Spectroscopic characterization of natural corals.

The FTIR, micro-Raman, NMR, and XPS spectra of 25 different natural corals have been compared. Reflectance and transmission absorbance IR and Raman data have been used as rapid and efficient means of classification of natural corals containing aragonite (non-precious white species), calcite (red, pink, precious white species), and organic material (black protein polymer). The combination of reflectance IR and infrared microscopy could serve as a rapid, non-destructive method for distinguishing natural corals from artificial, fake jewels.

Application of reflectance micro-infrared spectroscopy in coal structure studies.

Fourier transform infrared micro-scale analysis of organic matter has been applied to characterise individual petrographic components of coal. The use of an infrared microscope made it possible to study and compare different parts of a single individual grain of vitrinite. This method enables analysis of particular macerals without the need for previous separation from coals.