Some of the most common carbonates have been investigated by non-contact Raman spectroscopy. The synthetic alkali carbonates K₂CO₃ and Na₂CO₃ have also been studied. The Raman spectrum of aurichalcite is different from that of malachite. This spectrum has a characteristic intense band at 1069 cm^-1 which is assigned to the ν₁ symmetric stretching mode of the carbonate unit. The two low intensity Raman lines of 1485 and 1507 cm^-1 may be ascribed to the ν₃ asymmetric stretching modes. To the ν₄ mode (doubly degenerate symmetric bending) are attributed the values of 706 cm^-1 (ν_4a) and 733 cm^-1 (ν_4b). A number of bands with different intensities are observed in the lowest spectral shift (285, 388, 430, 461 and 498 cm^-1). These Raman lines are assigned to the CuO and ZnO stretching and bending vibrations. A single band of the OH-stretching modes is observed at 3344 cm^-1.

nonpolarized Raman spectra, carbonates, alkali carbonates, aurichalcite