Rhodochrosite Raman spectrum

The Rhodochrosite Raman spectrum and its interpretation are presented below.

Rhodochrosite sample data

Description: Rhodochrosite mineral sample
Mineral: Rhodochrosite
Ideal chemistry: MnCO3
Source: Grigore Cobălcescu Museum
Locality: Kohlenbach – Germany
Owner: Department of Geology – Alexandru Ioan Cuza University of Iasi

Rhodochrosite sample image

Rhodochrosite Raman spectrum

Raman spectrum of Rhodochrosite

Main Raman bands of Rhodochrosite

Wavenumbers (cm-1): 1094vs, 726w, 293m

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 Rhodochrosite

The Raman spectrum of rhodochrosite consists in a strongest intensity band at 1094 cm-1 assigned to symmetric stretching mode ν1 of CO3 group, the ν3 mode appears at 1439 cm-1 and the ν4 mode at 726 cm-1.

The observed vibrational bands of rhodochrosite 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 Beny, 1991 Free CO32- Assignment
184 T(Mn, CO3)
293 289 T(Mn, CO3)
726 718 680 ν4 symmetric CO3 deformation
879 ν2 asymmetric CO3 deformation
1094 1064
1063 ν1 symmetric CO3 stretching
1439 1414 1415 ν3 asymmetric CO3 stretching
1752 1725 ν1 + ν4

R* – rotational

The lower wavenumbers of rhodochrosite (293 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 1729 cm-1 may be regarded as the combination band of ν1 + ν4.

The positions of the observed Raman bands are in agreement with those reported by Beny, 1991.

References for the Raman spectrum of Rhodochrosite

  • 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]
  • BENY C. (1991) – Societe Francaise de Mineralogie et de Cristallographie – Base donnees de spectres Raman. Rhodochrosite [link]