珀特征的影响,让人们进一步了解琥珀特性;通过对天然琥珀以及仿制品特征的对比研究,为天然琥珀与其仿制品的鉴定提供依据。观察测试表明,天然琥珀以黄色为主,其中缅甸琥珀多见棕红色,抚顺琥珀多为红色或橘色,波罗的海琥珀以明亮的黄色为主;琥珀原料为树脂光泽,抛光后呈树脂光泽至近玻璃光泽;透明度呈现过渡状态;折射率约为1.54;相对密度1.073g/cm3;摩氏硬度2~2.5,缅甸琥珀摩氏硬度略高可达到3;缅甸琥珀为强蓝白色荧光,抚顺琥珀多为浅蓝白色、蓝紫色荧光,波罗的海琥珀荧光反应弱;镜下观察,缅甸琥珀内部黑色杂质较多,波罗的海琥珀内部气泡较多,抚顺琥珀可见内部大量黑色杂质,呈流纹状分布。缅甸琥珀、抚顺琥珀、波罗的海琥珀的红外光谱大致相同,拉曼光谱峰值相差不大,都存在一定的特征。三产地的琥珀红外光谱主要存在3个特征处:位于2930、2830cm-1处由C-H饱和键伸缩振动所致的双吸收峰,位于1460、1383cm-1处由CH2-CH3弯曲振动所致的吸收峰,位于1157 cm-1处由C-O(羧酸脂)振动所致的吸收峰;拉曼光谱主要有三个特征峰区域:位于2923cm-1~2865cm-1区域出现因C-H键伸缩振动而出现的多个特征峰;位于1445cm-1附近因C-H键伸缩振动而出现的谱峰;1640cm-1附近因C=C键伸缩振动而出现的特征峰。结合天然琥珀的宝石学特征和谱学特征,对琥珀仿制品进行鉴别,主要结论如下:天然琥珀、优化处理琥珀、再造琥珀、“二代”琥珀以及天然树脂仿琥珀的常规宝石学性质基本相同。其他仿琥珀常规宝石学性质和天然琥珀具有明显区别。天然琥珀、优化处理琥珀以及再造琥珀具有相同的红外吸收光谱。某些处理琥珀和天然琥珀具有不同的显微结构。“二代”琥珀存在与天然琥珀相同的特征吸收峰,同时还存在其他物质的吸收峰;天然树脂的吸收光谱在3080cm-1处、1000~800cm-1区间具有吸收峰,其他与天然琥珀的红外吸收光谱相同。
[Abstract]:Amber is a kind of resin fossil, which was secreted from Mesozoic Cretaceous to Cenozoic Tertiary pine cypress or leguminous plants, and has been fossilized by geological processes for a long time. In recent years, amber has been welcomed by consumers, and a large number of imitation products have appeared in the market, which has brought a lot of confusion to consumers and appraisers. In this paper, the amber of Burma, Fushun Amber, Baltic Amber and Amber imitating products are used as the research objects. The methods of routine gemology test, microfacies observation, laser Raman spectroscopy and infrared spectroscopy are used. The Gemological characteristics, spectral characteristics and chemical constituents of amber were studied, and the influence of different producing areas on amber characteristics was discussed in order to make people understand amber characteristics further. The comparative study on the characteristics of natural amber and its imitation products provides a basis for the identification of natural amber and its imitation products. The observation and test showed that natural amber was mainly yellow, in which Burma amber was brownish red, Fushun amber was red or orange, Baltic amber was bright yellow, amber raw material was resin luster, Polished with resin gloss to near-glass gloss; transparency in transition state; refractive index about 1.54; relative density 1.073 g / cm ~ 3; Morse hardness 22.5, Myanmar Amber's hardness slightly high up to 3; Myanmar Amber is a strong blue-white fluorescence, Fushun Amber is mostly light blue and white, blue purple fluorescence is weak, Baltic Amber fluorescence reaction is weak, under the microscope, Myanmar Amber has more black impurities, Baltic Amber has more bubbles, Fushun Amber can see a large number of black impurities. It is distributed in the shape of flow pattern. The infrared spectra of amber, Fushun amber and Baltic amber are about the same. There are three main characteristics of the infrared spectrum of amber in the three producing areas: the double absorption peak caused by C-H saturated bond stretching vibration at 2930 ~ 2830 cm ~ (-1) and the absorption peak caused by CH2-CH3 bending vibration at 1460 ~ 1383 cm ~ (-1). At 1157 cm-1, the absorption peak is caused by C-O (carboxylate) vibration, and the Raman spectrum has three characteristic peaks: in the 2923cm-1~2865cm-1 region, there are many characteristic peaks due to C-H bond stretching vibration. The characteristic peak of C-H bond stretching vibration in the vicinity of 1445cm-1 is 1640cm ~ (-1). Combined with the gemological and spectral characteristics of natural amber, the main conclusions are as follows: natural Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber, Amber. The conventional gemstone properties of the second generation amber and natural resin imitating amber are basically the same. Other amber mimic conventional gemological properties and natural amber have obvious differences. Natural amber, optimized amber treatment and reconstituted amber have the same infrared absorption spectrum. Some treated amber and natural amber have different microstructure. The "second generation" amber has the same characteristic absorption peak as natural amber and the absorption peak of other substances, and the absorption spectrum of natural resin has the absorption peak in the range of 1000 ~ 800cm ~ (-1) at 3080cm-1, and the infrared absorption spectrum of other natural amber is the same as that of natural amber.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS933.23;TQ164

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