珊瑚化石的红外光谱及XRD研究

通过红外吸收光谱和X射线粉晶衍射分析对不同颜色及质地且表面具放射状纹理的珊瑚化石的结构特征及组成物相进行了研究。结果表明，此类珊瑚化石主要由SiO₂组成，内部仍保留了钙质型珊瑚横断面所特有的放射状显微结构，成因属SiO₂交代作用。不同颜色和质地的珊瑚化石红外吸收光谱基本一致，均显示典型的石英质玉的红外吸收光谱特征。XRD分析表明不同颜色和质地的珊瑚化石主要组成物相一致，为SiO₂，其他矿物极微量，且不含CaCO₃。

Infrared Spectroscopy and XRD Studies of Coral Fossils

Coral fossil is an old remain of multicellular animal on the earth, and formed by various geological processes. The structural characteristics and compositions of the coral fossils with different color and radial texture on the surface were studied by infrared absorption spectroscopy and X-ray powder diffraction analyses. The results show that the studied coral fossils mainly are composed of SiO₂, and the radial microstructure characterized by the calcareous coral cross-section is preserved. It is formed by metasomatism by SiO₂. The infrared absorption spectra of the coral fossil with different color and texture are essentially the same, showing typical infrared absorption spectra of the quartz jade. XRD analysis shows that the main components of the coral fossils with different color and texture are consistent and mainly composed of SiO₂ with a trace amount of other minerals and without CaCO₃.