Calcite Raman spectrum

The Calcite Raman spectrum and its interpretation are presented below.

Calcite sample data

Description: Calcite mineral sample
Mineral: Calcite
Ideal chemistry: CaCO3
Source: Grigore Cobălcescu Museum
Locality: Mexic
Owner: Department of Geology – Alexandru Ioan Cuza University of Iasi

Calcite sample image

Calcite Raman spectrum

Raman spectrum of Calcite

Main Raman bands of Calcite

Wavenumbers (cm-1): 1092vs, 715w, 285m

Raman parameters

Instrument settings: Raman spectrograph HE 532nm (Horiba Jobin-Yvon)
Spectral resolution: 2 cm-1
Conditions of measurement: at room temperature

Interpretation of Raman spectrum of Calcite

The intense band (ν1) of calcite spectrum corresponds to the symmetric stretching of CO3 group at 1092 cm-1. The ν2 (asymmetric deformation) vibration mode is not active in Raman. The values attributed to ν3 (asymmetric stretching) mode are 1437 cm-1 and ν4 (symmetric deformation) mode at 715 cm-1. Symmetric deformation or symmetric bending, also applies to asymmetric deformation.

The observed vibrational bands of calcite compared with well-documented values are listed below. The minor shift in positions may be due to the effects of natural impurities present in the sample (Buzgar and Apopei, 2009).

Buzgar and Apopei, 2009 Gunasekaran et al., 2006 Free CO32- Assignment
89 R(CO3)
162 T(Ca, CO3)
285 288 T(Ca, CO3)
715 716 680 ν4 symmetric CO3 deformation
879 ν2 asymmetric CO3 deformation
1092 1092 1063 ν1 symmetric CO3 stretching
1437 1437 1415 ν3 asymmetric CO3 stretching
1749 1754 ν1 + ν4

The lower wavenumbers of calcite (285 cm-1) observed in the above table, arise from the external vibration of the CO3 group that involve translatory oscillations of the group (relative translations between the cation and anionic group). In this spectrum are no values below 200 cm-1 because the spectral range is between 200 – 3400 cm-1.

A weak line observed at 1749 cm-1 may be regarded as the combination band of ν1 + ν4 (Gunasekaran et al., 2006).

References for the Raman spectrum of Calcite

  • BUZGAR N., APOPEI A. I. (2009) – The Raman study on certain carbonates. Analele Stiintifice ale Universitatii “Al. I. Cuza” – Iasi, Tome 55, issue 2, 97-112 [link]
  • GUNASEKARAN S., ANBALAGAN G., PANDI S. (2006) – Raman and infrared spectra of carbonates of calcite structure. Journal of Raman Spectroscopy, 37, p. 892-899 [link]