利比亚沙漠玻璃的鉴定特征及成因

Identification Characteristic and Formation of Libyan Desert Glass

国家珠宝玉石质量监督检验中心收集了一些利比亚沙漠玻璃及其仿制品,并进行了一系列测试,包括红外光谱、拉曼光谱、X射线粉末衍射、X射线荧光能谱、电子探针等测试。通过测试发现:(1)利比亚沙漠玻璃与仿制品在红外反射光谱、透射光谱、拉曼光谱中峰位具有相似性,并不能确切区分;(2)近红外光谱中利比亚沙漠玻璃具有5200 cm^-1处吸收峰;(3)电子探针测试显示,利比亚沙漠玻璃和仿制品的化学成分仅在Fe元素含量上有所区别。根据水的存在方式推测其成因是陨石撞击浅滩或者经潜火山作用形成。

National Gemstone Testing Center collected and tested some Libyan desert glass and its corresponding imitations.The tests include infrared spectrum,Raman spectrum,X-ray powder diffraction,X-ray fluorescence spectrum,electron probe,etc..Through the tests,the authors found that:(1)There is little difference between the Libyan desert glass and the imitated products in the infrared reflection spectra,transmission spectra and Raman spectra,and it can not be distinguished exactly;(2)The Libyan desert glass has 5200 cm^-1 absorption peak in the near infrared spectrum;(3)The chemical composition of the Libyan desert glass and the imitated products is compared and analyzed with the electron probe,which reveals that the only difference between the two is the Fe content.According to the form of water existence,it can be inferred that the formation of the Libyan desert glass is caused by meteorite impact shoal or subvolcanism.